Abstract
OBJECTIVE Genetic variation in leptin receptor (LEPR) gene has been reported to associate with insulin and glucose metabolism and adiposity in different study settings and various populations. We wanted to evaluate the association between LEPR polymorphisms, diabetes risk and body weight in Finnish subjects with impaired glucose tolerance (IGT). METHODS We investigated the associations of the three LEPR polymorphisms (Lys109Arg, Gln223Arg, 3'UTR Del/Ins) with the conversion to type 2 diabetes and the changes in body weight in 507 individuals with IGT participating in the Finnish Diabetes Prevention Study. Participants were randomized to either an intensive diet and exercise intervention group or a control group. RESULTS After 3 years, the odds ratio for the development of type 2 diabetes in individuals in the control group with the Lys109Lys genotype was 2.38-fold higher than in individuals with other genotype combinations (P=0.016). Irrespective of group individuals with the Gln223Gln genotype had higher conversion to type 2 diabetes (OR 2.01 (95% CI 1.03-3.93)) than the Arg223 allele carriers (P=0.042). The risk was more pronounced in the control group than in the intervention group. Individuals having the 3'UTR Del/Del genotype had a slightly higher body weight throughout the study than those with the insertion allele (P=0.020), although no difference in weight change was observed. CONCLUSION Two polymorphisms (Lys109Arg, Gln223Arg) in the extracellular domain of the leptin receptor predicted the conversion to type 2 diabetes in high-risk individuals with IGT. The Del/Ins polymorphism in the 3'UTR of LEPR was associated with body weight.
