Statin Therapy and Risk of Polyneuropathy in Type 2 Diabetes: A Danish Cohort Study

Abstract

OBJECTIVE Statins may reduce the risk of diabetic polyneuropathy (DPN) as a result of lipid-lowering and anti-inflammatory effects, but statins have also been associated with neurotoxicity. We examined whether statin therapy affects the risk of DPN. RESEARCH DESIGN AND METHODS We identified all Danish patients with incident type 2 diabetes during 2002–2016. New users initiated statins between 180 days before and 180 days after their first diabetes record, while prevalent users had initiated statins before that period. Patients were followed for incident DPN using validated hospital diagnosis codes, starting 180 days after their first diabetes record. Cox proportional hazard analysis was used to compute adjusted hazard ratios (aHRs) for DPN. RESULTS The study cohort comprised 59,255 (23%) new users, 75,528 (29%) prevalent users, and 124,842 (48%) nonusers; median follow-up time was 6.2 years (interquartile range 3.4–9.6). The incidence rate of DPN events per 1,000 person-years was similar in new users (4.0 [95% CI 3.8–4.2]), prevalent users (3.8 [3.6–3.9]), and nonusers (3.8 [3.7–4.0]). The aHR for DPN was 1.05 (0.98–1.11) in new users and 0.97 (0.91–1.04) in prevalent users compared with statin nonusers. New users had a slightly increased DPN risk during the first year (1.31 [1.12–1.53]), which vanished after >2 years of follow-up. Findings were similar in on-treatment and propensity score–matched analyses and with additional adjustment for pretreatment blood lipid levels. CONCLUSIONS Statin therapy is unlikely to increase or mitigate DPN risk in patients with type 2 diabetes, although a small acute risk of harm cannot be excluded.