Longitudinal changes in HDL-cholesterol concentration are associated with different risk factors in primiparous and nulliparous young women: The NHLBI Growth and Health Study (NGHS)

Abstract

Previous studies report that first pregnancy is associated with persistent decreases in HDL-cholesterol (HDL-C) concentrations. This study evaluated factors associated with declines in HDL-C concentration in parous and nulliparous young women. This study leverages data from African-American and white women from the NHLBI Growth and Health Study. Parity-related changes in lipids, BMI and percent body fat were assessed longitudinally. A subset of primiparous and nulliparous women with paired lipid measurements were analyzed regarding changes in HDL-C concentrations. Among 870 women in longitudinal analyses, African-American women had higher parity (p<0.0001), with baseline measurements of each parity group being similar. HDL-C concentration decreased significantly and remained lower after the first pregnancy, while BMI and percent body fat increased with increasing parity. In the subset of 401 women, HDL-C concentration decreased among primiparous women (-4.81±0.93mg/dl), with no overall change in nulliparous (p=0.003). In both groups, greater HDL-C concentration declines were independently associated with higher initial HDL-C concentration and greater increases in BMI (both p<0.0001). Among primiparous women, younger delivery age (p=0.0001) and birth control use (p=0.004) were associated with greater HDL-C concentration decline. Nulliparous white women's HDL-C concentration increased over time, with no change in African-American women (p=0.008); no racial difference was seen in primiparous women. Persistent decreases in HDL-C concentration were associated with the first pregnancy, and were greater with higher initial HDL-C concentration. Racial differences in HDL-C concentration emerged over time in nulliparous women, but not primiparous women. Potential impacts of these findings on women's long-term cardiometabolic health should be evaluated.