Higher potency statins and the risk of new diabetes: multicentre, observational study of administrative databases

Objective — To evaluate the incremental increase in new onset diabetes from higher potency statins compared with lower potency statins when used for secondary prevention.

Design — Eight population based cohort studies and a meta-analysis. 

Setting — Six Canadian provinces and two international databases from the UK and US.

Participants — 136 966 patients aged ≥40 years newly treated with statins between 1 January 1997 and 31 March 2011.

Methods — Within each cohort of patients newly prescribed a statin after hospitalisation for a major cardiovascular event or procedure, the researchers performed as-treated, nested case-control analyses to compare diabetes incidence in users of higher potency statins with incidence in users of lower potency statins. Rate ratios of new diabetes events were estimated using conditional logistic regression on different lengths of exposure to higher potency versus lower potency statins; adjustment for confounding was achieved using high dimensional propensity scores. Meta-analytic methods were used to estimate overall effects across sites. Main outcome measure Hospitalisation for new onset diabetes, or a prescription for insulin or an oral antidiabetic drug.

Results — In the first two years of regular statin use, we observed a significant increase in the risk of new onset diabetes with higher potency statins compared with lower potency agents (rate ratio 1.15, 95% confidence interval 1.05 to 1.26). The risk increase seemed to be highest in the first four months of use (rate ratio 1.26, 1.07 to 1.47).

Conclusions — Higher potency statin use is associated with a moderate increase in the risk of new onset diabetes compared with lower potency statins in patients treated for secondary prevention of cardiovascular disease. Clinicians should consider this risk when prescribing higher potency statins in secondary prevention patients.