Objective: It has been revealed that low serum magnesium (Mg) is often associated with insulin resistance (IR), cardiovascular problems, diabetes mellitus, and hypertension. Patients with polycystic ovary syndrome (PCOS) are known to have a high incidence of insulin resistance. This study was designed to determine whether women with PCOS exhibit serum magnesium deficiency and its potential association with IR.
Subjects and methods: In this cross-sectional study, 103 cases with PCOS and 103 normal women who were matched for their age and body mass index (BMI) were included. Blood samples were collected after an overnight fast and concentrations of calcium, magnesium, testosterone, dehydroepianderosterone sulfate, insulin, fasting plasma glucose (FPG), triglyceride, total cholesterol, and HDL-cholesterol were measured.
Results: The risk of PCOS for subjects with Mg deficiency was 19 times greater than those who had normal serum Mg concentrations (p ≤ 0.0001). No correlation was found between Mg and insulin sensitivity or secretion, FPG, dyslipidemias, and also androgen concentrations. After adjustment for calcium concentration the role of magnesium to predict PCOS attenuated and became non-significant (β:-1.9, p: 0.7).
Conclusion: The present study provides the first evidence showing that magnesium deficiency is not associated with IR in PCOS. According the evidences of this study, serum calcium concentration is more potent predictor of PCOS than serum Mg and only calcium, not Mg, is related to insulin resistance in PCOS.