Objective: This study's objective was to determine if the association between physical activity and lipids and lipoprotein subclasses in postmenopausal women varies by hormone therapy (HT) use.
Design: The cross-sectional relationship between physical activity and lipid and lipoprotein subclass relationship was examined before group randomization in 485 postmenopausal (mean age 56.9 [2.9] y) white and African American women from the Woman On the Move through Activity and Nutrition study. This study is a randomized clinical trial designed to test whether a lifestyle intervention will reduce subclinical cardiovascular disease measures.
Results: Hormone therapy users (n = 286) were significantly (P < 0.05) younger, less likely to be African American, reported higher levels of physical activity, large very low-density lipoprotein particles (VLDL-P), and medium high-density lipoprotein particles (HDL-P), had a larger mean HDL-P size, and lower levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, small HDL-P, and small VLDL-P than nonusers (n = 196). Physical activity was significantly associated with favorable lipoprotein and lipid levels, regardless of HT use. Some relationships were found to vary significantly by HT use. In nonusers, mean HDL-P and LDL particles (LDL-P) size was significantly larger (P = 0.01 and 0.05, respectively) and total and small LDL-P were significantly lower (both P = 0.02) as activity increased. These relationship were not found in HT users.
Conclusions: Physical activity was significantly related to some lipoprotein subclasses regardless of HT; however, several key lipoprotein subclasses were associated with higher levels of activity only among non-HT users.