Association of Low Zinc Concentration and Hyperleptinemia with Overweight and Insulin Resistance in Polycystic Ovary Syndrome Women

Background & Objective: It has been reported that low concentration of zinc in serum is associated with insulin resistance (IR), also appears to be a relationship between insulin and leptin. In this study the possibility of increased leptin concentration and zinc deficiency was evaluated. Their relationship with overweight and IR was also investigated in women with polycystic ovary syndrome (PCOS). Materials & Methods: In this case-control study, 104 PCOS cases and 99 healthy individuals as control were included. Blood specimens were collected from participants post overnight fasting period; zinc concentrations (spectrophotometry method), leptin (ELISA method), insulin (ECLIA method), lipid profiles and glucose were measured with enzymatic method. The homeostasis model assessment (HOMA) index determined the IR level. Results: Zinc level was 87.20 ± 11.32 μg/dl in PCOS group, and 113.68 ± 8.31μg/dl in control group. Leptin concentration was 23.06 ± 3.33 ng/mL and 19.37 ± 3.34 ng/mL, and IR was 2.37 ± 0.83 and 1.45 ± 0.74 in case and control groups, respectively (all p<0.001). Zinc had marked negative correlation with leptin, insulin, and IR (p<0.001). According to the subject, which waist circumference and body mass index (BMI) parameters were confounding factors, hyperleptinemia and zinc decrement significantly affected PCOS subjects. In contrast, only zinc decrement had an association with PCOS, after eliminating the confounding factors (OR: 0.782, p<0.001). Conclusion: Zinc reduction is more effective on PCOS than hyperleptinemia. Hyperleptinemia has association with waist circumference and BMI; it can also affect PCOS. Zinc deficiency is a more effective factor than an increase in leptin concentration in women with PCOS.