The women's health initiative observational study: baseline characteristics of participants and reliability of baseline measures

Abstract

The objective of this manuscript is to identify longitudinal trajectories of change in body mass index (BMI) after menopause and investigate the association of BMI trajectories with risk of diabetes and cardiovascular disease (CVD) among postmenopausal women.Using data from 54,073 participants in the Women's Health Initiative (WHI) clinical trials, we used growth mixture modeling (GMM) to develop BMI trajectories. Cox proportional hazards models were used to examine the relationship between BMI trajectories with incident diabetes and CVD. Further, we stratified by hormone therapy trial arm and time since menopause.Using GMM, we identified five BMI trajectories. We did not find evidence of substantial change in BMI over time; the trajectories were stable over the study follow-up period in this sample of postmenopausal women. Risk of diabetes and CVD increased by BMI trajectory; risk was greater for women in moderate-high, high, and very high BMI trajectories compared to those in the lowest trajectory group.Despite minimal change in BMI over the follow-up period, our results demonstrate a strong association of high BMI with diabetes and CVD. These results highlight the importance of further longitudinal research focused on adverse health effects of BMI in older women.