NEW ORLEANS — Lifestyle modifications in postmenopausal women attenuate the adverse effects that discontinuing hormone therapy can have on cardiovascular disease risk factors, findings from a subgroup of participants in the Women on the Move Through Activity and Nutrition (WOMAN) study show.
The study is a 5-year randomized clinical trial designed to evaluate the effects of an aggressive nonpharmacologic lifestyle intervention, including weight loss, dietary modification, and increased physical activity, on measures of subclinical cardiovascular disease. In all, 508 women were randomized to the lifestyle intervention group or to a health education control group for the study, and 240 of these women—the subgroup that was studied in the current analysis—represent those who were taking hormone therapy (HT) at baseline.
Of these 240, 130 discontinued HT within 18 months of study entry, and in these 130 discontinuers, total and LDL cholesterol levels had significantly increased at 18-month follow-up, compared with levels in the 110 participants who remained on HT at 18 months. Stratification by randomized group assignment (the lifestyle modification “intervention” group, or the health education “control” group) in these women—which enabled a comparison between HT continuers and discontinuers in each of the two groups—showed that lifestyle modifications successfully counteract these increases, Kelley K. Pettee, Ph.D., reported in a poster at the annual meeting of the American College of Sports Medicine, and subsequently in the American Journal of Preventive Medicine (Am. J. Prev. Med. 2007;32:483–9).
At 18 months, the 70 HT discontinuers in the intervention group had a mean 4-mg/dL increase in total cholesterol and a mean 7-mg/dL increase in LDL cholesterol, which was not statistically different from the mean 5-mg/dL increase in both total and LDL cholesterol in the 64 HT continuers in the intervention group. However, the 60 HT discontinuers in the control group experienced a mean 22-mg/dL increase in both total and LDL cholesterol, compared with a mean 3-mg/dL increase in total cholesterol and a mean 5-mg/dL increase in LDL cholesterol in the 46 HT continuers in the control group, noted Dr. Pettee, who conducted the research while she was a doctoral candidate at the University of Pittsburgh, but who is currently at Arizona State University, Mesa.
Furthermore, when all 134 women in the intervention group were compared with all 106 in the control group, those in the intervention group experienced significantly greater overall decreases in weight, body mass index, and waist circumference, as well as significantly improved fat intake and increased leisure physical activity, providing further evidence of the benefits of the lifestyle modifications, she reported. (See box.)
WOMAN study participants had a waist circumference of at least 80 cm, and a body mass index (kg/m
The median duration of HT use prior to study entry did not differ between the continuers and discontinuers, but the groups differed in that continuers were slightly younger and had higher total cholesterol and lower insulin levels. The groups did not differ significantly in regard to anthropometric measures, leisure physical activity, fat intake, or cholesterol, triglyceride, and glucose levels, and they were also similar in regard to education, race, and smoking status.
Those randomized to the control group received a core educational series of six health-related lectures offered during the first year and quarterly thereafter, and those in the lifestyle intervention group worked closely with a team of nutritionists, exercise physiologists, and psychologists who developed individualized diet and exercise programs designed to reduce weight and waist circumference. Those in the intervention group participated in at least 150 minutes per week of moderate-intensity physical activity, and had a caloric intake of 1,300–1,500 calories per day of low total fat and low saturated-fat foods.
Previous studies have shown that lifestyle interventions have a beneficial effect on cardiovascular disease risk factors, but did not account for concurrent changes in HT status, which is “an issue that has become relevant in the post-WHI [Women's Health Initiative] era,” Dr. Pettee wrote, referring to the fact that many women discontinued HT following publication of WHI findings that linked HT use with an increased risk of cancer and other health problems.
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