A Randomized Controlled Trial of a Lifestyle Intervention With Longitudinal Follow-up on Ovarian Dysmorphology in Women With Polycystic Ovary Syndrome

Maryam Kazemi; Roger A. Pierson; Laura E. McBreairty; Philip D. Chilibeck; Gordon A. Zello; Donna R. Chizen


Clin Endocrinol. 2020;92(6):525-535. 

In This Article

Abstract and Introduction


Objective: Effects of lifestyle modification on reproductive function in polycystic ovary syndrome (PCOS) remain poorly elucidated. We compared the effects of a pulse-based diet (lentils, beans, split peas and chickpeas) with Therapeutic Lifestyle Changes (TLC) diet on ultrasonographic markers of ovarian morphology, hyperandrogenism and menstrual irregularity in PCOS.

Design: Randomized controlled trial.

Patients: Women with PCOS (18–35 years).

Measurements: Thirty women randomized to the pulse-based and 31 to TLC groups completed a 16-week intervention without energy restriction. Groups performed aerobic exercise (minimum of 5 days/wk; 45 minutes/d) and received health counselling (monthly) and longitudinal follow-up. Follicle numbers per ovary (FNPO, 2–9 mm), ovarian volume (OV), free androgen index (FAI) and menstrual cycle length were measured pre- and postintervention.

Results: Follicle numbers per ovary (mean change ± SD, −10 ± 15), OV (−2.7 ± 4.8 mL), FAI (−3 ± 2) and menstrual cycle length (−13 ± 47 days) decreased over time in both groups (All: P < .01), without group-by-time interactions (All: P ≥ .13). Attrition rate was 33.7% and comparable between groups (P = .94). Adherence to diet intervention negatively correlated with changes in FNPO (r=−0.54), OV (r=−0.35) and FAI (r = −.29) in pooled groups (All: P ≤ .04). Groups maintained reduced OV, FNPO, FAI and menstrual cycles 6 months postintervention; however, decreased FNPO and FAI at 16 weeks tended to revert to baseline levels 12 months postintervention in both groups (All: P ≤ .05).

Conclusions: Both interventions improved ovarian dysmorphology, hyperandrogenism and menstrual irregularity in PCOS, and no diet appeared to be superior at improving reproductive outcomes. Our observations highlight the importance of longitudinal surveillance for sustainable adherence to newly adopted healthy lifestyle behaviours and reproductive health in PCOS (ClinicalTrials.gov identifier, NCT01288638).


The recent International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome (PCOS) recommended lifestyle interventions (dietary, exercise, behaviour or combined) as the first-line therapy to mediate favourable metabolic outcomes in women with PCOS.[1] The short-term benefits of weight loss on hyperandrogenism and menstrual cyclicity were demonstrated in overweight or obese women with PCOS in previous randomized controlled trials (RCT);[2–6] however, current reports lack unique dietary recommendations that do not specifically target weight loss for improving reproductive health. Successful and sustainable weight loss remains a challenge, is less attainable in the long term and may not be generalized to all women with PCOS variants across body mass index (BMI) classes. Women with PCOS perceive an inevitability for weight gain and adverse health outcomes and exhibit poor adherence to weight loss programmes corresponding with the duration of the intervention.[2,3,7–9] Together, little can be concluded regarding the existence of a favourable dietary composition to improve reproductive health in PCOS.[1] The longitudinal impacts of lifestyle change programmes in women with PCOS also remain poorly elucidated.[1]

The relationship between lifestyle modification and ovarian function has biological plausibility, yet remains unknown.[7] Ultrasonography is a noninvasive and reproducible tool to diagnose and monitor ovulatory disorders.[10] Ultrasonographic markers of ovarian morphology, including ovarian volume (OV) and follicle numbers per ovary (FNPO), objectively reflect aberrations in folliculogenesis and the magnitude of reproductive and metabolic sequelae in PCOS.[11–13] Identification of abnormal ovarian function using high-resolution ultrasonography could be useful to enable visualization of the biological responses to lifestyle change and a valuable means for the lifelong surveillance of women with PCOS in the light of reproducible and reliable measurements.[10,14]

Women with PCOS exhibit cardiometabolic aberrations, including dyslipidaemia and dysglycaemia.[15] Ovarian dysfunction and hyperandrogenism may be related to insulin resistance (IR) and hyperinsulinaemia.[15] In a multidimensional RCT without prescribed energy restriction,[16] we demonstrated the benefits of a pulse-based diet over the National Cholesterol Education Program Therapeutic Lifestyle Changes (TLC) diet[17] on lipid profiles and on reducing insulin response to an oral glucose tolerance test in women with PCOS. Dietary pulses are nonoilseed leguminous crops harvested for the dry grain and include chickpeas, lentils, dry beans and split peas.[18] Adherence to a low-glycaemic index pulse-based diet has been associated with improved glucoregulatory status and decreased risk of cardiovascular disease and type 2 diabetes.[18] The TLC diet is a standardized healthy diet designed to reduce hypercholesterolaemia.[17] In the present primary outcome analysis of the trial, we compared the effects of a pulse-based with the TLC diet on ovarian function, assessed by ultrasonographic markers of ovarian morphology, and hyperandrogenism and menstrual irregularity in PCOS, where both diet groups also engaged in aerobic exercise training and health counselling as a standard of care. We hypothesized that a nutritionally balanced pulse-based diet would be more effective than the TLC diet at improving reproductive health outcomes in women with PCOS after 16 weeks of a comprehensive lifestyle change intervention. Additionally, we evaluated the long-term effects of the intervention on reproductive outcomes.