Statin Treatment Is Associated With a Higher Risk of Carpal Tunnel Syndrome, But not of Ulnar Nerve Entrapment, in Type 2 Diabetes-A Nationwide Register Study.

BACKGROUND

Individuals with diabetes (DM) are often treated with statins, which have a rare side effect: peripheral neuropathy. We aimed to study whether statin treatment affects the risk of carpal tunnel syndrome (CTS) and ulnar nerve entrapment (UNE) in type 2 DM (T2DM).

METHODS

We combined multiple national registers in Sweden to identify individuals diagnosed with CTS or UNE in specialized care 2011-2014. Individuals diagnosed with T2DM within 5 years before CTS or UNE diagnosis were included in the diabetes group. Statin treatment was defined as a prescription within 5 years before baseline. Multinominal regression analysis assessed the Relative Risk (RR) [95% confidence interval; CI] of CTS and UNE with statin treatment, using the general population as a reference.

RESULTS

In total, 4,771,118 individuals were included; 765,114 (16%) were treated with statins. There were 45,706 cases of CTS, 8,082 cases of UNE, and 244,220 individuals with T2DM. Statin treatment increased the risk of CTS (RR 1.5 [1.4-1.5]) and UNE (RR 1.4 [1.3-1.5]), adjusted for age, sex, diabetes, cardiovascular diseases, and socioeconomy. In individuals without diabetes, risks for CTS (RR 1.5 [1.4-1.5]) and UNE (RR 1.5 [1.4-1.6]) remained higher. In T2DM patients, statins increased the risk of CTS (RR 1.3 [1.2-1.4]) but not of UNE (RR 1.1 [0.9-1.3]). In all included individuals, cardiovascular diseases elevated the risk of CTS (RR 1.2 [1.1-1.2]) and UNE (RR 1.5 [1.4-1.7]).

CONCLUSION

Statin treatment is associated with a higher risk of CTS and UNE in individuals without T2DM but only of CTS in individuals with T2DM. CTS and UNE may have different aetiologies.