Treatment with statins and involvement of the peripheral nervous system: results of a prospective clinical and neurophysiological follow-up.

AIMS To study the pathological changes in neurophysiological examination of lower-limb peripheral nerves in patients with long-term statin treatment. METHODS Forty-two patients (23 males, 19 females, mean age 51.9 and 52.3 years) with a definitive diagnosis of combined hyperlipidemia were studied. Other metabolic disorders or chronic ethanol abuse were excluded. Initial examinations included laboratory and neurophysiological measures (peroneal and tibial nerves: MNCV, CMAP, F-wave mean latency; superficial peroneal and sural nerve: SNCV, SNAP). Subsequently, treatment with simvastatin 20mg daily was initiated. Patients were followed for 24 months with examinations at 1, 6, 12 and 24 months after statin treatment initiation. RESULTS None of the patients reported subjective symptoms typical for polyneuropathy. In laboratory findings, there was no elevation of muscle enzymes. Nevertheless, electrophysiological examination of lower-limb peripheral nerves demonstrated statistically significant prolongation of F-wave mean latency on peroneal and tibial nerves (p < 0.0001, paired t-test). A control group of 50 patients with combined hyperlipidemia but no statin treatment showed no changes over the same time interval. The study demonstrated that long-term CONCLUSIONS The study demonstrated that long-term treatment with statins might cause a clinically silent but still electrophysiologically definite damage to peripheral nerves.