Objectives: The role of the leptin receptor (LEPR) gene Gln223Arg polymorphism on the metabolic and body composition changes in response to overfeeding was studied.
Subjects: Twelve pairs of male monozygotic twins ate a 4.2 MJ day-1 energy surplus, 6 days week-1, during a period of 100 days.
Results: Overfeeding induced a significantly greater increase in glucose (P = 0.001 for percentage change) and insulin (P = 0.038) areas under the curve during oral glucose tolerance tests (OGTTs) in the GlnGln (n = 10) than in the GlnArg/ArgArg (n = 14) subjects. In addition, the GlnGln genotype was associated with a greater increase in plasma levels of leptin (P = 0.037) and total triglycerides (P = 0.003), as well as a greater decrease in high-density lipoprotein cholesterol (P = 0.010), than for the combined GlnArg/ArgArg genotypes. Body composition changes were not different between the genotypes.
Conclusions: We conclude that the GlnGln subjects of the LEPR gene polymorphism are more susceptible to metabolic abnormalities when they are exposed to long-term positive energy balance. These findings provide new information on the genetic basis of individual differences in response to chronically elevated food intake.