Selenium Supplementation Affects Insulin Resistance and Serum hs-CRP in Patients with Type 2 Diabetes and Coronary Heart Disease.

To our knowledge, this study is the first indicating the effects of selenium supplementation on metabolic status of patients with type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). This study was conducted to evaluate the effects of selenium supplementation on metabolic profiles, biomarkers of inflammation, and oxidative stress of patients with T2DM and CHD. This randomized, double-blind, placebo-controlled trial was performed among 60 patients with T2DM and CHD aged 40-85 years. Participants were randomly divided into 2 groups. Group A received 200 µg selenium supplements (n=30) and group B received placebo per day (n=30) for 8 weeks. Fasting blood samples were taken at the beginning of the study and after 8-week intervention to quantify metabolic profiles. After 8 weeks, compared with the placebo, selenium supplementation resulted in a significant decrease in serum insulin levels (- 2.2±4.6 vs. + 3.6±8.4 µIU/ml, p=0.001), homeostasis model of assessment-insulin resistance (HOMA-IR) (- 0.7±1.3 vs. + 0.9±2.4, p=0.004), homeostatic model assessment-beta cell function (HOMA-B) (- 7.5±17.2 vs. + 15.1±34.5, p=0.002) and a significant increase in quantitative insulin sensitivity check index (QUICKI) (+0.01±0.03 vs. - 0.01±0.03, p=0.02). In addition, patients who received selenium supplements had a significant reduction in serum high-sensitivity C-reactive protein (hs-CRP) (- 1 372.3±2 318.8 vs. - 99.8±1 453.6 ng/ml, p=0.01) and a significant rise in plasma total antioxidant capacity (TAC) concentrations (+ 301.3±400.6 vs. - 127.2±428.0 mmol/l, p<0.001) compared with the placebo. A 200 µg/day selenium supplementation among patients with T2DM and CHD resulted in a significant decrease in insulin, HOMA-IR, HOMA-B, serum hs-CRP, and a significant increase in QUICKI score and TAC concentrations.

To study various concentrations of magnesium and aluminium on amylin hormone conformation.

Type 2 diabetes mellitus can be defined as a conformational disease since a beta cell producing protein called amylin undergoes a change in the tertiary structure followed by self-aggregation and deposition. Amylin deposition causes destruction of pancreatic beta-cells. The aim of this study was to investigate whether different concentrations of magnesium and aluminium alter amylin conformation under near-physiological circumstances. Conformational variations were monitored by fluorescent method before and after incubation by shaker incubator in 37 degrees C by LS55 spectrofluorometer instrument. This in vitro study showed that magnesium had contradictory effects on amylin folding and these effects were magnesium concentration dependent. Magnesium with concentration of 1 to 1.5 mM had inhibitory effect but in 2.5 to 3.5 microM promoted amylin misfolding significantly (p < 0.05). The obtained data also demonstrated that aluminium with concentrations of 5, 10 and 20 microM had stimulatory effects on formation of beta-amyloid sheet significantly (p < 0.05). It may be concluded that islet amyloid misfolding and cytotoxicity to beta-cells might be magnesium dose dependent in diabetic patients.