Objective: To investigate and compare Trp64Arg mutation of beta(3)-adrenergic receptor (beta(3)-AR) gene in simple obesity and metabolic syndrome (MS), and to correlate the mutation difference with sex, total body fat and fat distribution.
Methods: Mutation study was carried out with PCR in 295 subjects with simple obesity and 219 subjects with MS. The subjects were stratified by body mass index (BMI) as light obesity group (BMI 25 approximately 29.9 kg/m(2)) and serious obesity group (BMI >/= 30 kg/m(2)) and by mean of waist circumference (WC) as abdominal adipose tissue light depot group (WC < 104 cm in male and WC < 88 cm in female) and serious depot group (WC >/= 104 cm in male and WC >/= 88 cm in female). 175 healthy non-obese subjects were selected as controls.
Results: The frequency of Trp64Arg mutation of beta(3)-AR gene was higher in the male subjects with MS than those with simple obesity and non-obese controls (32.25%, 21.01% and 19.91%, respectively, P < 0.05) and also higher than female ones with MS (32.35% vs 23.46%, P < 0.01). It was found by further stratification that the frequency of Trp64Arg mutation of beta(3)-AR gene was higher in the male light obesity group with MS than female light obesity group with MS. The frequency is also higher than that in the male light obesity group of the obese subjects (32.83% vs 17.35%, P < 0.05 and 32.83% vs 20.41%, P < 0.05, respectively). The frequency of mutation was higher in male abdominal adipose tissue serious depot subjects with MS than those with simple obesity (35.71% vs 20.16%, P < 0.05).
Conclusion: Trp64Arg mutation of beta(3)-AR gene may be used as a genetic marker for MS in male.