Genetic Differences and Effects on Exercise-Induced Fat Loss in Post-Menopausal Women

Genetic Differences and Effects on Exercise-Induced Fat Loss in Post-Menopausal Women
Shelley S. Tworoger, Ph.D.
Harvard Medical School and Brigham and Women's Hospital
32ES07262 and P30ES07033

Background: Many research studies have shown that postmenopausal women with high body fat content and high body mass index (BMI) are at increased risk of developing chronic diseases such as coronary heart disease, stroke, type 2 diabetes, colo-rectal cancer, and breast cancer. Strategies to reduce body fat content and obstacles to weight reduction are important factors to identify to aid in preventing these serious illnesses. These authors have previously shown that women who participated in a year-long moderate-intensity exercise intervention reduced their BMIs and lost body fat compared to women who maintained a sedentary lifestyle. There were differences in the amount of body fat and weight reduction that might be explained by variability in genes involved in estrogen and androgen production.

Advance: To test this new hypothesis, researchers enrolled 50-75 year-old postmenopausal women in a 225 minutes/week moderate exercise program for one year. Genetic polymorphisms for two genes, CYP19 and COMT, involved in the conversion of estradiol into testosterone or less active metabolites were examined. Exercisers with the CYP19 polymorphism had a larger decrease in total fat (7 pounds lost vs. 1 pound) and percentage body fat (2.4% for 0.6%). Those women with the COMT polymorphism had a smaller decrease in percentage body fat (0.7% vs. 1.9%).

Implication: These results suggest that genetic polymorphisms in at least two genes, CYP19 and COMT, may be important for body fat regulation. Specifically, these gene forms may influence the effect of exercise on fat loss in post-menopausal women. This finding is significant because fat loss is important for lowering the risk of several chronic diseases. Knowing a person's polymorphic status for these two genes could explain why some women lose more weight than others in response to exercise and could alter the weight loss approach or warrant other interventions.

Citation: Tworoger SS, Chubak J, Aiello EJ, Yasui Y, Ulrich CM, Farin FM, Stapleton PL, Irwin ML, Potter JD, Schwartz RS, McTiernan A. The effect of CYP19 and COMT polymorphisms on exercise-induced fat loss in postmenopausal women. Obes Res. 2004 Jun;12(6):972-81.