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

Abstract

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.

Effectiveness and safety of selenium supplementation for type 2 diabetes mellitus in adults: a systematic review of randomised controlled trials

“…Three RCTs evaluated the effect of Se supplementation compared to placebo on the change in LDL level. No difference was noted after 8 weeks ( n = 60; Se 0.2 mg day −1 ) and 12 weeks (two RCTs; n = 120; Se 0.2 mg day −1 ) of study.…”

“…A higher MD for HDL in favour of the Se group was found for only one RCT ( n = 60; Se 0.2 mg day −1 ) after a 12‐week intervention (calculations based on available data) . However, no effect of Se supplementation was reported in another two RCTs after 8 weeks ( n = 60; Se 0.2 mg day −1 ) and 12 weeks ( n = 60; Se 0.2 mg day −1 ) of study.…”

“… (53.2 to 54.9 μg day −1 ). Apart from one trial , where financial support from industry was declared, all other studies were supported by grants .…”

The Effect of Selenium Supplementation on Glucose Homeostasis and the Expression of Genes Related to Glucose Metabolism

“…After six weeks of Se supplementation (200 µg/day), significant decrease in serum insulin levels and HOMA-IR values was observed [25]. Another study which was conducted in 60 subjects of both sexes (20 males and 40 females) diagnosed with T2DM and coronary heart disease also showed beneficial effects of Se supplementation (200 µg/day for eight weeks) in terms of decreased insulin, HOMA-IR, HOMA-B parameters, and increased QUICKI [26]. On the contrary, only one RCT, conducted in patients with T2DM ( n = 60, including 34 males and 26 females), indicated that three months of Se supplementation (200 µg/day) led to the increased FPG levels [27].…”

Serum Selenium Status in Patients with Type 2 Diabetes and Control Group

“…Diabetes associated oxidative stress is responsible for secondary complications of diabetes (González de Vega, Fernández-Sánchez, Fernández, Álvarez Menéndez, & Sanz-Medel, 2016;Kahya, Nazıroğlu, & Övey, 2016) so antioxidant supplements such as selenium seems to be highly desirable for the treatment of this disease and its complications (Kahya, Naziroğlu, & Çiğ, 2015;Feng et al, 2015). However, other studies have shown that there is a positive correlation between serum level of selenium and diabetes incidence (Laclaustra, Navas-Acien, Stranges, M. Ordovas, & Guallar, 2009;Stranges et al, 2007;Steinbrenner, Speckmann, Pinto, & Sies, 2011;Lu et al, 2016;Thompson et al, 2016;Farrokhian et al, 2016;Rotter et al, 2015;Bleys, Navas-Acien, & Guallar ,2007;Mueller, Mueller, Wolf, & Pallauf ,2009). …”