Late last year, the American Diabetes Association (ADA) recommended the use of cholesterol-lowering medications (statins) in all patients with diabetes. ADA’s recommendation included moderate-intensity statins for people under age 40 with diabetes. Moderate-intensity statins are also recommended for those between ages 40 and 75 without risk factors for heart disease. Risk factors for heart disease include High LDL cholesterol, high blood pressure, smoking, and obesity.
Examples of moderate-intensity statins are atorvastatin ( Lipitor) at doses of 10–20 mg, rosuvastatin (Crestor) at 5–10 mg, and simvastatin ( Zocor) at 20–40 mg. Patients with diabetes who also have heart and blood vessel disease should receive high-intensity statin therapy, according to the ADA guidelines. Those between the ages of 45 and 75 who have risk factors for heart disease should also be given high-intensity statins. Examples of high intensity statins include atorvastatin at 40–80mg mg or rosuvastatin at 20–40 mg.
However, recent studies have implicated statins as a potential risk factor for increasing the onset of diabetes in the at-risk population. As such a review of some of the literature related to this topic was evaluated to investigate the impact of statins in the at-risk population. A review of findings from some studies included:
- Statins modestly increase blood glucose levels;
- And more patients who were on statin therapy were diagnosed with diabetes (27%) vs. patients who were not on statins.
A review of these studies does not mean that 27% of all patients prescribed a statin will eventually develop diabetes. Many people treated with placebo also developed diabetes. However, the findings did show that new-onset diabetes is more common in the patients who received statin treatment.
In terms of the cardiovascular benefits, people on statins had a significant drop in cardiovascular events including: a 54% lower risk for heart attack and a 48% lower risk of stroke.
Although diabetes mellitus is a serious disease, risk and benefit must be considered at the same time. In addition, ADA’s recommendation evaluates the statin dose recommendation based on the patient’s risk profile rather than on LDL level. Therefore, although the risk of increase in blood glucose is higher in patients receiving statins, this class of medicines benefits the cardiac health in people with established heart disease or risk factors for heart disease. More importantly, the strongest predictors of whether a patient will develop diabetes mellitus (regardless of whether he/she takes a statin) still includes: older age, increased weight, and higher blood glucose levels before statin use. Statins may potentially unmask diabetes mellitus that would have developed anyway based on other very important risk factors.
The effect of statins on glucose is small, and it takes combining many studies that involve thousands of patients to detect this difference in a clinical setting. The exacerbation of diabetes mellitus is relatively small, and especially so compared with the cardiovascular protection provided to those with cardiovascular risk similar to the participants in the trials.
The long-term implications of statin-induced increase in blood glucose are unknown and will become clearer as we continue to follow patients in trials of statin therapy over a longer period of time. Although it is clear that statins prevent heart disease in patients at high risk or with established cardiac disease, the use of statins in patients at lower risk (for primary prevention) is less certain.
In conclusion, as we obtain further data to define the risks and clinical implication of statin-induced diabetes, patients and their providers should continue to have a discussion of risks of heart disease and appropriateness of statin therapy. Providers should monitor blood glucose levels in patients at risk for diabetes in whom statins are used but should continue to prescribe statins when indicated to prevent future cardiovascular disease.