Effect of Hypothyroidism on the Risk of Carpal Tunnel Syndrome and Electrodiagnostic Parameters.

Background: Hypothyroidism has been implicated as a risk factor for carpal tunnel syndrome (CTS). However, the effect of hypothyroidism on the risk of CTS has not been studied in large, non-selective clinic populations, and the impact of hypothyroidism on electrodiagnostic parameters remains inadequately understood.

Methods: In this retrospective study, we examined 480 patients referred for upper limb electrodiagnostic evaluation. We compared the prevalence of CTS among patients with and without hypothyroidism, adjusting for age and gender. Additionally, we compared the median nerve sensory and motor latencies and comparative latency studies (COLS) [median-to-ulnar comparison through palmar difference (Palmdiff) and ring difference studies (Ringdiff); and median-to-radial comparison through a thumb difference study (Thumbdiff)] among patients with and without hypothyroidism disease, stratified by CTS status and age groups.

Results: The crude prevalence of CTS was higher among patients with hypothyroidism (79.7%) compared to those without (61.8%) (p = 0.005). However, after adjusting for age and gender, logistic regression analysis revealed a non-significant association between hypothyroidism and CTS (adjusted odds ratio (OR): 1.71; 95% CI: 0.89-3.28, p = 0.106). CTS was more prevalent among patients with hypothyroidism under 50 years of age (OR: 2.59; 95% CI: 1.17-5.73, p = 0.018). There were no significant differences in any electrodiagnostic parameters between patients with and without hypothyroidism among CTS and non-CTS groups.

Conclusions: Hypothyroidism increased the risk of CTS among patients under 50 years of age. The electrodiagnostic parameters used for CTS diagnosis were not influenced by the presence of hypothyroidism.