AUTHOR=Zhang Juanjuan , Hai Xinghua , Wang Siyu , Zhu Fan , Gu Yeqing , Meng Ge , Zhang Qing , Liu Li , Wu Hongmei , Zhang Shunming , Zhang Tingjing , Wang Xing , Sun Shaomei , Zhou Ming , Jia Qiyu , Song Kun , Niu Kaijun 

TITLE=Helicobacter pylori infection increase the risk of subclinical hyperthyroidism in middle-aged and elderly women independent of dietary factors: Results from the Tianjin chronic low-grade systemic inflammation and health cohort study in China

JOURNAL=Frontiers in Nutrition

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2023.1002359

DOI=10.3389/fnut.2023.1002359

ISSN=2296-861X

ABSTRACT=Background: Prospective studies on the association between Helicobacter pylori (H. pylori) infection and subclinical hyperthyroidism are limited. We therefore designed a large-scale cohort study to explore the association between H. pylori infection and the risk of subclinical hyperthyroidism in women.
Methods: This prospective cohort study investigated 2,713 participants. H. pylori infection was diagnosed with the carbon 13 breath test. Subclinical hyperthyroidism was defined as serum thyroid-stimulating hormone levels are low or undetectable but free thyroxine and tri-iodothyronine concentrations are normal. Propensity score matching (PSM) analyses and Cox proportional hazards regression models were used to estimate the association between H. pylori infection and subclinical hyperthyroidism. 
Results: 1025 PS-matched pairs of H. pylori infection women were generated after PSM. During 6-years of follow-up, the incidence rate of subclinical hyperthyroidism was 7.35/1000 person-years. After adjusting potential confounding factors (including iodine intake in food and three main dietary patterns score), the multivariable hazard ratio (HR) (95% confidence intervals) of subclinical hyperthyroidism by H. pylori infection were 2.49 (1.36, 4.56). Stratified analyses suggested a potential effect modification by age, the multivariable HR (95% confidence intervals) was 2.85 (1.45, 5.61) in age ≥ 40y participants and 0.70 (0.08, 6.00) in age < 40y participants (P for interaction =0.048).
Conclusions: Our prospective study firstly indicates that H. pylori infection is significantly associated with the risk of subclinical hyperthyroidism independent of dietary factors among Chinese women, especially in middle-aged and older individuals.