LACK OF ASSOCIATIONS BETWEEN SERUM LEPTIN, A POLYMORPHISM IN THE GENEFOR THE BETA(3)-ADRENERGIC RECEPTOR AND GLUCOSE-TOLERANCE IN THE DUTCH POPULATION

BACKGROUND The associations between leptin levels and the prevalence o f a polymorphism in the beta(3)-adrenergic receptor were studied in a cross-sectional analysis of 600 participants in a population-based stu dy, which were stratified for glucose tolerance by an oral glucose tol erance test. METHODS In a random sample of 600 participants in the Rot terdam study, aged 55-75 years at baseline (309 men, 291 women) the re lationships were studied between the presence of Trp64 Arg mutation in the beta(3)-adrenergic receptor gene and fasting leptin, glucose and insulin (fasting and after an oral glucose load), and other components of the insulin resistance syndrome. RESULTS Mean age of the study pop ulation was 66.9 years (SD 5.7). Fasting serum leptin levels overall i n men and women were 6.1 mu g/l (SE 0.2) and 21.7 mu g/l (0.9), respec tively, (P< 0.001). These differences were independent of age, body ma ss index and waist to hip ratio. We identified 73/600 persons who were heterozygotes for the Trp64 Arg polymorphism (allelic frequency 6.1%) , but failed to find an association between the presence of this polym orphism and leptin or any measured parameter indicative for obesity, i mpaired glucose tolerance or type 2 diabetes mellitus, CONCLUSION Hete rozygosity for the Trp64Arg polymorphism of the beta(3)-adrenergic rec eptor gene is not accompanied by obesity, impaired glucose tolerance a nd type 2 diabetes mellitus in the general elderly Dutch population, a nd is also not associated with changes in circulating leptin levels.