Abstract
Endothelial microparticles (EMPs) are related to cardiovascular disease (CVD) risk. Risk factors for CVD increase with menopause, and greater cardiorespiratory fitness is generally expected to reduce CVD risk. The effects of habitual physical activity on endothelial health may be due in part to the effect of acute exercise on circulating EMPs. This study was performed to evaluate the effect of an acute bout of exercise on CD62E(+) and CD31(+)/42b(-) EMPs in healthy fit midlife women at different menopausal stages. Healthy, active premenopausal (PRE), perimenopausal (PERI), and postmenopausal (POST) women completed a single bout of moderate-intensity treadmill exercise. Activated (CD62E(+)) and apoptotic (CD31(+)/42b(-)) EMPs were evaluated before and 30 min after exercise by using fluorescent activated cell sorting. In an exploratory analysis, these results were compared with data from low-fit peri- and postmenopausal women. Differences by group and time point were evaluated with repeated-measure ANOVAs. There was a reduction in the number of total microparticles ( P < 0.001), CD62E(+) ( P = 0.003), and CD31(+)/42b(-) ( P < 0.001) EMPs/μl plasma following acute exercise. The percentage of CD62E(+) EMPs increased with acute exercise ( P < 0.001), whereas the percentage of CD31(+)/42b(-) EMPs did not change ( P = 0.40). There was no effect of menopausal status on CD62E(+)or CD31(+)/42b(-) EMPs, or on total microparticles (all P > 0.05). The exploratory analysis revealed that low-fit women had similar changes in EMPs with acute exercise. We concluded that acute moderate-intensity exercise reduces CD62E(+)and CD31(+)/42b(-) EMPs, as well as total microparticles, in healthy midlife women. These effects occurred despite differences in menopausal status and fitness. NEW & NOTEWORTHY This study demonstrates that acute moderate-intensity exercise reduces activated and apoptotic endothelial microparticles in healthy midlife women.