¹Department of Environmental Medicine, Shimane Medical, University, Izumo City, Shimane, Japan

Correspondence: Dr K Shiwaku, Department of Environmental Medicine, Shimane Medical University, 89-1 Enya-cho, Izumo City, Shimane 693-8501, Japan. E-mail: shiwaku@shimane-med.ac.jp

Received 12 July 2002; Revised 8 April 2003; Accepted 11 April 2003.

Abstract

OBJECTIVE: Trp64Arg mutation in the ₃-adrenergic receptor ( ₃AR) gene is relatively common in Japanese people. However, it has not been clear whether persons with Trp64Arg mutation in the ₃AR gene tend to have obesity and difficulty in losing weight even with a restricted diet and exercise. We investigated the response of body weight and metabolic factors to behavioral intervention in Japanese women with Trp64Arg mutation in the ₃AR gene.

DESIGN: A 3-month behavioral intervention study using a combination of diet and exercise programs.

SUBJECTS: A total of 76 perimenopausal women with no clinical symptoms (age: 54.77.7 y, body mass index (BMI): 21.0–33.0 kg/m²).

MEASUREMENTS: Anthropometric measurements (weight, height, body fat, waist circumference, hip circumference, skin fold, resting energy expenditure and blood pressure) and metabolic measurements (serum levels of cholesterol, triglyceride, phospholipid, nonesterified fatty acid, glucose, insulin and leptin) and determination of the ₃AR genotype by polymerase chain reaction followed by BstNI digestion.

RESULTS: At the baseline of BMI, body weight, body fat, waist circumference, hip circumference, the arm skin fold, resting energy expenditure, or blood lipid and glucose profiles, there was no significant difference in participants with/without mutation of the ₃AR gene. The intervention yielded a body weight reduction in 69 and 48%, and induced a significant difference in weight loss (-0.74 and -0.01 kg) for women with wild-type and Trp64Arg mutation, respectively. Significant differences of anthropometric parameters were found in body weight, BMI, waist and hip circumferences and blood pressure of wild type by the intervention. However, women with Trp64Arg mutation did not show significant changes in these anthropometric parameters, except for hip circumference. A significant difference was found in high-density lipoprotein cholesterol (HDL-C) and in the low-density lipoprotein cholesterol/HDL-C ratio in both genotypes.

CONCLUSION: The results of the present study suggest that the Trp64Arg mutation of the ₃AR gene is associated with difficulty in losing weight through behavioral intervention, although it is not related to obesity-related phenotypes and resting energy expenditure before the intervention.