Effects of leptin receptor gene 3'-untranslated region polymorphism on metabolic profiles in young Japanese men.

We investigated the effects of leptin receptor gene 3'-untranslated region (3'-UTR) polymorphism on clinical and metabolic parameters in 221 young Japanese men aged 21 to 28 years. The polymerase chain reaction-restriction fragment length polymorphism method was used to identify a pentanucleotide (CTTTA) insertion in 3'-UTR of the leptin receptor gene. Body mass index, blood pressure, plasma glucose, insulin, leptin, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, free fatty acids, uric acid, apolipoprotein A-I (apoA-I), and cholesteryl-ester transfer protein levels were measured. There was only 1 homozygote and 38 heterozygotes for the 3'-UTR insertion allele among the 221 subjects. The insertion allele frequency was 0.090. Plasma HDL-cholesterol and apoA-I levels were significantly lower (p = 0.015 and p = 0.032 by Mann-Whitney U test, respectively) in homozygous or heterozygous carriers of the insertion allele than in subjects homozygous for the normal allele. There were no differences in other parameters measured. Furthermore, when the subjects were divided into three groups according to HDL-cholesterol level, the percentage of insertion allele-positive subjects was significantly lower in the highest HDL-cholesterol group (chi(2) = 8.42, p = 0.015). These findings suggest that serum HDL-cholesterol and apoA-I levels are influenced by the leptin receptor gene 3'-UTR polymorphism in young Japanese men.