Are the use of statins associated with an increase in diabetes?
A 2010 paper in the Lancet  reports:
“FINDINGS: We identified 13 statin trials with 91 140 participants, of whom 4278 (2226 assigned statins and 2052 assigned control treatment) developed diabetes during a mean of 4 years. Statin therapy was associated with a 9% increased risk for incident diabetes (odds ratio [OR] 1.09; 95% CI 1.02-1.17), with little heterogeneity (I(2)=11%) between trials. Meta-regression showed that risk of development of diabetes with statins was highest in trials with older participants, but neither baseline body-mass index nor change in LDL-cholesterol concentrations accounted for residual variation in risk. Treatment of 255 (95% CI 150-852) patients with statins for 4 years resulted in one extra case of diabetes.
INTERPRETATION: Statin therapy is associated with a slightly increased risk of development of diabetes, but the risk is low both in absolute terms and when compared with the reduction in coronary events. Clinical practice in patients with moderate or high cardiovascular risk or existing cardiovascular disease should not change.”
This article was reviewed by the National Prescribing Centre , which reported:
“The results of this meta-analysis show that patients taking statins were at slightly increased risk of diabetes compared with those not taking statins, and this risk seemed higher in older patients. The results only show that statins were associated with an increased risk of diabetes, not that they caused this (although this is a possibility) and the association may be due to residual confounding factors. Also, we don’t know from this study if any increase risk of developing diabetes resulted in a detrimental effect on patient-oriented outcomes, i.e. did them developing diabetes prevent them living longer or better?
Whatever the cause, in absolute terms, the increased risk of diabetes is small, especially in relation to the reduction in cardiovascular events seen with statins. In this meta-analysis, one additional case of diabetes was seen per 255 patients taking statins for four years. The authors calculated that, using data from the Cholesterol Treatment Trialists (CTT) meta-analysis of statin trials in 71,370 non-diabetic patients, statins are associated with a reduction in major coronary events of 5.4 events per 255 patients treated for four years (this is compared with control therapy for a 1mmol/L reduction in LDL-cholesterol).
In view of the evidence for benefit with statins, the authors argue that the small excess risk of incident diabetes is favourably balanced by cardiovascular benefit. Therefore, these results should not change clinical decision making in patients for whom statins are indicated. NICE guidance on lipid modification states that statins should be offered to people with clinical evidence of CVD, or a 20% or greater 10-year risk of developing this; and this guidance remains appropriate. For patients at lower cardiovascular risk or in patient groups in which cardiovascular benefit has not been proven, the potentially raised risk of diabetes should be taken into account if statin therapy is considered.
The authors recommend that the development of diabetes should be specified as a secondary endpoint in future large statin trials. They also suggest that screening for diabetes might be useful in patients taking statins, particularly older patients, and this would seem to be sensible advice.”