Serum Thyroid Peroxidase Antibody Level and Incident Hypertension in Iranian Men: A Suggestion for the Role of Thyroid Autoimmunity

Background: Dysfunction of the thyroid gland has profound effects on the cardiovascular system. Objective: We aimed to explore the relation of serum thyroid peroxidase antibody (TPO-Ab), as a marker of thyroid autoimmunity with incident hypertension among a euthyroid population. Methods: A total of 3681 participants (1647 men) entered the study. Multivariate Cox proportional hazard models were conducted to estimate the association between TPO-Ab and incident hypertension. Results: The mean age (standard deviation) of the participants was 37.5 (12.8) years. During a median follow-up of 12.2 years, 511 men and 519 women developed hypertension. The multivariable hazard ratios (HRs) and related 95% confidence intervals (CIs) of 1-unit increase in natural logarithm (ln) of TPO-Ab for incident hypertension were 1.09 (1.00-1.19), 1.03 (0.97-1.10), and 1.05 (1.00-1.11) for men, women, and total population, respectively. Moreover, considering the TPO-Ab status as a categorical variable (i.e. TPO-Ab positive or TPO-Ab negative), the multivariate-adjusted HRs (95% CIs) of TPO-Ab positivity for incident hypertension, were 1.33 (0.95-1.85), 1.12 (0.86-1.45) and 1.19 (0.97- 1.46) for men, women, and total population, respectively. Conclusion: Elevated serum TPO-Ab level can contribute to the development of hypertension among euthyroid men during a long follow-up; suggesting a role for thyroid autoimmunity.