DESCRIPTION TITLE OF THE INVENTION Therapeutic or prophylactic agent for diabetes, obesity, dyslipidemia or metabolic syndrome, which comprises a benzylamine derivative represented by formula or a pharmaceutically acceptable acid addition salt thereof TECHNICAL FIELD [0001] The present invention relates to a therapeutic or prophylactic agent to diabetes, obesity, dyslipidemia or metabolic syndrome, which comprises a benzylamine derivative represented by formula or a pharmaceutically acceptable acid addition salt thereof. BACKGROUND ART [0002] Diabetes is a chronic disease caused by dysbolism leading to chronic hyperglycemic state by insufficient action of insulin. Diabetes is grouped into type 1 diabetes characterized by insufficient secretion of insulin and type 2 diabetes characterized by lowered secretion of insulin and lowered sensitivity (insulin resistance). In particular, type 2 diabetes, which accounts for 90 to 95% of diagnosed diabetes, is said to be closely correlated with the life-style diseases that worry men of today, such as obesity, hypertension, hyperlipemia and metabolic syndrome. [0003] Known diabetes drugs include sulfonylureas, phenylalanine derivatives, a-glucosidase inhibitors, biguanides, thiazolidine derivatives and the like, but use of these drugs is restricted, because of accompanied adverse reaction such as severe hypoglycemia, gastrointestinal tract disorder, liver function disorder or lactic acidosis. In addition, sulfonylureas and thiazoline derivatives are known to accelerate increase of body weight (Nonpatent Literature 1). [0004] Obesity, which is in the state where energy is stored abnormally in adipose tissue by overeating and lack of exercise, can cause type 2 diabetes and also hypertension, heart disease and others. [0005] Anti-obesity drugs include Mazindol, Orlistat, Rimonabant and the like. Mazindol has primary pharmacologic actions of central suppression of feeding and acceleration of heat production in peripheral organs, but is often accompanied with central adverse reactions such as nausea, headache and dizziness, and thus, strict control is needed for its use. Orlistat suppresses fat absorption and thus leads to decrease of body weight by inhibiting lipases, but it also inhibits absorption of lipophillic vitamins, and thus, vitamins should be supplemented, as needed. Rimonabant suppresses appetite and leads to decrease of body weight by interaction with cannabinoid 1 receptor, but has a problem of central adverse reactions such as dizziness, nausea and headache. These anti-obesity drugs have not only action to reduce body weight but also various disadvantages and adverse reactions, and for that reason, there exists a need for development of an anti-obesity drug that is more effective and superior in efficiency in use (Nonpatent Literatures 2 to 4). [0006] Dyslipidemia is a disease accompanied with abnormality in blood cholesterol and triglyceride levels. Dyslipidemia results in arteriosclerosis, further leading to increase of the risks of coronary disease such as angina cordis and myocardial infarction. Anti-dyslipidemia drugs are drugs for reduction of the blood triglyceride and LDL cholesterol levels that are important for prevention of coronary diseases (Nonpatent Literature 5). [0007] Anti-dyslipidemia drugs include statins (HMG-CoA reductase inhibitor) such as pravastatin and atrovastatin; bile acid absorbents such as cholestyramine and cholestimide; fibrates such as clofibrate and bezafibrate; and the like. Statins occasionally cause adverse reactions such as digestive organ symptoms and rhabdomyolysis. Bile acid absorbents have adverse reactions such as constipation and abdominal bloating and occasionally inhibit absorption of drugs used in combination. Fibrates should be used carefully with caution to the adverse reactions such as rhabdomyolysis and liver function disorder. All of these anti-dyslipidemia drugs have action to decrease serum triglyceride or cholesterol level, but, in fact, they also have various disadvantages and adverse reactions (Nonpatent Literature 2). [0008] Metabolic syndrome is a syndrome in combination of some of abdominal obesity, hypertriglyceridemia, hypo-HDL-cholestrolemia, hyperglycemia and hypertension, and it is considered to be a syndrome higher in the risk of arteriosclerotic diseases, because these symptoms in combination leads to increase of the risk of arteriosclerotic diseases. [0009] As for the diagnostic standard of metabolic syndrome, for example, National Cholesterol Education Program (hereinafter, NCEP) in 2001 defines, as the metabolic syndrome, a syndrome that have values higher than standards at least in three risk factors among the risk factors 1 to 5 shown in Table 1. The International Diabetes Federation (hereinafter, IDF) and the Examination Committee of Criteria for Obesity Disease in Japan (joint committee of eight academic societies including Japan Atherosclerosis Society, Japan Diabetes Society and others) define, as the metabolic syndrome, a syndrome showing abdominal obesity as essential item and additionally multiple items selected from hypertriglyceridemia, hypo-HDL-cholesterolemia, hypertension and hyperglycemia. Because the risk factors are treated only individually in chemical treatment of metabolic syndrome, there exists a need for a drug that is effective to multiple risk factors even as a single drug (Nonpatent Literatures 6 and 7). [0010] [0011] Under the circumstance above, 03 adrenoreceptor agonists are proposed as a new drug candidate to type 2 diabetes and obesity (Nonpatent Literatures 8 and 9). The J33 adrenoreceptors, which are present in the fat cells of rodents and human, are suggested to have an important role in regulation of fat decomposition and heat production (Nonpatent Literatures 10 and 11). Functional deterioration of (33 adrenoreceptor results, for example, in accumulation of body fat and thus, its correlation with development of obesity is suggested (Nonpatent Literature 12). However, development of a P3 adrenoreceptor agonist as diabetes drug is so far unfruitful, because of the adverse reactions on the cardiovascular system. [0012] Patent Document 1 discloses a P3 adrenoreceptor agonist (amine derivative). However, there is no disclosed pharmacological data showing the efficacy thereof to diabetes and obesity. [0013] Nonpatent Literature 8 discloses the following benzylamine derivative (1) as a (33 adrenoreceptor agonist. However, the data available concerning the efficacy thereof to diabetes and obesity is only limited to the action of decomposing free fatty acids. [0014] [0015] No drug is developed from the benzylamine derivative (1) above and analogous benzylamine derivatives, which are fJ3 adrenoreceptor agonists, because there are adverse reactions on the cardiovascular system (prolongation of QT interval and increase of heart rate) (Nonpatent Literatures 8 and 13). [0016] Alternatively, Patent Document 2 discloses a wide range of compounds including part of the benzylamine derivatives (1) above. However, usefulness of these compounds to diabetes, obesity, dyslipidemia or metabolic syndrome is currently unknown. PRIOR ART LITERATURE PATENT DOCUMENTS [0017] Patent Document 1: JP-ANo. 7-206806 Patent Document 2: USP No. 3341584 Patent Document 3: WO 2008/093767 NONPATENT LITERATURES [0018] Nonpatent Literature 1: Japan Diabetes Society Ed., "Diabetes Treatment Guide 2008-2009", 2008 Nonpatent Literature 2: Japan Pharmaceutical Information Center Ed., "Medical Drugs 2008", 2007 Nonpatent Literature 3: Takahashi et al., "Igakuno Ayumi", 2005,213,6, P.549 Nonpatent Literature 4: Saiki et al., "Igakuno Ayumi", 2005,213,6, P.643 Nonpatent Literature 5: Kinoshita, "Saishin Igaku", 2008,63,2, P.7 Nonpatent Literature 6: Hirata et al., "Saishin Igaku", 2006, 61, 3 (Special Issue), P.579 Nonpatent Literature 7: Okada et al., "Saishin Igaku", 2008,63,2, P.262 Nonpatent Literature 8: Washburn et al., Bioorg. Med. Chem. Lett., 2001, 11, P.3035 Nonpatent Literature 9: Harada et al., Chem. Pharm. Bull., 2005,53, P. 184 Nonpatent Literature 10: Howe et al., Drug Future, 1993,18, P.529 Nonpatent Literature 11: Arch et al., J. Med. Res. Rev., 1993,13, P.663 Nonpatent Literature 12: Revelli et al., J. Clin. Invest., 1997,100, P. 1098 Nonpatent Literature 13: Gavai et al., Bioorg. Med. Chem. Lett., 2001,11, P.3041 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION [0019] Thus, an object of the present invention is to provide a therapeutic or prophylactic agent for diabetes, obesity, dyslipidemia or metabolic syndrome, which can exhibit significant efficacy at lower dose and does not have an increase of heart rate or a prolongation of QT interval which is an adverse side effect on the cardiovascular system. MEANS TO SOLVE THE PROBLEMS [0020] After intensive studies to achieve the object, the inventors have found that in in-vivo studies by using type 2 diabetes model mice (KK/Ay mice) and diabetes-obesity model mice (Diet Induced Obesity mice: hereinafter, referred to as DIO mice), a new benzylamine derivative superior in selectivity to |33 adrenoreceptor has a favorable efficacy to diabetes, obesity, dyslipidemia or metabolic syndrome, but does not have the adverse reactions on the cardiovascular system (prolongation of QT interval and increase of heart rate), which is a serious problem associated with chemical therapy of chronic diseases, and made the present invention. [0021] Thus, the present invention provides a therapeutic or prophylactic agent to diabetes, obesity, dyslipidemia or metabolic syndrome, which comprises a benzylamine derivative represented by General Formula (I) [wherein, R1 represents an alkyl group having 1 to 6 carbon atoms; R2 represents an alkyl group having 1 to 6 carbon atoms; R3 and R5 each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms; and R4 represents a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms] or a pharmaceutically acceptable acid addition salt thereof. [0022] In the therapeutic or prophylactic agent above, R1 is preferably methyl, ethyl, propyl, isopropyl or tert-butyl; R2 is preferably methyl, ethyl, propyl or isopropyl; R3 and R5 are each independently preferably methyl, ethyl, fluoromethyl, difluoromethyl, trifluoromethyl, methoxy, ethoxy or chloro; and R4 is preferably a hydrogen atom, methoxy, ethoxy, propoxy or isopropoxy. [0023] More preferably in the therapeutic or prophylactic agent above, R2 is methyl; R3 and R5 are each independently methyl, ethyl, fluoromethyl, difluoromethyl, trifluoromethyl, methoxy, ethoxy or chloro; and R4 is a hydrogen atom, methoxy, ethoxy, propoxy or isopropoxy, and more preferably, R1 and R are methyl; R3 and R5 are each independently methyl, trifluoromethyl, methoxy or chloro; and R4 is a hydrogen atom or methoxy. [0024] Still more preferably in the therapeutic or prophylactic agent above, R1 and R2 are methyl; R and R5 are simultaneously methyl, trifluoromethyl, methoxy or chloro; and R4 is a hydrogen atom. [0025] The present invention also provides a method for therapy or prophylaxis of diabetes, obesity, dyslipidemia or metabolic syndrome, comprising administering an effective amount of the above-described therapeutic or prophylactic agent. [0026] Further, the present invention provides use of a benzylamirie derivative represented by General Formula (I) above or a pharmaceutically acceptable acid addition salt thereof in production of a pharmaceutical for treatment or prevention of diabetes, obesity, dyslipidemia or metabolic syndrome. ADVANTAGEOUS EFFECTS OF THE INVENTION [0027] The therapeutic or prophylactic agent according to the present invention shows distinctive therapeutic or preventive effect to diabetes, obesity, dyslipidemia or metabolic syndrome without adverse reactions to the cardiovascular system such as increase of heart rate and prolongation of QT interval. BRIEF DESCRIPTION OF THE DRAWINGS [0028] Figure 1 is a chart showing the influence of the compound of Example 1 on the blood sugar-reducing action after administration of insulin. The abscissa shows the time (minutes) after insulin administration, while the ordinate shows the blood sugar level of mouse. ###p<0.001 vs. normal mice (vehicle administered group), *p<0.05 and **p<0.01 vs. DIO mice (vehicle administered group) (parametric Williams test, respectively tested at each point). Figure 2 is a chart showing the influence of the compound of Example 1 on the hear rate of conscious rat. The abscissa shows the period (minutes) after drug administration, while the ordinate shows the heart rate of rat. DESCRIPTION OF THE EMBODIMENTS [0029] The terms below used in the present description are defined as follows, unless specified otherwise. [0030] The term "alkyl" group means a monovalent linear or branched saturated hydrocarbon group consisting of carbon and hydrogen atoms. [0031] The term "alkoxy" group means an -OR group, in which R is the alkyl as defined herein. [0032] The term "halogen" atom means fluoro, chloro, bromo or iodo. [0033] The term "haloalkyl" group means an alkyl as defined herein of which hydrogen atoms are replaced with the one or more halogen atoms as defined herein at an arbitrary position. [0034] The term "diabetes" means a disease diagnosed as diabetes according to the diagnostic standard, for example, of WHO (World Health Organization), Japan Diabetes Society, American Diabetes Association or European Association for the Study of Diabetes and include type 1 diabetes, type 2 diabetes, pregnancy diabetes, and the like. The type 2 diabetes is characterized by its resistance to the action of insulin, i.e., "insulin resistance". [0035] The "insulin resistance" means a disease diagnosed as insulin resistance, based on theinsulin resistanceindex(fasting bloodsugar(mg/dL)xfastinginsulin (uU/mL)*-405) or on the results obtained by examination by glucose clamp method or the like and includes syndrome X additionally. In addition to type 2 diabetes, diseases with "insulin resistance" include, for example, fatty liver, particularly NAFLD (non-alcoholic fatty liver disease), NASH (non-alcoholic steatohepatitis), coronary heart diseases (CHDs), arteriosclerotic diseases, hyperglycemia, lipodosis, impaired glucose tolerance, hypertension, hyperlipemia, diabetes complications, pregnancy diabetes, polycystic ovary syndrome and the like. [0036] The term "dyslipidemia" means a disease diagnosed as dyslipidemia according to the diagnostic standard, for example, of WHO or Japan Atherosclerosis Society and includes hyperlipemia, hypercholestrolemia, hyper-LDL-cholestrolemia, hypo-HDL-cholestrolemia, hypertriglyceridemia and the like. [0037] The term "obesity" means a disease diagnosed as obesity according to the diagnostic standard, for example, of WHO or Japan Society for the Study of Obesity and include "overweight" and others. [0038] The term "metabolic syndrome" means a disease diagnosed as metabolic syndrome according to the diagnostic standard, for example, of WHO, NCEP, IDF or the Committee for Diagnostic Standard of Metabolic Syndrome in Japan Atherosclerosis Society. [0039] The term "therapeutic or prophylactic agent" includes an agent used for treatment or prevention and also an agent used both for treatment and prevention simultaneously. [0040] The therapeutic or prophylactic agent for diabetes, obesity, dyslipidemia or metabolic syndrome of the present invention is characterized by containing a benzylamine derivative represented by General Formula (I): ¦\ » t [wherein, R1 represents an alkyl group having 1 to 6 carbon atoms; R2 represents an alkyl group having 1 to 6 carbon atoms; R3 and R5 each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms; and R4 represents a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms] or a pharmaceutically acceptable acid addition salt thereof. [0041] In the benzylamine derivatives represented by General Formula (I), examples of the alkyl groups having 1 to 6 carbon atoms of R1, R2, R3 and R5 include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl and the like. [0042] Examples of the haloalkyl groups having 1 to 6 carbon atoms of R3 and R5 include, but are not limited to, fluoromethyl, chloromethyl, difluoromethyl, dichloromethyl, trifluoromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 2,2,2-trichloroethyl and the like. [0043] Examples of the alkoxy groups having 1 to 6 carbon atoms of R3, R4 and R5 include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy and the like. [0044] Examples of the halogen atoms of R3 and R5 include, but are not limited to, fluoro, chloro, bromo, iodo and the like. [0045] Typical favorable examples of R1 to R5 are shown below. However, these groups are only typical examples, and R1 to R5 are not limited to these groups. [0046] R1 is preferably methyl, ethyl, propyl, isopropyl or tert-butyl, more preferably methyl or isopropyl, and still more preferably methyl. [0047] R2 is preferably methyl, ethyl, propyl or isopropyl, more preferably, methyl, ethyl or propyl, and still more preferably methyl. [0048] R3 and R5 are each independently, preferably methyl, ethyl, fluoromethyl, difluoromethyl, trifluoromethyl, methoxy, ethoxy or chloro, more preferably methyl, trifluoromethyl, methoxy or chloro, and R3 and R5 are still more preferably simultaneously methyl, trifluoromethyl, methoxy or chloro. [0049] R4 is preferably a hydrogen atom, methoxy, ethoxy, propoxy or isopropoxy, more preferably a hydrogen atom, methoxy or ethoxy, and still more preferably a hydrogen atom or methoxy. [0050] The benzylamine derivative represented by General Formula (I) has two asymmetrical carbon atoms, so that optical isomers and diastereomers which are based thereon exist. The present invention also includes these single isomers or a racemate or diastereomer mixture thereof. [0051] Examples of the pharmaceutically acceptable acid addition salts of the benzylamine derivative represented by General Formula (I) include, but are not limited to, inorganic acid salts such as hydrochloric acid salt, sulfuric acid salt, nitric acid salt, hydrobromic acid salt, hydroiodic acid salt and phosphoric acid salt; organic carboxylic acid salts such as acetic acid salt, lactic acid salt, citric acid salt, oxalic acid salt, glutaric acid salt, malic acid salt, tartaric acid salt, fumaric acid salt, mandelic acid salt, maleic acid salt, benzoic acid salt and phthalic acid salt; organic sulfonic acid salts such as methanesulfonic acid salt, ethanesulfonic acid salt, benzenesulfonic acid salt, p-toluenesulfonic acid salt and camphorsulfonic acid salt; and the like.More favorable among them are hydrochloric acid salt, hydrobromic acid salt, phosphoric acid salt, tartaric acid salt and methanesulfonic acid salt; and still more favorable are hydrochloric acid salt, tartaric acid salt and methanesulfonic acid salt; but the favorable examples are not limited to these salts above. [0052] Typical preferable examples of the benzylamine derivatives represented by General Formula (I) are shown in Table 2, but the present invention is not limited to these examples. [0054] The benzylamine derivatives of the present invention, represented by General Formula (I) can be produced by a method suitable to the characteristics thereof such as the basic skeleton and the kinds of the substituent groups. The starting materials and reagents used for production of these compounds are generally commercially available or can be synthesized by a procedure known by those who are skilled in the art, according to a method described in reference literature such as Peter et al., "Organic Reaction", Wiley & Sons or Fieser, "Fieser and Fieser's Reagent for Organic synthesis", Wiley & Sons and the like. [0055] A typical example of the method of producing the benzylamine derivatives of the present invention, represented by General Formula (I) is that shown in Scheme 1. [0056] [0057] To put it concretely the benzylamine derivative represented by General Formula (I) can be obtained using a method known to those who are skilled in the art, for example, by reductive alkylation of an amine derivative represented by General Formula (II) with a benzaldehyde derivative represented by General Formula (III). [0058] The solvents that may be used include aprotic polar solvents such as dimethylformamide (DMF), dimethylacetamide and dimethylsulfoxide (DMSO); ether solvents such as diethylether, tetrahydrofuran (THF), dimethoxyethane (DME) and dioxane; hydrocarbon solvents such as benzene, toluene and xylene; halogenated solvents such as dichloromethane, chloroform and 1,2-dichloroethane; alcoholic solvents such as methanol, ethanol and propanol; or the mixed solvents thereof. Normally, use of an alcoholic solvent such as methanol or ethanol, in particular methanol, gives favorable results. The benzaldehyde derivative (III) can be used in an amount of 0.5 to 20 equivalents to the amine derivative (II), but the ratio used normally, 0.5 to 10 equivalents, preferably 0.5 to 3 equivalents. [0059] The reducing agents that may be used include sodium borohydride, sodium cyanoborohydride, sodium triacetoxyborohydride, borane-pyridine complex and the like, and, in particular, sodium cyanoborohydride and borane-pyridine complex are used favorably. The reducing agent can be used in an amount of 0.5 to 50 equivalents to the amine derivative (II), but the ratio used is normally, 1 to 20 equivalents, preferably 1 to 10 equivalents. [0060] A reaction temperature normally of -40 to 150°C, preferably of -30 to 80°C, gives satisfactory results. The reaction time is selected properly according to the conditions such as reaction temperature, but normally a reaction time of 30 minutes to 10 hours gives satisfactory results. The concentration of the amine derivative (II) in the reaction mixture is not particularly limited, but normally, preferably 0.001 to 1 mol/L. [0061] It is possible to convert the benzylamine derivative (I) thus obtained to its acid addition salt by adding an acid to the solution thereof in a suitable solvent. The solvents that may be used include halogenated solvents such as dichloromethane, chloroform and 1, 2-dichloroethane; alcoholic solvents such as methanol, ethanol and propanol; ether solvents such as dioxane and diethylether, or the mixed solvents thereof. Normally, use of an alcoholic or ether solvent, in particular methanol, propanol or dioxane, gives favorable results. The amount of the acid added is not particularly limited, but the ratio is within the range of 1 to 30 equivalents with respect to the benzylamine derivative (I), and normally, a ratio of 1 to 10 equivalents, preferably 1 to 5 equivalents, gives satisfactory results. [0062] The amine derivative represented by General Formula (II), which is used as the starting material in Scheme 1, can be obtained for example, by debenzylation which is a method known to those who are skilled in the art of the amine represented by General Formula (TV), which can be synthesized by the method described in WO 2005/040093, as shown in Scheme 2. The debenzylation is generally carried out by hydrogenolysis in the presence of a metal catalyst. [0063] [wherein, R1 and R2 are the same as those defined above, and Bn represents a benzyl group.] [0064] Use of an alcoholic solvent such as methanol, ethanol or propanol as the reaction solvent gives favorable results. Alternatively, an ether solvent such as tetrahydrofuran (THF), dimethoxyethane (DME) or dioxane may be used as it is, but use of a mixture with an alcoholic solvent such as methanol or ethanol gives favorable results. Catalysts commonly used in hydrogenation reaction, such as platinum oxide, palladium hydroxide and palladium-carbon, can be used as the metal catalysts above, but palladium hydroxide and palladium-carbon are used favorably. The metal catalyst can be used in an amount of 0.001 to 50 equivalents with respect to the amine (IV), but the ratio used is normally 0.05 to 20 equivalents, preferably 0.1 to 5 equivalents. The reaction can be carried out at a reaction temperature of-30 to 80°C, preferably 10 to 50°C, and at a hydrogen pressure of 1 to 100 atmospheres, preferably 1 to 30 atmospheres, but normally, combination of room temperature and normal pressure gives favorable results. The reaction time is selected properly according to the reaction condition, but normally, a reaction time of 30 minutes to 48 hours gives favorable results. The concentration of the substrate (IV) in the reaction mixture is not particularly limited, but normally, preferably 0.001 to 1 mol/L. [0065] The efficacy of treatment to diabetes, obesity, dyslipidemia or metabolic syndrome with the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt can be determined by using normal and disease-model animals, such as mice, rats, dogs, and monkeys, (for example, diabetes/obesity model animals described in Takeuchi et al., "Folia Pharmacologica Japonica", 2006, 128, p.37-41 and diabetes/obesity mice described in Winzell M.S. et al., Diabetes, 2004, 53, p. S215-S219), but the test animals are not limited thereto. The fact that the concern about the adverse reactions to the cardiovascular system possibly caused by the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt is very limited can be confirmed, for example, by the method described in Salgado et al., Am. J. Physiol. Heart Circ. Phiyol., 2007, 292, p. 593-600, by examining the functions of cardiovascular organs of small animals in the awake state, although the test method is not limited thereto. [0066] Efficacy in treatment of diabetes with the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt can be determined, for example, based on clinical symptoms (e.g., blood sugar or plasma glucose concentration), diabetes-related test results (e.g., blood glycated Hemoglobin Ale: HbAlC) or blood sugar in oral glucose tolerance test (OGTT) after two hours. Specifically, compared to individuals to which the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt is not administered, individuals having the compound administered likely have advantageous actions such as decrease or improvement in blood sugar or plasma glucose concentration, decrease of blood glycated HbAlC and decrease in the blood sugar in OGTT after two hours. The blood sugar and the plasma glucose concentration can be determined by using a simple blood sugar analyzer, which determines blood sugar, by using a reaction of glucose oxidase, based on the principle of detecting absorbance in colorimetric method or quantitative electrochemical determination (glucose sensor method). [0067] Efficacy of the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt in treatment to the diseases with "insulin resistance" can be determined by using, as indicator, the glucose utilization rate or the glucose injection rate of individuals when insulin is injected in glucose clamp test. Insulin tolerance test (ITT) is generally used as a simple and convenient method of evaluating the insulin resistance state of individuals, and specifically, insulin sensitivity is evaluated by using the change in blood sugar under insulin load as an indicator (Tanaka et al., Proc. Natl. Acad. Sci, 2003,100, P. 15924-15929). Thus, compared to individuals who are not administered with the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt, those with the compound administered are possibly alleviated from the state when the blood sugar-decreasing action by insulin deteriorated. In this way, it is possible to make the blood sugar-decreasing action inherent to insulin expressed sufficiently. [0068] Efficacy of the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt in treatment of dyslipidemia can be evaluated by using the plasma triglyceride level of individuals as an indicator. Thus, compared to individuals who are not administered with the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt, those with the compound administered are likely have advantage of reduced blood triglycerides. Triglycerides can be determined by using a measurement kit of colorimetric method by using a commercially available enzyme reaction. [0069] Efficacy of the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt in treatment of obesity can be evaluated by using the body weight, abdominal circumference, body mass index (BMI) or internal fat level of individuals as an indicator. Thus, compared to individuals who are not administered with the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt, those with the compound administered are likely lower in the body weight, abdominal circumference, body mass index (BMI) or internal fat level of the individuals. [0070] In addition, the drug containing the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt is effective not only to human, but also to mammals other than human, such as mouse, rat, hamster, rabbit, cat, dog, bovine, sheep and monkey. [0071] When the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt is used clinically as a therapeutic or prophylactic agent for diabetes, obesity, dyslipidemia or metabolic syndrome, the drug may be the free base or the acid addition salt itself or a mixture thereof with suitable additives such as diluents, stabilizers, preservatives, buffers, solubilizing agents, emulsifiers, diluent and isotonic agents. Examples of the administration forms include oral preparations such as tablets, capsules, granules, powders, and syrups; parenteral preparations such as injections, suppositories and solutions; local administration preparations such as ointments, creams and patches; and the like. [0072] The therapeutic or prophylactic agent for diabetes, obesity, dyslipidemia or metabolic syndrome according to the invention desirably contains the active ingredient in an amount of 0.00001 to 90 wt %, more preferably 0.0001 to 70 wt %. The amount thereof is selected properly according to the symptom, age, body weight, administration method and the like, but the therapeutic or prophylactic agent can be administered to an adult as the active ingredient in an amount of 0.1 ug to 1 g per day in the case of injection, 1 ug to 10 g in the case of oral preparation, and 1 Ug to 10 g in the case of patch, and it can be administered all at once or several times in portions a day. [0073] The benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt can be used in combination with other diabetes drugs, drugs for treatment of diseases with "insulin resistance", anti-obesity drugs, anti-dyslipidemia drugs, and metabolic syndrome drugs (hereinafter, referred to as combination drugs). The time of administration of the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt and the combination drug is not particularly limited, and these drugs may be administered to a patient simultaneously or separately with time difference. The amount of the combination drug administered can be selected properly according to the application clinically used. The blending ratio of the benzylamine derivative represented by General Formula (I) or the pharmaceutically acceptable acid addition salt to the combination drug can be selected properly according to the patient to be administered, administration route, symptom, combination and others. [0074] Examples of the combination drugs used then include insulin preparations (ultrafast-acting insulin preparations, fast-acting insulin preparations, mixed insulin preparations, intermediate insulin preparations, long-acting insulin preparations, long-acting soluble insulin preparation, transpulmonary insulin preparation, oral insulin preparation, etc.), insulin resistance-improving drugs (pioglitazone, rosiglitazone, netoglitazon, farglitazar, rivoglitazone, balaglitazone, etc.), a-glucosidase inhibitors (acarbose, voglibose, miglitol, emiglitate, etc.), biguanides (metformin, buformin, etc.), sulfonyl ureas (tolbutamide, acetohexamide, chlorpropamide, tolazamide, glyclopyramide, glybuzole, glibenclamide, gliclazide, glimepiride, glipizide, gliquidone, etc.), fast-acting insulin secretion stimulators (nateglinide, repaglinide, mitiglinide, etc.), GLP-1 agonists (exenatide, liraglutide, etc.), amylin agonists (pramlintide, etc.), DPP-IV inhibitors (vildagliptin, sitagliptin, saxagliptin, alogliptin, denagliptin, etc.), (33 adrenoreceptor agonists (Solabegron, KRP-204, YM-178, etc.), fructose-1,6-bisphosphatase inhibitors (MB-6322, MB-07803, etc.), SGLT (sodium-dependent renal glucose transporter) inhibitors (sergliflozin, AVE-2268, GSK-189075, TS-033, KGA-2727, SAR-7226, etc.), llp-HSDl inhibitors (BVT-3498, AMG-221, INCB-13739, INCB-20817, etc.), PTP-1B (protein tyrosine phosphatase-lB) inhibitors (ISIS-113715, JTT-551, etc.), GSK3p (glycogen synthase kinase 30) inhibitors (SAR-502250, etc.), glucagon antagonists (BAY-27-9955, NN-2501, etc.), glycogen phosphorylase inhibitors (Isofagomine, PSN-357, etc.), CPT1 (carnitine palmitoyltransferase 1) inhibitors (teglicar, etc.), glucocorticoid antagonists (mifepristone, KB-3305, etc.), HMG-CoA reductase inhibitors (pravastatin, simvastatin, fluvastatin, atorvastatin, pitavastatin, etc.), anion exchange resins (colestyramine, cholestimide, etc.), fibrates (clofibrate, clinofibrate, bezafibrate, fenofibrate, etc.), nicotinic acid-based drugs (tocopherol nicotinate, CB1 (cannabinoid 1) antagonists, rimonabant, surinabant, MK-0364, AVE-1625, etc.), lipase inhibitors (orlistat, etc.), central appetite inhibitors (mazindol, fenfluramine, dexfenfluramine, sibutramine, phentermine, etc.) and the like. EXAMPLES [0075] Hereinafter, the present invention will be described specifically with reference to Examples. [0076] (Comparative Example 1) N-(5-((lR^2S)-2-Amino-l-hydroxypropyl)-2-hydroxyphenyl)methanesulfonamide (3) [0078] 10% palladium/carbon (60 mg) was added to a methanol solution (6 mL)of an amine derivative (2) (195 mg, 0.556 mmol) prepared according to the method described in Comparative Example 1 of WO2005/040093 and the mixture was stirred at room temperature under hydrogen atmosphere for 2.5 hours. The reaction mixture was filtered, and the filtrate was then concentrated, to give a desired amine (3) as a brown solid (153 mg). The desired amine (3) was used in the following step without purification. *H NMR (400 MHz, CD3OD) 8(ppm): 1.15 (d, J=6.8 Hz, 3H), 2.97 (s, 3H), 3.46 (m, 1H), 4.85 (d, J=3.4 Hz, 1H), 6.95 (d, J=8.3 Hz, 1H), 7.14 (dd, J=2.2, 8.3 Hz, 1H), 7.40 (d, J=2.2 Hz, 1H) [0079] (Example 1) N-(5-((lR,2S)-2-(3,5-Dimemoxybenzylamino)-l-hydroxypropyl)-2-hydroxyphen yl)methanesulfonamide (4) [0080] [Formula 7] [0081] Borane-pyridine complex (445 uL, 4.18 mmol) was added to a methanol solution (10 mL) of an amine (3) (363 mg, 1.39 mmol) and 3,5-dimethoxybenzaldehyde (301 mg, 1.81 mmol), and the mixture was stirred for two hours. The reaction mixture was allowed to cool to room temperature and extracted after addition of water with a mixed solvent (ethyl acetate: methanol=10:l), and the organic layer was washed with saturated aqueous sodium chloride solution. The organic layer was dried and concentrated, and the crude product obtained was purified by amine silica gel column chromatography (eluant: chloroform: methanol=7:l), to give a desired amine (4) as a pale yellow solid (329 mg, yield: 57%). *H NMR (400 MHz, CD3OD) 5(ppm): 1.11 (d, J=6.4 Hz, 3H), 2.83 (m, 1H), 2.89 (s, 3H), 3.61 (d, J=13.2 Hz, 1H), 3.73 (d, J=13.2 Hz, 1H), 3.73 (s, 6H), 4.48 (d, J=6.0 Hz, 1H), 6.34 (t, J=2.4 Hz, 1H), 6.37 (d, J=2.4 Hz, 2H), 6.84 (d, J=8.0 Hz, 1H), 6.99 (dd, J=2.0, 8.0 Hz, 1H), 7.32 (d, J=2.0 Hz, 1H) [0082] 4N Hydrogen chloride dioxane solution (0.04 mL) was added to the dioxane solution (1 mL) of the obtained amine (4) (47 mg, 0.11 mmol), and the mixture was freeze-dried, to give hydrochloric acid salt of the amine (4) as white solid (27 mg, yield: 55%). *H NMR (400 MHz, DMSOd6) 8(ppm): 1.00 (d, J=6.8 Hz, 3H), 2.91 (s,3H), 3.23 (m, 1H), 3.76 (s, 6H), 4.18 (m, 2H), 5.13 (br, 1H), 6.03 (d, J=3.6 Hz, 1H), 6.51 (t, J=2.4 Hz, 1H), 6.86 (d, J=2.4 Hz, 2H), 6.92 (d, J=8.0 Hz, 1H), 6.99 (dd, J=2.0, 8.0 Hz, 1H), 7.18 (d, J=2.0 Hz, 1H), 8.78 (s, 1H), 9.10 (br, 1H), 9.19 (br, 1H), 10.00 (s,lH) [0083] (Example 2) N<5<(lR,2S)-2<3,5-Bis(trifluoromethyl)benzylamino)-l-hydroxypropyl)-2-hydr oxyphenyl)methanesulfonamide (5) [0084] [Formula 8] [0085] Borane-pyridine complex (130 uL, 1.24 mmol) was added to a methanol solution (4 mL) of an amine (3) (107 mg, 0.41 mmol), 3,5-bis(trifluoromethyl)benzaldehyde (90 uL, 0.54 mmol) at 40°C and the mixture was stirred for 1.5 hours. The reaction mixture was allowed to cool to room temperature and extracted after addition of water with a mixed solvent (ethyl acetate: methanol=10:l), and the organic layer was washed with saturated aqueous sodium chloride solution. The organic layer was dried and concentrated, and the crude product obtained was purified by amine silica gel column chromatography (eluant: chloroform: methanol=7:l), to give a desired amine (5) as a white solid (132 mg, yield: 66%). *H NMR (400 MHz, CD3OD) 8(ppm): 1.07 (d, J=6.4 Hz, 3H), 2.80 (m, 1H), 2.90 (s, 3H), 3.87 (d, J=14.0 Hz, 1H), 3.95 (d, J=14.0 Hz, 1H), 4.55 (d, J=5.6 Hz, 1H), 6.85 (d, J=8.4 Hz, 1H), 7.02 (dd, J=2.0, 8.0 Hz, 1H), 7.34 (d, J=2.0 Hz, 1H), 7.81 (brs, 1H), 7.89 (brs, 2H) [0086] (Example 3) N-(5-((l R,2S)-2-(3,5-Dichlorobenzylamino)-1 -hydroxypropyl)-2-hydroxyphenyl) methanesulfonamide (6) [0087] [Formula 9] [0088] Borane-pyridine complex (130 uL, 1.21 mmol) was added to an methanol solution (4 mL) of an amine (3) (105 mg, 0.40 mmol) and 3,5-dichlorobenzaldehyde (95 mg, 0.52 mmol) at 40°C and the mixture was stirred for 1.5 hours. The reaction mixture was allowed to cool to room temperature and extracted after addition of water with a mixed solvent (ethyl acetate: methanol-10:1), and the organic layer was washed with saturated aqueous sodium chloride solution. The organic layer was dried and concentrated, and the crude product obtained was purified by amine silica gel column chromatography (eluant: chloroform: methanol=7:l), to give a desired amine (6) as a white solid (76 mg, yield 45%). *H NMR (400 MHz, CD3OD) 8(ppm): 1.07 (d, J=6.4 Hz, 3H), 2.76 (m, 1H), 2.91 (s, 3H), 3.67 (d, J=14.0 Hz, 1H), 3.76 (d, J=14.0 Hz, 1H), 4.48 (d, J=5.6 Hz, 1H), 6.86 (d, J=8.4 Hz, 1H), 7.01 (dd, J=2.0,8.4 Hz, 1H), 7.20 (d, J=2.0 Hz, 2H), 7.29 (t, J=2.0 Hz, 1H), 7.32 (d, J=2.0 Hz, 1H) [0089] (Example 4) N-(2-Hydroxy-5-((lR,2S)4-hydroxy-2<3,4,5-trimethoxybenzylamino)propyl)phe nyl)methanesulfonamide (7) [0090][Formula 10] [0091] Borane-pyridine complex (135 uL, 1.28 mmol) was added to a methanol solution (4 mL) of an amine (3) (111 mg, 0.43 mmol) and 3,4,5-trimethoxybenzaldehyde (111 mg, 0.55 mmol) at 40°C and the mixture was stirred for 1.5 hours. The reaction mixture was allowed to cool to room temperature and extracted after addition of water with a mixed solvent (ethyl acetate: methanol=10:l), and the organic layer was washed with saturated aqueous sodium chloride solution. The organic layer was dried and concentrated, and the crude product obtained was purified by amine silica gel column chromatography (eluant: chloroform: methanol=7:l), to give a desired amine (7) as a white solid (67 mg, yield 36%). !H NMR (400 MHz, CD3OD) 8(ppm): 1.12 (d, J=6.4 Hz, 3H), 2.82 (m, 1H), 2.89 (s, 3H), 3.61 (d, J=12.8 Hz, 1H), 3.72 (s, 3H), 3.73 (d, J=12.8 Hz, 1H), 3.80 (s, 6H), 4.46 (d, J=6.4 Hz, 1H), 6.52 (s, 2H), 6.84 (d, J=8.4 Hz, 1H), 6.99 (dd, J=2.0, 8.4 Hz, 1H), 7.32 (d, J=2.0 Hz, 1H) [0092] (Example 5) N-(5-((lR,2S)-2-(3,5-Dimethylbenzylamino)-l-hydroxypropyl)-2-hydroxyphenyl) methanesulfonamide (8) [0093] [Formula 11] [0094] Borane-pyridine complex (160 uL, 1.50 mmol) was added to a methanol solution (5 mL) of an amine (3) (131 mg, 0.50 mmol) and 3,5-dimethylbenzaldehyde (90 uL, 0.65 mmol) at 40°C and the mixture was stirred for 1.5 hours. The reaction mixture was allowed to cool to room temperature and extracted after addition of water with a mixed solvent (ethyl acetate: methanol=10:l), and the organic layer was washed with saturated aqueous sodium chloride solution. The organic layer was dried and concentrated, and the crude product obtained was purified by amine silica gel column chromatography (eluant: chloroform: methanol=7:l), to give a desired amine (8) as a white solid (62 mg, yield 33%). !H NMR (400 MHz, CD3OD) 8(ppm): 1.10 (d, J=6.4 Hz, 3H), 2.25 (s, 6H), 2.82 (m, 1H), 2.88 (s, 3H), 3.60 (d, J=12.8 Hz, 1H), 3.73 (d, J=12.8 Hz, 1H), 4.49 (d, J=6.0 Hz, 1H), 6.79 (brs, 2H), 6.84 (d, J=8.4 Hz, 1H), 6.87 (brs, 1H), 6.98 (dd, J=2.0, 8.4 Hz, 1H), 7.31 (d, J=2.0 Hz, 1H) [0095] (Example 6) N-(5-((lR,2S)-2-(3,5-Die1hoxybenzylamino)-l-hydroxypropyl)-2-hydroxyphenyl) methanesulfonamide (9) [0096]rFormula 121 [0097] Borane-pyridine complex (155 uL, 1.46 mmol) was added to a methanol solution (3.3 mL) of an amine (3) (127 mg, 0.486 mmol) and 3,5-diethoxybenzaldehyde (123 mg, 0.632 mmol) at 40°C and the mixture was stirred for 2.5 hours. The reaction mixture was allowed to cool to room temperature and extracted after addition of water with a mixed solvent (ethyl acetate: methanol=10:l), and the organic layer was washed with saturated aqueous sodium chloride solution. The organic layer was dried and concentrated, and the crude product obtained was purified by amine silica gel column chromatography (eluant: chloroform: methanol=7:l), to give a desired amine (9) as a yellow solid (114 mg, yield 54%). 'H NMR (400 MHz, CD3OD) 5(ppm): 1.14 (d, J=6.4 Hz, 3H), 1.39 (t, J=7.1 Hz, 6H), 2.88 (m, 1H), 2.93 (s, 3H), 3.63 (d, J=12.9 Hz, 1H), 3.76 (d, J=12.9 Hz, 1H), 3.99 (q, J=7.1 Hz, 4H), 4.52 (d, J=5.9 Hz, 1H), 6.35 (t, J=2.0 Hz, 1H), 6.38 (d, J=2.0 Hz, 2H), 6.88 (d, J=8.3 Hz, 1H), 7.02 (dd, J=2.0, 8.3 Hz, 1H), 7.36 (d, J=2.0 Hz, 1H) [0098] (Example 7) Evaluation of agonistic activity for human |3 adrenoreceptor 1. Test method The test was performed according to the method described in the literature of Chaudhry and Granneman (J. Pharmacol Exp. Ther., 1994, 271, p. 1253) or Michel et al. (Naunyn-Schmiedeberg's Arch. Pharmacol., 2004, 369, p. 151). Human 03 adrenoreceptor agonistic activity was evaluated by using SK-N-MC cells in the presence of a pi adrenoreceptor-selective antagonist (CGP-20712A, luM). Human 02 and pi adrenoreceptor agonistic activity was evaluated by using CHO-K1 cells in which the receptors are stably expressed. Alpha Screen cAMP Detection Kit (6760625, Perkin Elmer), which uses the change of cAMP production as indicator, was used for evaluation of the agonistic activity in all cases. Various cells were cultured in culture flasks, and the cells were separated and collected by EDTA/PBS treatment on the test day and diluted with a stimulus buffer (0.1% BSA, 500 uM IBMX, 5 mM HEPES, HBSS, pH 7.4) to a cell concentration of 10,000 cells/well. Standard solution (cAMP) or a compound solution of Example was added onto a 3 84-well plate (Optiplate New, #6007290, Perkin Elmer) in an amount of 5 uL to the final concentration (10"10 to 10"4 M) and then, 5 uL of anti-cAMP acceptor beads or a cell/Anti-cAMP acceptor beads mixture solution was added thereto, and the mixture was allowed to react at 37°C in a dark place for 30 minutes. After reaction, biotinylated-cAMP/streptavidin donor beads prepared in a lysis buffer (0.1% BSA, 0.3% Tween-20, 5 mM HEPES, pH 7.4) were added in an amount of 15 uL, and the mixture was allowed to react at room temperature in a dark place for 60 minutes, and the AlphaScreen signals (cps) from the mixture was determined with Fusion a (Packard BioScience). In data analysis, the reaction rate of the compound of each Example was first calculated, based on 100% of the maximum amount of cAMP produced by isoproterenol, and pEC50 value (negative common logarithm of 50% reaction concentration towards isoproterenol) was calculated by linear regression. When the reaction of the compound of Example did not proceed to a degree of 50% at the highest concentrations, the result was expressed by n.d. (not detected), and when the reaction of the compound of Example did not proceed to a degree of 50% in some of the tests, the average of the pEC50 values that could be calculated was used as the pEC50 value of the compound of Example. [0099] 2. Results All of the compounds of Examples 1 to 5 were shown to activate the human P3 adrenoreceptor (Table 3). [0100] In addition, the compounds of Examples 1 to 5 were all superior in selectivity to {33 adrenoreceptor and were considered to have similar properties. [0101] [0102] (Example 8) Evaluation of efficacy by using type 2 diabetes-model mice (KK/Ay mice) 1. Test method KK/Ay male mice of 5 weeks of age (CLEA Japan, Inc.) were purchased; a feeding stuff for growth CMF (Oriental Yeast) was provided since the day of arrival; and mice after growth for 3 weeks or longer were used. The compound of Example 1 was diluted to 2 mg/mL, as it is dissolved in physiological saline, and the solution was administered subcutaneously in an amount of 5 mL/kg, by using a disposable syringe (Terumo) and a 26G injection needle (Terumo). Physiological saline was administered to the mice in the vehicle group. The solution was administered once a day from the day of first administration (day 0) to day 13, and the tail vein was cut open with a knife (disposable scalpel, FEATHER) and the blood sugar was determined with a simplified blood sugar analyzer (MediSense Precision Xceed, Abotto Japan). Statistical treatment of the individual data obtained was carried out by a two-group test (unpaired t-test). [0103]; 2. Results The compound of Example 1 lowered the blood sugar statistically significantly, compared to the solvent group (Table 4). The result indicates that the compound of Example 1 is effective to type 2 diabetes. [0104] [0105] (Example 9) Evaluation of efficacy by using diabetes/obesity-model mice (DIO mice) 1. Test method C57BL/6J mice grown on a solid feeding stuff containing 60% fat (D12492, Research Diets) since 4 weeks of age, (male, Charles River Laboratories, Japan, 13 weeks of age) were purchased and mice of 16 weeks of age grown on D12492 since the day of arrival were used. C57BL/6J mice of 16 weeks of age grown on normal food since the day of arrival were used in the normal group. The compound of Example 1 was diluted to 2 mg/mL or 0.6 mg/mL, as it is dissolved in physiological saline, and the solution was administered subcutaneously in an amount of 5 mL/kg, by using a disposable syringe (Terumo) and a 26G injection needle (Terumo). Physiological saline was administered in the vehicle group. The solution was administered once a day from the day of first administration (day 0) to day 26. The .body weight was determined on day 26; the tail vein was cut open with a knife (disposable scalpel, FEATHER); and the blood sugar was determined with a simplified blood sugar analyzer (MediSense Precision Xceed, Abotto Japan). [0106] The blood was collected (approximately 70 uL) from the same site by using a heparin-treated capillary (Hematokrit Kapilaren, 75 uL, HIRSCMANN LABORGERATE) and the collected blood was centrifuged (12,000 rpm, 7 min, 4°C) in a hematocrit centrifuge (KUBOTA3100, Kubota Corp.) and the plasma was stored, as it is frozen in an Eppendorf tube, until it is used for measurement of triglyceride. The triglyceride measurement was carried out by using Triglyceride E-Test Wako (Wako Pure Chemical Industries). Four uL of the sample was added to 250 uL of the coloring liquid, after reaction at 37°C for 1 hour, and the absorbance (595 nm) of the mixture was determined by using a microplate reader (Bio-Rad, Model 680). Separately, insulin tolerance test (ITT) was performed on day 27. [0107] The mouse was left non-feeded in a fasting cage after drug administration on day 26. In the morning of the day of ITT (day 27), the fasting blood sugar was determined by a method identical with that used for blood sugar measurement on day 26. The blood sugar was measured once again in the afternoon of the same day; an insulin solution was administered intraperitoneally (0.3unit/5 mL /kg) immediately after then; and the blood sugar was measured 30, 60, 120 and 180 minutes after insulin administration since then. The insulin solution was prepared by diluting 100 unit/mL solution (Humalin R injection, Eli Lilly) with 0.1% BSA-containing physiological saline to a concentration of 0.06unit/mL. [0108] The insulin level was measured by using an insulin measurement kit (Lebis Insulin Mouse U, Shibayagi). Finally, HOMA-IR was also calculated from the values of fasting blood sugar and fasting insulin. The weight of the fat around the mouse testicles was also determined after measurement of ITT. Statistical treatment of the individual data obtained was carried out by a two-group test (unpaired t-test) or a multiplex comparison test (parametric Williams test). [0109] 2. Results (1) Efficacy in treatment of diabetes The compound of Example 1 exhibited a significant blood sugar-reducing effect even on DIO mice, which are known to be non-severe type-2 diabetes model mice (Table 5). [0110] ##p