Objective: To evaluate the prevalence of beta(3)-adrenergic receptor (ADRB3) Trp64Arg polymorphism and its relationship with the metabolic syndrome in severe obesity.
Design: Cross-sectional outpatients study.
Patients and methods: In 265 (100 men) severely obese non-diabetic subjects and 78 (25 men) healthy volunteers, genomic DNA was isolated from peripheral leukocytes. In obese patients, plasma concentrations of leptin, lipids, glucose and insulin, the homeostasis model assessment index and blood pressure have been measured. The Trp64Arg mutation was identified with the real-time TaqMan method.
Results: Neither genotype distribution nor allele frequency differed between the two groups. The metabolic syndrome prevalence was 59% in obese subjects, and was higher in men than in women (65 vs 55%: P=0.03). The body mass index (BMI) was related to age tertiles (beta=0.08; P<0.001; multiple linear regression) in Trp64Arg-positive obese subjects.
Conclusion: We confirm the high prevalence of the metabolic syndrome among severely obese subjects. ADRB3 polymorphism was significantly related to insulin resistance only in obese male subjects. Moreover, increased BMI was related to age in obese subjects with the ADRB3 polymorphism.