The Effect of Thylakoid Membranes of Spinach Extract Supplementation on Atherogenic, Glycemic, and Anthropometric Indices and Renal Function in Obese PCOS Women under a Hypo-Caloric Diet: A Randomized, Double-Blind, Controlled Trial

Abstract

Background. Hyperandrogenism is a common disorder in women with polycystic ovary syndrome (PCOS) that can cause changes in body fat distribution and the amount of visceral adipose tissue. Visceral adiposity impairs insulin action, leading to insulin resistance (IR), cardiovascular disease, and renal disorders due to obesity and insulin resistance. Dietary thylakoids reduce visceral fat mass by suppressing appetite and regulating body weight. The present trial aimed to evaluate the fat distribution and renal function after thylakoid membranes of spinach supplementation along with a hypo-caloric diet. Methods. Forty-four obese women with PCOS participated in this randomized, double-blind, placebo-controlled clinical trial for 12 weeks and were allocated to receive 5 gr of thylakoid membranes of spinach extract combined with hypo-caloric diet or 5 gr placebo along with a hypo-caloric diet. Novel atherogenic and anthropometric indices including the atherogenic index of plasma (AIP), Castelli risk index I (CRI-I), Castelli risk index II (CRI-II), TyG-BMI (TyG-BMI), metabolic score for insulin resistance (METS-IR), abdominal volume index (AVI), body adiposity index (BAI), a body shape index (ABSI), and serum urea, creatinine, and total protein were assessed at the baseline and end of the intervention period. Results. Thylakoid membranes of spinach supplementation along with a calorie restriction diet showed a significant decrease in the AIP, CRI-I, II, TyG-BMI, and METS-IR ( $P$  < 0.05). AVI, BAI, and ABSI were found to reduce in the thylakoid and placebo groups ( $P$  < 0.05). However, the changes in serum urea, creatinine, and total protein did not show significant differences between the intervention and placebo groups. Conclusion. After 12-week supplementation with thylakoid membranes extracted from spinach, improvements in the value of atherogenic indices and insulin resistance surrogate markers were observed, while this intervention did not make a significant difference in the serum levels of renal function factors. This trial is registered with IRCT20140907019082N9.