Applied nutritional investigationAssociation of Gln223 Arg polymorphism of the leptin receptor gene with indicators of energy expenditure in obese children

ObjectiveGln223 Arg polymorphism of the leptin receptor (LEPR) gene is one of the most frequently examined polymorphisms of this gene and has been suggested to be associated with energy expenditure (EE). The aim of the present study was to investigate the association of this variant on indicators of EE-resting metabolic rate (RMR), postabsorptive and postprandial respiratory quotient (RQ), and food-induced thermogenesis (FIT)-in obese children.MethodsThe study included 486 genotyped children (obese, n = 355). RMR was measured by indirect calorimetry for 45 min. Subsequent to test-food consumption, FIT was measured in a subsample of obese children (n = 121, body mass index 31.9 kg/m2 (mean ± SD 5.1).ResultsObese children with the Gln223 Gln genotype showed a significantly lower post-absorptive and postprandial RQ (P = 0.0055 versus P = 0.0002, adjusted for age, sex, and lean body mass) than did groups of children with Gln223 Arg and Arg223 Arg genotypes. No significant differences were observed in FIT and RMR among the carriers and non-carriers of the 223 Arg allele.ConclusionThe significantly lower post-absorptive and postprandial RQ in the group of Gln223 Gln genotype children indicates that the fat oxidation of these children maybe increased before and subsequent to food consumption, which can be important in the planning of diet of these children.