Thyroid-related Hormones and Hypertension Incidence in Middle-Aged and Older Hispanic/Latino Adults: The HCHS/SOL Study

Abstract

Background Thyroid-related hormones act to regulate metabolic pathways and blood pressure (BP). However, the relationship of thyroid stimulating hormone (TSH), peripheral thyroid hormones, and the role of the hypothalamic-pituitary-thyroid axis on hypertension development is not fully understood. We assessed sex-specific associations of thyroid-related hormones with BP and hypertension in Hispanic/Latino adults followed for 6 years. Methods We studied 1,789 adults, aged 45-74, free of diabetes at baseline from a subcohort of the Hispanic Community Health Study/Study of Latinos. We assessed TSH, free-thyroxine (FT4), triiodothyronine (T3), and various indicators of thyroid axis. Using multivariable linear and Poisson regression adjusted for survey design and confounding variables, we estimated a priori sex-specific associations of thyroid-related hormones with change in BP and hypertension development. Results In men and women, TSH and TSH/FT4 ratio were associated with change in diastolic-BP and T3 with change in pulse-pressure and the development of hypertension from prehypertension. . In men, 1-SD increase in TSH (Incident-Rate-Ratio(IRR)=1.42; 95%CI: 1.15,1.75) and TSH/FT4 ratio (IRR=1.20; 95%CI: 1.07,1.35) were positively associated with the development of hypertension from prehypertension while TSH/FT4 ratio (IRR=0.85; 95%CI: 0.72,1.00) was protective in women. We observed sex-specific differences in associations of T3/FT4 ratio, and indices of pituitary sensitivity to thyroid hormones with change in pulse-pressure and hypertension development. Conclusion Thyroid-related hormones are associated with sex-specific changes in BP and hypertension among Hispanic/Latino adults consistent with selected studies conducted in other populations. Mechanisms underlying associations of pituitary sensitivity to thyroid hormones with BP and hypertension development warrant further study.