# Arterial Stiffness and Left Ventricular Diastolic Function in Subjects with Euthyroidism

## TL;DR

This study found that higher TSH levels in euthyroid individuals are linked to increased arterial stiffness and changes in heart function.

## Contribution

The study is the first to explore the relationship between euthyroid thyroid function, arterial stiffness, and diastolic function.

## Key findings

- Higher TSH levels correlated with increased brachial-ankle pulse wave velocity (baPWV) in euthyroid subjects.
- E/A ratio was directly correlated with TSH, fT3, and baPWV in euthyroid individuals.
- Thyroperoxidase antibody was not significantly associated with the studied parameters.

## Abstract

Previous literature has suggested that the cardiovascular
risk factors associated with subclinical hypothyroidism (SCH) may be found in
subjects with euthyroidism, but research relating to increased arterial stiffness
(AS) and left ventricular (LV) diastolic dysfunction, which have been proven to
exist in patients with SCH, is limited in patients with euthyroidism. The aim of
this study was to investigate this.

A total of 249
participants with euthyroidism were divided into two groups based on their
thyroid-stimulating
hormone (TSH) levels: Group A (TSH level ranging from 0.49 to 2.5 mIU/L, n =
170) and Group B (TSH level ranging from 2.5 to 4.91 mIU/L, n = 79). The
Cardiovascular Profiling System through brachial-ankle pulse wave velocity
(baPWV) was used to assess AS, and the LV function was evaluated using
Color-Doppler-Echocardiography. The Student’s unpaired t-test and
Pearson’s χ2 test were conducted to compare the clinical parameters.
Spearman’s correlation analysis and multiple logistic regression analysis were
used to analyze the association between thyroid function, baPWV, and LV diastolic
function parameters.

Significant differences existed between
the two groups in free triiodothyronine (fT3) values and systolic blood
pressure (BP) (p < 0.05). When compared with Group A, the baPWV was
higher, the A wave increased, and the E/A ratio was lower in Group B (p
< 0.01). The multiple logistic regression analysis showed that fT3 was
associated with a higher baPWV (p < 0.001). The E/A ratio was directly
correlated with TSH, fT3, and baPWV (p < 0.05), and diastolic BP
was significantly directly correlated with the E/A ratio (p < 0.05).
Thyroperoxidase antibody was not a significant variable in the regression
analysis (p > 0.05).

An association was
found between thyroid function, baPWV, and the E/A ratio in subjects with
euthyroidism. Further study is needed to confirm these conclusions.