Serum phospholipid response to aerobic exercise training in pre- and postmenopausal women

Abstract

This study examined the effects of exercise training on serum phospholipids in pre-and postmenopausal women. Thirty-six volunteers, 19 premenopausal and 16 postmenopausal women, completed a 12 week aerobic training program. A strict selection criteria excluded volunteers who had diabetes, heart disease, used oral contraceptives or estrogen supplements, were excessively obese, used tobacco or alcohol products, or engaged in regular exercise. Subjects exercised four times a week by walking with the intensity advancing from 836.8 kilojoules/session at 60% of initial individual V02max to 1,464.4 kilojoules/session at 75% Of V02max. Height, weight, body fat, lung residual volume, and V02max were measured prior to and following the training. Diet was controlled as subjects followed a prescribed diet for a two week period prior to and following the exercise training. Blood samples were taken both prior to and after exercise training to analyze serum cholesterol and serum phospholipids. Serum phospholipid analysis included total phospholipids, sphingomyelin (SPM), phosphatidylcholine (PC), and SPM to PC ratio. Post-exercise blood samples were taken at least 48 hours after the last training session. Neither group showed significant changes in total cholesterol as a result of the exercise training. Aerobic training resulted in an 18% increase in VO2max for premenopausal women and a 13 % increase in V02max for postmenopausal women. Serum phospholipid levels did not change significantly in either the pre-or postmenopausal groups following exercise training, but were significantly lower in the premenopausal group compared to the postmenopausal group. The ratio of SPM to PC was significantly lower in premenopausal women compared to postmenopausal women prior to exercise training, but was not significantly different following exercise training. These results suggest that menopause significantly alters the serum phospholipid levels which could be associated with the greater risk of heart disease found in postmenopausal women. They also suggest that exercise training may have an impact on SPM to PC ratio which may influence the risk factors for heart disease.