The effects of quercetin supplementation on metabolic and hormonal parameters as well as plasma concentration and gene expression of resistin in overweight or obese women with polycystic ovary syndrome.

The aim of this study was to investigate the effect of quercetin on metabolic and hormonal parameters as well as plasma concentration and gene expression of resistin in overweight or obese women with polycystic ovary syndrome (PCOS). In this randomized, double-blind, placebo-controlled trial, 78 overweight or obese women (25 ≤ BMI ≤ 40 kg/m2 , 20-40 years) with PCOS were recruited. Patients were randomized to receive 1,000 mg/day quercetin or placebo for 12 weeks. Resistin plasma concentration and gene expression in peripheral blood mononuclear cells, parameters of glucose homeostasis, circulatory testosterone, luteinizing hormone (LH), and sex hormone-binding globulin, and anthropometries were assessed at baseline and at the end of the study. Following supplementation, quercetin significantly decreased resistin concentration (2.07 ± 0.23 vs. 2.88 ± 0.40 ng/ml, p < 0.001) and mRNA level (0.64 ± 0.58 vs. 1 ± 0.56 fold change, p = 0.008), compared with placebo group. Moreover, testosterone (0.72 ± 0.15 vs. 0.76 ± 0.12 ng/ml, p = 0.001) and LH (8.05 ± 2.88 vs. 8.77 ± 1.99 mIU/ml, p = 0.035) concentrations were significantly lower in quercetin compared with placebo group. Fasting blood glucose (p < 0.001), insulin (p = 0.02), and homeostatic model assessment of insulin resistance (p = 0.009) decreased within the quercetin group; however, no significant differences were observed compared with the placebo group (p = 0.074, p = 0.226, p = 0.22, respectively). Quercetin supplementation decreased resistin plasma levels and gene expression, and testosterone and LH concentration in overweight or obese women with PCOS.

Beneficial Effects of n-3 Fatty Acids on Cardiometabolic and Inflammatory Markers in Type 2 Diabetes Mellitus: A Clinical Trial.

OBJECTIVE: To determine the effect of supplementation with n-3 polyunsaturated fatty acids (PUFAs) on circulatory resistin and monocyte chemoattractant protein 1 (MCP-1) levels in type 2 diabetes mellitus (T2DM) patients. SUBJECTS AND METHODS: This was a 10-week, placebo-controlled, double-blind, randomized trial of n-3 PUFAs (2,700 mg/day) versus placebo (soft gels containing 900 mg of edible paraffin). Forty-four T2DM patients were supplemented with n-3 PUFAs and another 44 patients received placebo (3 patients discontinued the trial). Serum resistin, MCP-1, and the lipid profile were measured before and after supplementation. The adiponectin-resistin index (1 + log10 [resistin] - log10 [adiponectin]) and atherogenic index (log10 triglyceride/high-density lipoprotein cholesterol) of plasma (an indicator of cardiovascular complications) were assessed. The independent Student t test was used to assess the differences between the supplement and placebo groups and the paired t test to analyze the before/after changes. RESULTS: In this study, n-3 PUFAs reduced serum MCP-1 levels (from 260.5 to 230.5 pg/mL; p = 0.002), but they remained unchanged in the placebo group. n-3 PUFAs could not decrease serum resistin levels. The adiponectin-resistin index was significantly reduced after supplementation with n-3 PUFAs when compared to the placebo. The atherogenic index was also significantly improved after supplementation with n-3 PUFAs (from 1.459 to 1.412; p = 0.006). CONCLUSIONS: The MCP-1 levels and lipid profile were improved after supplementation with n-3 PUFAs, but resistin serum levels were not changed. Hence, the anti-inflammatory effects of n-3 PUFAs might be mediated by targeting MCP-1.