Women with polycystic ovary syndrome gained more weight annually than those without PCOS, and some lifestyle factors had a greater impact on weight gain with PCOS, according to study data.

“To our knowledge, this is the first time the contribution of extrinsic factors (including lifestyle and psychological factors and health care utilization) to weight gain has been examined in women with and without PCOS,” Lisa J. Moran, BSc (Hons), BND, PhD, APD, associate professor at the Monash Centre for Health Research and Implementation at Monash University School of Public Health in Melbourne, Australia, and colleagues wrote in a study published in Human Reproduction. “The prevalence of self-reported PCOS in this study was 8.7%, which is consistent with previous studies reporting 8.7% based on the National Institutes of Health diagnostic criteria. Using data from a large community-based longitudinal study, we found that women with PCOS had a 0.26 kg higher rate of annual weight gain and a 4.62 kg higher weight gain over 19 years than women without PCOS, even after adjusting for lifestyle factors.”

Researchers analyzed data from participants in the Australian Longitudinal Study on Women’s Health who were born from 1973 to 1978 and completed seven surveys from 1996 to 2015. Sociodemographic data, dietary intake, sitting time, physical activity, depression, anxiety and stress were self-reported. Participants reported whether they had a PCOS diagnosis in the last four surveys.

There were 7,180 women who completed all seven surveys, of which 8.7% reported having PCOS. Women with PCOS had a mean body weight in the first survey of 67.4 kg vs. 62.3 kg in those without PCOS. At 19 years, mean body weight increased to 82.9 kg for women with PCOS and 73.4 kg for those without PCOS.

In adjusted analysis, women with PCOS gained 4.6 kg more than those without PCOS at 19 years (P < .0001). The annual rate of weight increase was higher for women with PCOS vs. without PCOS (0.81 kg vs. 0.55 kg; P < .0001).

Each megajoule increase in energy intake (beta = 0.55; 95% CI, 0.41-0.68; P < .0001) and each hour increase of sitting time (beta = 0.24; 95% CI, 0.17-0.31; P < .0001) were associated with total weight gain for women with and without PCOS. Stress was the only psychological factor associated with weight change (beta = 0.97; 95% CI, 0.55-1.39; P < .0001). Weight gain was lower for each gram of fiber intake per day (beta = –0.08; 95% CI, –0.12 to –0.03; P = .001) and for women meeting physical activity guidelines compared with those not meeting guidelines (beta = –0.99; 95% CI, –1.33 to –0.65; P < .0001).

Three-way interaction testing between lifestyle and psychological factors, health care engagement and PCOS status and time was conducted to explore differences in weight-gain factors for women with PCOS and without PCOS. The rate of weight gain for women with PCOS was greatest for those with a higher energy intake (P = .006), greater consumption of foods with higher glycemic index (P = .025), sitting time of more than 10 hours per day (P = .041) and not meeting physical activity guidelines (P = .021).

“Our finding here of higher weight gain in women with PCOS and differentially greater impact of adverse lifestyle on weight gain in PCOS are important,” the researchers wrote. “These findings suggest that women with PCOS are biologically predisposed to weight gain overall, and that this is exacerbated disproportionately by adverse lifestyle factors. This aligns with patient experience from women with PCOS who reported perceived greater susceptibility for weight gain.”

The researchers said a greater focus on lifestyle interventions for preventing weight gain in women with PCOS is needed.