Selenium may increase type 2 diabetes risk

Selenium appears to reduce lipids and heighten the risk of type 2 diabetes (T2D), potentially via insulin resistance instead of pancreatic beta cell function, suggests a study.

Mendelian randomization was used to obtain unconfounded estimates of the effects of selenium on coronary artery disease (CAD), T2D, lipids, and glycaemic traits.

The authors applied genetic variants strongly correlated with blood and toenail selenium to publicly available summary statistics from large consortia genome-wide association studies of CAD (76,014 cases and 264,785 noncases), T2D (74,124 cases and 824,006 controls), lipids, and glycaemic traits. They also used inverse variance weighting, with sensitivity analyses, to combine variant specific Wald estimates.

An associated was found between genetically predicted selenium and higher T2D (odds ratio [OR], 1.27, 95 percent confidence interval [CI], 1.07–1.50; p=0.006). Evidence on an association with CAD was scant.

Genetically predicted selenium also correlated with lower low-density lipoprotein cholesterol, lower high-density lipoprotein cholesterol, higher fasting insulin, and higher homeostasis model assessment of insulin resistance. Results, however, were not robust to all sensitivity analyses.

In addition, there were no associations noted with triglycerides, fasting glucose, or homeostasis model assessment of β-cell function.

“We found little evidence of an association with CAD, although an inverse association cannot be definitively excluded,” the authors said. “The effect of selenium on these outcomes warrants further investigation.”