Objective: To examine the contribution of the substitution of arginine for tryptophan at amino acid position 64 (Trp64Arg) of the beta 3-adrenergic receptor to body weight and weight-related factors in healthy, premenopausal women.
Subjects: Five hundred and five healthy, premenopausal women 44-50 y, body mass index (BMI) 20-40 kg/m2.
Measurements: Subjects were genotyped for the Trp64Arg substitution using restriction fragment length polymorphism (RFLP) analysis. Measurements for weight and weight-related factors (for example, weight, waist-hip ratio, lipid levels) were also taken.
Results: Two women were homozygous Arg/Arg, 75 women were heterozygous Trp/Arg, and 428 women were homozygous Trp/Trp. The frequency of the Arg substitution was 0.078. When subjects with and without the arginine substitution were compared, no significant differences were found on measures of weight or weight-related risk factors.
Conclusion: The results confirm previous studies suggesting that the Trp64Arg substitution of the beta 3-adrenergic receptor is not related to weight or weight-related phenotypes in healthy, premenopausal women.