Hypercholesterolemia as a risk factor for idiopathic carpal tunnel syndrome.

In idiopathic carpal tunnel syndrome (CTS), the median nerve is enlarged within the carpal tunnel due to intraneural connective tissue proliferation. Because hypercholesterolemia, especially increase in low-density lipoprotein (LDL), has been associated with fibrogenesis, we investigated the association of median nerve cross-sectional area and prevalence of idiopathic CTS with serum lipid measurements in middle-aged patients and controls. We found that nerve area and prevalence of CTS were correlated with serum LDL levels. Thus, high LDL levels in middle age are a risk factor for idiopathic CTS, suggesting that the LDL-correlated median nerve enlargement increases the volume of the carpal tunnel contents.