EFFECTS OF ENDURANCE EXERCISE AND HORMONE REPLACEMENT THERAPY ON SERUM-LIPIDS IN OLDER WOMEN

OBJECTIVE: To determine the effects of 11 months of exercise training and hormone replacement therapy (HRT), alone or in combination, on ser um lipids and lipoproteins, in postmenopausal women. DESIGN: Controlle d, prospective, 11-month clinical trial. Healthy postmenopausal women (n = 71, age range 60-72 yrs) were assigned to four groups in a 2 x 2 design (control, exercise, HRT, exercise + HRT). SETTING: Large, midwe stern urban community; subjects were recruited from the community-at-l arge. The exercise program was conducted at a university exercise faci lity. INTERVENTIONS: HRT consisted of conjugated estrogens at 0.625 mg /day and trimonthly medroxyprogesterone acetate 5 mg/day for 13 days. Exercise consisted of 2 months of low intensity exercise followed by 9 months of vigorous exercise for 45 min/day, 3 or more days/week, at 6 5-85% of maximal heart rate. MEASUREMENTS: Maximal aerobic power (VO2 max), resting blood pressure, body composition, serum lipids and lipop roteins, and dietary intake at baseline and after 11 months. MAIN RESU LTS: At the end of 11 months, subjects in the exercise group had decre ased total cholesterol (TC; P < .01) and LDL-cholesterol (LDL-C; P < . 05), but there was no change in HDL-cholesterol (HDL-C) or triglycerid es. Women in the HRT group had decreased LDL-C (P < .001) and increase d HDL-C (P < .01) and triglycerides (P < .01), but there was no change in TC. Exercise+HRT subjects had decreased TC (P < .05) and LDL-C (P < .001), and increased HDL-C (P < .001); exercise prevented the HRT-re lated increase in triglycerides. CONCLUSIONS: Endurance exercise train ing and HRT have independent and complimentary effects on serum lipid profiles in healthy postmenopausal women. Such effects are likely to r educe the risk of cardiovascular morbidity in this population.