A new Lancet study brought statins’ diabetes risks back into the headlines, showing that statins do indeed drive significant increases in new diabetes diagnoses, while arguing that statins’ cardiovascular benefits still far outweigh their diabetes risks.
Researchers from the Cholesterol Treatment Trialists’ Collaboration analyzed 19 RCTs comparing statins versus a placebo (n= 124k, 21% w/ diabetes, 4.3yr median follow up) and four RCTs comparing low and high-intensity statin therapies (n= 31k, 17% w/ diabetes, 4.9yr median follow up), finding that…
- Low- or moderate-intensity statin therapy drove a 10% relative increase in new-onset diabetes versus placebo (2,420 of 39,179 vs. 2,214 of 39,266 participants).
- High-intensity statin therapy drove a 36% relative increase in new-onset diabetes versus placebo (1,221 of 9,935 vs. 905 of 9,859 participants).
Those are concerning numbers at first glance, however further analysis revealed that future diabetes diagnoses were largely influenced by baseline HbA1c levels and follow-up testing.
- Among participants without baseline diabetes, mean glucose increased by just 0.04 mmol/L in statin-takers, while HbA1c increased by 0.06% in patients receiving low/moderate statins and by 0.08% in patients receiving high-intensity statins.
- Among patients with baseline glycaemia, 62% of new new-onset diabetes cases involved participants who were already in the top quartile of glycaemic levels.
- The rate of new-onset diabetes was mainly dependent on how many participants actually received follow-up HbA1c tests (so more testing drove more positives…), and the analysis’ high-intensity statin trials were much more likely to include follow-up HbA1c tests (explaining higher diabetes rates w/ high-intensity statins).
These results revived statin diabetes debates on MedTwitter, with one extremely prominent physician highlighting statins’ diabetes risks, and others suggesting that this study adds evidence that statins’ diabetes risks aren’t “clinically relevant” since statins are proven to reduce mortality.
The Takeaway
Although the link between statins and diabetes is widely known, this analysis shows that the majority of new diabetes diagnoses are happening in statin-takers who already had “baseline glycaemic markers that are close to the diagnostic threshold for diabetes.”
That’s worth keeping in mind for the many borderline diabetic patients who are taking statins (or could be soon), but it’s also worth keeping in mind the authors’ primary message that statins’ absolute benefits “greatly outweigh any excess risks of diabetes.”
