Longitudinal Weight Gain and Lifestyle Factors in Women With and Without Polycystic Ovary Syndrome

Background: While women with polycystic ovary syndrome (PCOS) have a higher prevalence of overweight/obesity and increased weight gain than women without PCOS, the association of lifestyle behaviours with weight change is not known. Methods: We used data from the 1973–78 cohort of the Australian Longitudinal Study on Women’s Health for longitudinal analysis over 19 years (N=14127 at survey 1). Linear mixed-effects models were used to examine weight change and its association with diet, physical activity and sitting time, adjusted for sociodemographic, psychological factors and health care utilisation. Results: Women with PCOS gained more weight annually (0.27 kg/year, 95% CI 0.14, 0.40; P<0.001) and over 19 years (15.3 kg 95% CI 10.9, 19.7 Vs. 10.8 kg 95% CI 5.5, 16.2) than women without PCOS. There was a three-way interaction between energy intake (0.31 kg, 95% CI 0.004, 0.61; P=0.047), glycaemic index (0.44 kg, 95% CI 0.13, 0.74; P=0.005), sitting time (0.55 kg 95% CI 0.002, 1.10; P=0.049), physical activity (-0.37 kg, 95% CI -0.69, -0.05; P=0.022) and PCOS and time. While women with PCOS had higher weight gain than those without PCOS overall, this difference was greater for women with PCOS with higher energy intake, glycaemic index and longer sitting time and those not meeting PA guidelines. Conclusions: Women with PCOS had a higher rate of weight gain than those without PCOS with those with unhealthy lifestyle behaviours having the greatest weight gain. Women with PCOS may be biologically predisposed to weight gain when experiencing adverse lifestyle factors. This reinforces the contribution of lifestyle factors to weight change and the importance of early lifestyle intervention in PCOS.