Statin use and risk of first-time psoriasis diagnosis

Statins have been suggested as a potential treatment for psoriasis because of their anti-inflammatory properties. However, evidence on the benefits of statins is scarce.

We sought to study the association between use of statins or other lipid-lowering agents and the risk of developing psoriasis.

We conducted a case-control analysis using the United Kingdom-based General Practice Research Database. We identified patients with an incident psoriasis diagnosis between 1994 and 2005 and matched one control subject to each patient on age, sex, general practice, calendar time, and years of history in the database. We estimated odds ratios (ORs) with 95% confidence intervals (CIs), stratified exposure by timing and duration, and adjusted the ORs for potential confounders.

We identified 36,702 incident psoriasis cases and the same number of matched controls. Adjusted ORs for current use (last prescription <30 days before index date) of 1 to 4, 5 to 19, or greater than or equal to 20 prescriptions for statins, as compared with nonuse, were 0.60 (95% CI 0.45-0.80), 1.00 (95% CI 0.84-1.18), and 1.08 (95% CI 0.92-1.28), respectively. The ORs for recent and past use (last prescription 30-89 days and ≥90 days ago, respectively) were around 1, except for past use of 1 to 4 prescriptions (OR 1.39; 95% CI 1.09-1.78).

Potential of residual confounding as a result of retrospective study design is a limitation.

This large case-control study does not provide evidence for an altered risk of developing psoriasis in association with long-term use of statins. The reduced psoriasis risk for current short-term statin users is interesting, but whether the association is indeed causal needs further investigation.