Thyroid diseases and risk of peripheral neuropathy in a large population-based cohort: evidence from the UK Biobank

Thyroid dysfunction has been linked to several neurological disorders, but the association between thyroid diseases and peripheral neuropathy remains insufficiently explored in large population-based cohorts. We aim to investigate the association between thyroid diseases and peripheral neuropathy.

We analyzed 498,417 complete-case participants from the UK Biobank with linked hospital diagnosis records. Thyroid diseases were defined using ICD-10 codes, including hypothyroidism, hyperthyroidism, and thyroid cancer. Peripheral neuropathy was identified using ICD-10 codes G60-G64. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

Peripheral neuropathy was identified in 6,341 participants. In the fully adjusted model including demographic, lifestyle, socioeconomic, and clinical covariates, hypothyroidism was significantly associated with peripheral neuropathy (OR 1.29, 95% CI 1.18-1.40), and hyperthyroidism showed a weaker but statistically significant association (OR 1.22, 95% CI 1.01-1.45). Thyroid cancer was not significantly associated with peripheral neuropathy (OR 1.16, 95% CI 0.66-1.89). In sensitivity analyses excluding participants with diabetes, hypothyroidism remained associated with peripheral neuropathy, whereas the association for hyperthyroidism was attenuated.

Clinically diagnosed hypothyroidism and hyperthyroidism were associated with higher odds of peripheral neuropathy in this UK Biobank-based analysis. These findings should be interpreted as associations rather than causal relationships, given the observational design and lack of thyroid hormone levels, disease severity, and treatment information.