Analysis of Factors Associated with Thyroid Dysfunction: A Hospital Based Study

Background Thyroid dysfunction (TD) is one of the major public health concerns in Nepal. This study intends to identify factors in association with thyroid dysfunction and its hospital based prevalence. Objective To determine hospital-based prevalence of thyroid dysfunction and to identify and analyze factors in association with thyroid dysfunction. Method A retroprospective cross-sectional study was conducted among patients attending Dhulikhel Hospital-Kathmandu University Hospital (DH,KUH) from January to December, 2015 with prospective part carried out from July to December 2015 in the patients visiting Dhulikhel hospital for health check-up and requested for Thyroid Function Tests (TFTs). Thyroid Function Tests of 1530 subjects were performed in the biochemistry laboratory and semi-structured questionnaire were introduced to 312 participants with convenient sampling method and their anthropometric measurements were taken. Chi-square test, Pearson's correlation and student-t test were used as a measure to analyze factors. Result Out of total 1530 subjects, 35.3% were having thyroid dysfunction with the prevalence of overt hyperthyroidism, subclinical hyperthyroidism, overt hypothyroidism and subclinical hypothyroidism to be 2.5%, 2.4%, 5.6% and 24.8% respectively. The distribution of thyroid dysfunction was preponderant among females and among older age. The prevalence of thyroid dysfunction was highest among Terai/Madhesi (40.0%) and lowest among Newars (28.5%) with higher fraction of hypothyroidism in each ethnic group. There were significant correlation between Thyroid Stimulating Hormone (TSH) with waist-hip ratio (p<0.05) and weight (kg) with free thyroxine (fT4) (p<0.05). Direct pesticide exposure (p<0.05) was significantly associated with hypothyroidism. The serum fT4 was significantly different (p<0.05) among vegetarian and non-vegetarian whereas TSH and free triiodothyronine (fT3) were not significantly different. Smoking, alcoholism, dietary food habits, diabetes and hypertension were not significantly associated with thyroid dysfunction. Conclusion Thyroid dysfunction was highly prevalent among participants with higher proportion of subclinical hypothyroidism. Besides, direct pesticide exposure found to be factor in association with hypothyroidism, this study could not find significance relation with other established risk factors.