Purpose: To determine the role of moderate-to-vigorous physical activity (MVPA) and sedentary behavior in flow-mediated dilation (FMD) and glucose metabolism during late pregnancy.
Methods: Seventy normotensive, euglycemic pregnant women (31.6 ± 2.9 yr) in their third trimester (28-39 wk) were recruited. After a fasted blood sample; FMD was measured (brachial artery Doppler ultrasonography, normalized for the shear stimulus [area under the curve]). Anterograde and retrograde shear rate were estimated. Physical activity (MVPA) and sedentary behavior were assessed via accelerometry for seven consecutive days (Actigraph wGT3X-BT). We categorized the women as active (>150 min·wk) or inactive (<150 min·wk) according to their accelerometry data. Data were corrected for age and gestational age.
Results: On average, women were sedentary 67.1% ± 8.2% of their waking hours. Active pregnant women (>150 min·wk MVPA, n = 32) engaged in 266.7 ± 99.3 min·wk MVPA, whereas inactive pregnant women (<150 min·wk MVPA, n = 38) engaged in 76.1 ± 42.5 min·wk MVPA. The FMD response (normalized to the magnitude of shear stress stimulus) was greater in active compared with inactive pregnant women (6.5 ± 4.4 a.u. vs 3.9 ± 3.5 a.u.; F = 4.619; P = 0.005). The MVPA in active pregnant women was inversely correlated with insulin concentrations (r = -0.556; P = 0.03). In inactive pregnant women, higher amounts of sedentary behavior were associated with lower amounts of retrograde shear rate (r = 0.504; P = 0.02), retrograde blood flow (r = 0.499; P = 0.02), and retrograde velocity (r = 0.508; P = 0.02) during baseline, but not correlated with the FMD response.
Conclusions: Engaging in MVPA during pregnancy is associated with improved FMD and a lower insulin concentration. Sedentary behavior was not associated with FMD responses.