Zinc supplementation ameliorates type 2 diabetes markers through the enhancement of total antioxidant capacity in overweight patients.

BACKGROUND: Evidence show that the recommended dose of zinc may not be sufficient for controlling pathological conditions such as type 2 diabetes mellitus (T2DM). AIM: This study aimed to evaluate the effects of zinc supplementation on the oxidative status in overweight T2DM. In addition, the routine glycaemic parameters were determined and compared in zinc-treated and placebo groups. METHODS: In this randomised, double-blind, placebo-controlled trial, 70 patients with T2DM were selected. They were divided into two groups for supplementation of 50 mg zinc gluconate or placebo (zinc group, n=35; placebo group, n=35) per day for 8 weeks. Blood samples were collected from all the individuals in the zinc group and controls for analysis. RESULTS: The results showed that zinc supplementation to patients with T2DM for 8 weeks significantly inhibited serum levels of lipid peroxidation (25%), nitrotyrosine (30%) and total oxidant status levels (25%, p<0.05). Nevertheless, the total antioxidant capacity was significantly elevated (16%) following zinc intake by patients with T2DM. CONCLUSIONS: These data, together with our previous report, may suggest that the control in the glycaemic condition in overweight patients with T2DM is correlated with the antioxidative/oxidative balance following intake of 50 mg zinc supplementation for 8 weeks. Under these circumstances, the clinical and glycaemic indices, including fasting blood glucose, insulin, haemoglobin A1c and homeostasis model of assessment-insulin resistance, were controlled. TRIAL REGISTRATION NUMBER: IRCT2015083102.

The relationship between thyroid function tests and sleep quality: cross-sectional study.

INTRODUCTION: The relationship between sleep and hormones have long been recognized. Studies indicated that sleep quality is one of the major modulatory effects on the endocrine system. In this study, we aimed to assess the serum concentration of thyroid hormones in individuals who suffered from low quality sleep. MATERIAL AND METHODS: Based on the Pittsburgh Sleep Quality Index and ISMA Stress questionnaire, we divided 83 participants into two groups. Forty-one individuals with low quality sleep group and 42 with good quality sleep group, all from the male students of a medical school in Tehran, Iran, participated in this descriptive and cross-sectional study. Then, serum levels of thyroid hormones including free T3, free T4, and TSH were assessed and compared between two groups. RESULTS: There were a significant increase in serum levels of FT4 (p=0.01) and TSH (p=0.02). There were also meaningful correlations between sleep score and stress score (p=0.008) as well as stress score and FT4 (p=0.03) in the case group. CONCLUSIONS: The current study showed that thyroid function tests (T4 and TSH) significantly rose in the poor sleep condition. We also found correlations between sleep score, stress score, and FT4 in the poor sleep condition group that suggest low sleep quality can affect thyroid hormones.

Effects of zinc supplementation on superoxide dismutase activity and gene expression, and metabolic parameters in overweight type 2 diabetes patients: A randomized, double-blind, controlled trial.

OBJECTIVE: Despite the current guidelines for the management of type 2 diabetes mellitus (T2DM), patients still struggle with the hyperglycemia consequences. Imbalance in zinc homeostasis, in particular, renders diabetic patients more susceptible to the damages of oxidative stress. This study aimed to evaluate the effects of zinc supplementation on the superoxide dismutase gene expression and enzyme activity in overweight individuals with T2DM. Additionally, biochemical parameters, such as fasting blood glucose (FBG), insulin, glycated hemoglobin (HbA1c), homeostasis model of assessment-insulin resistance (HOMA-IR), serum levels of zinc and lipid profile, were assessed. METHODS: In this randomized, double-blind, placebo-controlled trial, 70 overweight (BMI > 25) T2DM patients were selected based on the inclusion criteria. They were divided into two groups for supplementation of daily 50 mg zinc gluconate or placebo for 8 weeks. Blood samples were collected from all the individuals in the zinc group and controls for analysis. RESULTS: The results showed that, in comparison with the control group, zinc supplementation increased both gene expression and enzyme activity of SOD (p < 0.01) as well as the levels of insulin (p = 0.02) among the patients in the zinc group. Moreover, there was a meaningful reduction in the levels of FBG, HbA1c and HOMA-IR value (p < 0.001), triglycerides and total cholesterol (p < 0.05) after the zinc treatment. CONCLUSIONS: Taken together, the current study suggests that daily supplementation with 50 mg zinc gluconate could be a useful approach for the management of overweight T2DM. CLINICAL TRIAL REGISTRATION: IRCT2015083102.

Micronutrient status (calcium, zinc, vitamins D and E) in patients with medullary thyroid carcinoma: A cross-sectional study.

OBJECTIVE: The aim of this study was to evaluate the micronutrient status of Iranian patients with medullary thyroid carcinoma (MTC) and to analyze potential relationships with respect to MTC risk. METHODS: This was a cross-sectional study (Tehran Thyroid Cancer Survey 2015-2016). We measured and compared preoperative serum calcium, zinc, and vitamins D and E in patients with MTC and healthy controls. Forty cases with MTC and 40 (age-, sex-, and body mass index-matched) healthy controls voluntarily participated in the project. RESULTS: Serum calcium, zinc, and vitamin D and E concentrations were lower in the patients with cancer (PCa < 0.001, PZn = 0.01, PD = 0.056, PE = 0.002) than in the healthy controls. We found that serum calcium remarkably associated with enhanced risk for thyroid cancer (odds ratio [OR], 6.5; P = 0.001). Likewise, serum vitamin E was linked to the risk for cancer (OR, 1.31; P = 0.056). Moreover, serum zinc was correlated with vitamin E and calcium (r = +0.23; P = 0.04 and r = +0.25, P = 0.03; respectively). We also observed a correlation between calcium and vitamin E (r = +0.27; P = 0.02). CONCLUSIONS: A multiple-micronutrient decrease was confirmed in patients with MTC. A low serum calcium level was a potent risk factor for MTC. Findings from the present study suggest that dietary intake and/or supplementation of micronutrients, especially calcium and vitamin E, may be beneficial in reducing the risk for thyroid cancer.