The present invention provides a therapeutic agent for 
hyperlipidemia having an excellent effect of lowering the 
cholesterol and 
triglyceride level in 
blood plasma.The present invention relates to a prophylactic and / or therapeutic agent for 
hyperlipidemia, a prophylactic and / or therapeutic agent for 
obesity or 
diabetes mellitus, and a prophylactic and / or therapeutic agent for 
metabolic syndrome, each agent including a compound represented by the following formula (1):, wherein:R1 and R2, which may be identical or different, each represent a 
hydrogen atom, a 
methyl group or an 
ethyl group; R3a, R3b, R4a and R4b, which may be identical or different, each represent a 
hydrogen atom, a 
halogen atom, a nitro group, a hydroxyl group, a C1-4 
alkyl group, a 
trifluoromethyl group, a C1-4 
alkoxy group, a C1-4 alkylcarbonyloxy group, a di-C1-4 alkylamino group, a C1-4 alkylsulfonyloxy group, a C1-4 alkylsulfonyl group, a C1-4 alkylsulfinyl group, or a C1-4 alkylthio group, or R3a and R3b, or R4a and R4b are joined to represent an alkylenedioxy group; X represents an 
oxygen atom, a 
sulfur atom or N—R5 (wherein R5 represents a 
hydrogen atom, a C1-4 
alkyl group, a C1-4 alkylsulfonyl group, or a C1-4 alkyloxycarbonyl group); Y represents an 
oxygen atom, a S(O)l group (l represents a number from 0 to 2), a 
carbonyl group, a carbonylamino group, an aminocarbonyl group, a sulfonylamino group, an aminosulfonyl group, or an NH group; Z represents CH or N; n represents a number from 1 to 6; and m represents a number from 2 to 6,or a salt thereof, and a 
statin, particularly 
pitavastatin, in combination.