Thyroid Dysfunction in Autoimmune and Nonautoimmune Thyroid Disorders: Multifactorial Study of Biochemical Profiles, Demographic Determinants, and Risk Factors

Background: Thyroid dysfunction, the most common endocrine disorder, has varied clinical presentations and public health relevance. Differentiating autoimmune thyroid disease (AITD) from non-AITD is vital, as mechanisms and management differ. While AITDs such as Hashimoto’s disease (HD) and Graves’ disease (GD) arise from immune responses, non-AITDs are shaped by demographic, metabolic, and lifestyle factors. Regional data from coastal Karnataka on biochemical, demographic, and anthropometric determinants remain scarce. Methods: A prospective cross-sectional study of 878 patients with thyroid dysfunction was conducted at a tertiary care center. Assessments included demographic, anthropometric, and lifestyle variables, as well as thyroid function tests and autoimmune markers. Biochemical parameters were analyzed by chemiluminescent immunoassay. Data were analyzed using SPSS with appropriate parametric, nonparametric, correlation, and Chi-square tests. Statistical significance was considered at P < 0.05. Results: Of 878 patients, 41 had hypofunctioning AITD (or HD) and 31 hyperfunctioning AITD (or GD), confirmed by thyroid peroxidase antibody (anti-TPO) and thyrotropin receptor antibody. Autoimmune hypothyroid patients showed higher thyroid-stimulating hormone (TSH), while autoimmune hyperthyroid patients exhibited elevated T3, T4, free thyroxine (FT4), and suppressed TSH compared to non-AITD. Body mass index correlated positively with TSH in hypothyroidism and negatively with free triiodothyronine (FT3) in hyperthyroidism. Family history, alcohol use, and rural residence were significant risk factors for hyperfunctioning AITD. Conclusion: AITD patients displayed more severe biochemical derangements than non-AITD, with distinct patterns in hypo- and hyperfunctioning states. These findings emphasize integrating autoimmune markers and population-specific risk factors into diagnostic and preventive strategies for thyroid disorders in coastal Karnataka.