# Increased Serum Lipopolysaccharide Levels are Related to a Higher Prevalent Risk of Subclinical Hypothyroidism

## TL;DR

Higher levels of a gut bacteria component in the blood are linked to a greater risk of a thyroid condition in adults from southern China.

## Contribution

This study identifies a novel association between serum lipopolysaccharide levels and subclinical hypothyroidism in a Chinese population.

## Key findings

- Participants with higher serum lipopolysaccharide levels had a higher prevalence of subclinical hypothyroidism.
- The odds of subclinical hypothyroidism increased significantly with higher lipopolysaccharide quartiles.
- A strong dose-response relationship was observed between lipopolysaccharide levels and thyroid conditions.

## Abstract

This study aimed to assess the relationship between serum lipopolysaccharide levels and subclinical hypothyroidism in a southern Chinese adult population.

This cross-sectional community-based study included 2577 participants. Fasting venous samples were taken to examine lipopolysaccharide, thyroid hormone, thyroglobulin antibody, and thyroid peroxidase antibody levels. The population was divided into quartiles according to serum lipopolysaccharide levels. A multivariable-adjusted logistic regression model was applied to test the association between lipopolysaccharide and subclinical hypothyroidism.

Participants with increased serum levels of lipopolysaccharide had a higher prevalence of Hashimoto's thyroiditis (Q1: 10.4%, Q2: 14.3%, Q3: 17.8%, and Q4: 29.5%; p-trend < 0.001) and subclinical hypothyroidism (Q1: 2.2%, Q2: 4.7%, Q3: 7.5%, and Q4: 13.4%; p-trend < 0.001). The multivariable-adjusted odds ratios for subclinical hypothyroidism in the 2nd, 3rd, and 4th serum lipopolysaccharide quartiles were 1.979 (95% CI: 1.033–3.793), 2.867 (95% CI: 1.534–5.360), and 4.091 (95% CI: 2.198–7.613), p-trend < 0.001, respectively, compared to the 1st quartile.

Increased serum lipopolysaccharide levels were related to an increased prevalence of subclinical hypothyroidism in the southern Chinese adult population.