Statin therapy and risk of polyneuropathy in type 2 diabetes: A Danish cohort study
Statins may reduce the risk of diabetic polyneuropathy (DPN) due to lipid-lowering and anti-inflammatory effects, but statins have also been associated with neurotoxicity. We examined whether statin therapy impacts the risk of DPN.
RESEARCH DESIGN AND METHODS
We identified all Danish incident type 2 diabetes patients 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 first diabetes record. Cox proportional hazard analysis was used to compute adjusted hazard ratios (aHRs) for DPN.
The study cohort comprised 59,255 (23%) new users, 75,528 (29%) prevalent users, and 124,842 (48%) non-users; median follow-up time was 6.2 years (interquartile range 3.4-9.6). The incidence rate of DPN events per 1000 person-years was similar in new users (4.0 [95% CI 3.8-4.2]), prevalent users (3.8 [3.6-3.9]) and non-users (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 non-users. New users had a slightly increased DPN risk during the first year (aHR 1.31 [1.12-1.53]) which vanished after more than 2 years of follow-up. Findings were similar in on-treatment and propensity score-matched analyses, and with additional adjustment for pre-treatment blood lipid levels.
Statin therapy is unlikely to increase or mitigate DPN risk in type 2 diabetes patients, although a small acute risk of harm cannot be excluded.