Physical activity and cardiovascular disease risk in women with polycystic ovary syndrome

Abstract

Background Polycystic ovary syndrome (PCOS) is a complex, heterogeneous endocrinopathy affecting metabolic, reproductive, and cardiovascular health in women. Evidence indicates that women with PCOS present with a cluster of cardiovascular disease (CVD) risk factors. Physical activity (PA) interventions have been shown to reduce various CVD risk factors in women with PCOS. Research also suggests that sedentary behaviours have a distinct deleterious effect on cardiometabolic health. Thus, increasing PA and reducing sedentary behaviour may be a worthwhile therapeutic target to improve cardiovascular health in women with PCOS. The programme of research presented in this thesis investigates the feasibility and acceptability of two PA interventions to improve markers of CVD risk in women with PCOS using both quantitative and qualitive methods. Methods A systematic review and meta-analysis of the effects of exercise interventions on CVD risk factors in women with PCOS provided an evidence base on which to design a supervised exercise intervention. A feasibility randomised controlled trial (RCT) of two physical activity interventions for women with PCOS was conducted. Participants were randomised to either a supervised exercise intervention, a lifestyle physical activity intervention (LPAG) aimed at reducing sedentary behaviours, or a control group, for 12 weeks. Semi-structured interviews were conducted with a purposive sample of participants from each group on completion of the RCT to explore the acceptability of the interventions, and barriers and facilitators to PA. Results The systematic review and meta-analysis demonstrated that moderate intensity aerobic exercise interventions of ≥three months in duration, with a frequency of three sessions/week, had favourable effects on CVD risk factors. These results informed the design of the RCT. Thirty-six women with PCOS were enrolled onto the feasibility RCT (12 per group). The recruitment rate was 56% and adherence rate to the exercise intervention was considered moderate at 53%. The retention rate was high at 89%, with only five participants lost to follow-up. Adherence to the LPAG was 100%. Two non-serious adverse events were reported in the exercise group, unrelated to trial procedures. For the secondary outcomes, trend data indicates a 14% reduction in oxidised LDL concentrations in the exercise group. In addition, the data indicates weight loss (kg) of 3.4% and 3.6% in the exercise group and the LPAG, respectively. Qualitative data from the interviews (n=11) indicated that the interventions were well received, but acceptability could be improved by providing social connectivity and implementing measures that encourage the adoption of long-term health-promoting behaviours. Conclusions iii The findings suggest that the procedures for recruitment, allocation, and outcome measurements were acceptable. However, adherence to the supervised exercise intervention was below an acceptable rate. The qualitative component provides valuable contextual data that will be crucial to addressing adherence for both the progression to a full-scale RCT, and community interventions for women with PCOS.