Statins and new-onset diabetes- In a meta-analysis of 14 randomised clinical trials with a total of 94,943 participants, during a 4-year follow-up, 4,599 developed incident diabetes. It is expected that approximately 10-11 percent of patients using statins will develop T2DM. So, how are statins causing diabetes?

Statins & diabetes: What's the link?

Through different potential mechanisms, statins can cause T2DM. They may:

• Depress insulin secretion due to changes in the calcium channel system in pancreatic beta cells
• Decrease the translocation of type 4 glucose transporter (GLUT-4) in target cells
• Reduce the downstream products of cholesterol and thereby reducing intracellular signalling

In general, the more potent the statin, the greater the chance of T2DM being developed. The most potent statins, atorvastatin and rosuvastatin, were most strongly correlated with elevated risk for T2DM in a sub-group of a meta-analysis. In comparison, low-potency statins, such as pravastatin and pitavastatin, can have a much-reduced effect on the metabolism of glucose.

Another meta-analysis showed that pravastatin increased insulin sensitivity substantially. Pitavastatin did not influence the response of hepatic or whole-body insulin as compared with placebo.

Statins- Should you prescribe?

It is important to balance the risk of new-onset diabetes against the risk of coronary events and mortality. In summary, for fear of inducing diabetes in patients at moderate to extremely high risk, high-potency statins should not be prevented.

Through comparing the effects of multiple statin therapies on glycaemic regulation in patients with T2DM, a network meta-analysis of 23 studies of 2,703 patients offers the best evidence. It was determined by HbA1c and fasting plasma glucose.

Overall, statins were correlated with an elevated HbA1c level relative to placebo. High-intensity atorvastatin, however, dramatically exacerbated glycaemic regulation effects, while moderate-intensity pitavastatin significantly decreased HbA1c and fasting blood glucose in T2DM patients.

Pitavastatin could be a safer option if only diabetes management is taken into consideration. However, it is important to understand the patient's cardiovascular risk. The greater the cardiovascular risk, despite the possible loss of glycemic regulation, the more necessary it is to use high-intensity statins.

This is the second in the series on statins. Click on the following links to read the previous article in the series.

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Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

The author, Dr. Monish S Raut is a Consultant in Cardiothoracic Vascular Anaesthesiology. His area of expertise is perioperative management and echocardiography with numerous publications in various national and international indexed journals.