New onset diabetes mellitus induced by statins: current evidence

The hydroxyl-methyl-glutaryl-coenzyme-A (HMG-CoA) reductase inhibitors of statin action are very effective and safe drugs, and they are widely used for the treatment of hyperlipidemia and the prevention of primary and secondary cardiovascular diseases (CVDs). However, recent meta-analyses of previous studies done with statins have shown that these drugs could induce new onset diabetes mellitus (NODM), especially in subjects prone to diabetes: obese, females, older age, Asian descent, and those with pre-diabetes or the metabolic syndrome. Several meta-analyses of randomized, controlled trials with statins and population-based studies of subjects taking statins have shown different incidence of NODM ranging from 28% in the JUPITER study to 43% in the UK clinical practice cohort. The exact cause of statin-induced NODM is not clearly known and several pathophysiologic mechanisms have been proposed, which include modification of the lipoprotein particle size, inhibition of HMG-CoA reductase, decreased expression of GLUT 4, and decreased adiponectin and ubiquinone levels, including others, which all lead to either increase in insulin resistance or decrease in insulin secretion. Based on the current evidence, the use of statins should not be withheld from subjects at high cardiovascular risk, even if they are prone to NODM, because their benefits outweigh their risks. However, in persons prone to the development of NODM, vigilance is required and periodic measurements of plasma glucose or HbA1c should be performed. If NODM develops, statin treatment should not be stopped, but a switch to administration of a more favorable statin, administration of statin on alternate days, or reduction of the dose should be considered, or antidiabetic therapy added.