Correlation Between Free Thyroxine Levels and Mortality in Hypertensive Patients

Area of Science:

• Endocrinology
• Cardiovascular Medicine
• Epidemiology

Background:

• Hypertension is a significant global health concern associated with increased mortality.
• Thyroid hormones, particularly free thyroxine (FT4), play a crucial role in metabolic regulation.
• The relationship between FT4 levels and mortality in hypertensive individuals remains incompletely understood.

Purpose of the Study:

• To investigate the association between free thyroxine (FT4) levels and all-cause mortality in a cohort of hypertensive patients.
• To determine if FT4 levels serve as an independent predictor of mortality in individuals with hypertension.

Main Methods:

• Analysis of data from 3365 US adults participating in the National Health and Nutrition Examination Survey (NHANES) from 2007-2012.
• Utilized weighted Cox regression, Kaplan-Meier survival analysis, and restricted cubic spline (RCS) models.
• Adjusted for covariates and performed subgroup and sensitivity analyses to ensure robustness.

Main Results:

• A positive association was observed between FT4 levels (continuous) and all-cause mortality in hypertensive patients (HR=1.08, P<.001).
• The highest quartile of FT4 was linked to significantly higher all-cause mortality risk compared to the lowest quartile (HR=1.47, P=.045).
• Kaplan-Meier curves indicated higher mortality in higher FT4 quartiles (Q3, Q4) and RCS revealed a nonlinear increasing trend.

Conclusions:

• Free thyroxine (FT4) levels are significantly associated with an increased risk of all-cause mortality in hypertensive patients.
• Elevated FT4 levels may represent a novel risk factor or marker for mortality in individuals with hypertension.
• These findings underscore the importance of considering thyroid function in the risk stratification of hypertensive patients.