Association between Thyroid Hormone Status and Peripheral Nerve Conduction Abnormalities in Adults

Abstract

Background: Thyroid dysfunction may affect peripheral nerve physiology through metabolic and structural mechanisms, producing neurological symptoms and measurable electrodiagnostic abnormalities. Comparative evidence across overt and subclinical thyroid disorders remains limited.

Objective: To assess associations between thyroid hormone status and peripheral nerve conduction abnormalities in adults.

Materials and Methods: This analytical cross-sectional study included 150 adults evaluated between January 2025 and January 2026 at the Department of Physiology, Khawaja Muhammad Safdar Medical College, Sialkot, in collaboration with the Department of Physiology, Abu Umara Medical & Dental College, Green International University, Lahore, Pakistan. Participants were categorized into five thyroid function groups. Thyroid status was classified using serum thyroid-stimulating hormone and free thyroxine, with focal median neuropathy evaluated separately. Motor and sensory nerve conduction parameters were compared, and logistic regression assessed associated factors.

Results: The cohort comprised 56 males (37.3%) and 94 females (62.7%). Nonfocal nerve conduction abnormalities occurred in 44 participants (29.3%), including 18 of 32 (56.3%) with overt hypothyroidism and seven of 48 (14.6%) euthyroid participants. Overt hypothyroidism showed slower motor conduction velocities and lower sensory amplitudes. Following adjustment for age, sex, body mass index, and diabetes, overt hypothyroidism was associated with abnormalities (adjusted odds ratio 7.28; 95% confidence interval 2.14–24.80; p=0.002). Age and diabetes were additional associated factors.

Conclusion: Overt hypothyroidism showed the strongest association with electrophysiological abnormalities. Nerve conduction assessment may help characterize peripheral nerve involvement in adults presenting with thyroid dysfunction and neurological symptoms.