A Hospital-Based Case-Control Study on the Association Between Vitiligo and Thyroid Dysfunction

Abstract

Introduction: Vitiligo is a chronic autoimmune disorder characterized by depigmentation and is known to be associated with thyroid dysfunction. However, data regarding this association in Nepal are limited. This study aims to ascertain the prevalence of thyroid dysfunction among patients with vitiligo and to evaluate its correlation with clinical parameters.

Methods: This hospital-based case-control study involved the enrolment of 100 clinically diagnosed vitiligo patients and 100 frequency-matched controls at Nepalgunj Medical College and Teaching Hospital, Kohalpur, Nepal. Serum thyroid-stimulating hormone (TSH) levels were quantified using chemiluminescent immunoassay (CLIA). Thyroid dysfunction was characterized by TSH levels of less than or equal to 0.39 mIU/L, indicating hyperthyroidism, or more than or equal to 50 mIU/L, indicating hypothyroidism. Statistical analyses were conducted using the Mann-Whitney U test, chi-square test (Yates-corrected) or Fisher’s exact test, and odds ratio (OR) with a 95% confidence interval (CI).

​Results: The prevalence of thyroid dysfunction was significantly higher among cases compared to controls (26.0% vs. 5.0%; OR = 6.68, 95% CI 2.45–18.22, p < 0.001). Hypothyroidism was observed in 20.0% of cases as opposed to 5.0% of controls (OR = 4.75, 95% CI 1.71–13.23; p = 0.003), while hyperthyroidism was present in 6.0% of cases and absent in controls (p = 0.029). Female patients exhibited a significantly higher incidence of thyroid dysfunction compared to male patients (38.3% vs. 7.5%; OR = 7.67, 95% CI 2.12–27.76, p = 0.001). Additionally, the extent of disease, as measured by body surface area, was significantly correlated with thyroid dysfunction (p = 0.031).

Conclusions: Vitiligo is significantly correlated with thyroid dysfunction, particularly hypothyroidism, with a notably elevated risk observed in female patients and those exhibiting moderate disease severity. It is recommended that routine TSH screening be conducted for all individuals diagnosed with vitiligo.

Keywords: Case-control study, hypothyroidism, Nepal, thyroid dysfunction, vitiligo