A Randomized Trial of the Efficacy of Three Weight Loss Diet Interventions in Overweight/Obese with Polycystic Ovary Syndrome

Abstract

Background: Polycystic Ovary Syndrome (PCOS) is a highly prevalent, complex, heterogeneous, polygenic endocrine disorder characterized by metabolic and reproductive dysfunction that affects 8-13% of women of reproductive age worldwide. The pathogenesis of PCOS has not been fully clarified and includes genetics, obesity, and insulin resistance (IR). Oxidative stress (OS) of PCOS is independent of obesity. It can induce IR through post-insulin receptor defects, impair glucose uptake in muscle and adipose tissue, and exacerbate IR by reducing insulin secretion from pancreatic β-cells. Objective: To investigate the effects of Calorie Restricted Diet (CRD), High Protein Diet (HPD), and High Protein and High Dietary Fiber Diet (HPD+HDF) on body composition, insulin resistance, and oxidative stress in overweight/obese PCOS patients. Methods: A total of 90 overweight/obese patients with PCOS were selected to receive an 8- week medical nutrition weight loss intervention at our First Hospital of Peking University, and we randomly divided them into the CRD group (group A), the HPD group (group B), and the HPD+HDF group (group C), with 30 patients in each group. We measured their body composition, HOMA-IR index, and oxidative stress indicators. The t-test, Mann-Whitney U test, analysis of variance (ANOVA), and Kruskal-Wallis H test were used to compare the efficacy of the three methods. Results: After eight weeks, the body weights of the three groups decreased by 6.32%, 5.70% and 7.24%, respectively, and the Visceral Fat Area (VFA) values decreased by 6.8cm2, 13.4cm2 and 23.45 cm2, respectively, especially in group C (p <0.05). The lean body mass (LBM), also known as the Fat-Free Mass (FFM) values of group B and group C after weight loss, were higher than that of group A (p <0.05). After weight loss, the homeostatic model assessment of insulin resistance (HOMA-IR) index and malondialdehyde (MDA) were decreased. Superoxide dismutase (SOD) was increased in all three groups (p <0.05), and the changes in SOD and MDA in group B and group C were more significant (p <0.05). HOMA-IR index positively correlated with body mass index (BMI) (r=0.195; p <0.05); MDA positively correlated with percent of body fat (PBF) (r=0.186; p <0.05) and HOMA-IR index (r=0.422; p <0.01); SOD positively correlated with LMI/FFMI (r=0.195; p <0.05), negatively correlated with HOMA-IR index (r=-0.433; p <0.01). Conclusion: All three diets were effective in reducing the body weight of overweight/obese patients with PCOS by more than 5% within 8 weeks and could improve both insulin resistance and oxidative stress damage. Compared with CRD, HPD and HPD+HDF diets could better retain lean body mass and significantly improve oxidative stress damage.