The effects of exercise on cardiometabolic outcomes in women with polycystic ovary syndrome not taking the oral contraceptive pill: protocol for a systematic review and meta-analysis

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy, affecting 4–12% of reproductive-aged women. Women with PCOS often exhibit many metabolic abnormalities that are associated with an increased cardiovascular disease (CVD) risk, independent of obesity. Exercise interventions from 12 to 24 weeks have been shown to have positive effects on blood lipid profile, ovulation and insulin resistance in women with PCOS. However, no consensus on which exercise interventions are effective (i.e. duration, type of exercise, frequency), including for different phenotypes, currently exists. The aim of this systematic review and meta-analysis is to define effective types of exercise interventions to improve cardiometabolic profile, across the range of phenotypes of PCOS. Methods We will conduct electronic database searches, including randomised-controlled trials (RCT), quasi-RCT and clinical trials. Primary outcomes sought will be lipid profile, carotid-intima media thickness, fasting blood glucose, %HbA1c, blood pressure, waist circumference, waist-to-hip ratio, abdominal adiposity and inflammation markers. Secondary outcomes sought will be free and total testosterone, sex hormone binding globulin and insulin resistance. The Cochrane Risk Assessment Tool will be used to assess study quality. Data will be analysed in RevMan. Analysis of heterogeneity will be undertaken using the I2 statistic. Significant heterogeneity will be explored, and sensitivity analyses carried out as appropriate. A subgroup analysis based on androgen profile will be undertaken if data are sufficient. Discussion A large proportion of women are affected by PCOS. It is prudent to examine how CVD risk can be mitigated in this high-risk population, and this review aims to provide evidence-driven recommendations on the types of exercise interventions that are effective for this. The review will seek to provide recommendations regarding type, frequency and duration of exercise interventions to improve cardiometabolic profile in PCOS. The subgroup analysis may be able to highlight difference in intervention effects between normo-androgenic and hyper-androgenic profile. Limitations include heterogeneity across studies and a scarcity of clinical trials involving a PCOS control group not undertaking any intervention.