Bin Wang1, Weiwei He2, Qian Li1, Xi Jia1, Qiuming Yao1, Ronghua Song3, Qiu Qin3, Jin-An Zhang3. 1. Department of Endocrinology & Rheumatology, Jinshan Hospital of Fudan University, Shanghai, China. 2. Department of Endocrinology, Affiliated Hospital of Yanan University, Shanxi, China. 3. Department of Endocrinology & Rheumatology, Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China.
Abstract
BACKGROUND: Iodine status has long been regarded as an environmental determinant for thyroid dysfunction, but its relationship with thyroid autoimmunity (TAI) is still controversial. Our study aimed to elucidate the relationship between iodine status and TAI through both a population-based study and a dose-response meta-analysis of eligible epidemiological studies. METHODS: A population-based, cross-sectional study was firstly carried out, which enrolled a total of 2808 Chinese adults. Odds ratio (OR) with 95% confidence interval (95% CI) was calculated through logistic regression analysis. A dose-response meta-analysis of eligible epidemiological studies was also carried out. RESULTS: The cross-sectional study showed an U-shaped relationship between iodine intake and TAI in adults. Compared with those with more than adequate iodine status, individuals with iodine deficiency, adequate iodine status and iodine excess all had higher risk of TAI, and the adjusted ORs were 1.50 (95% CI 1.03-2.17, P = 0.032), 1.50 (95% CI 1.09-2.07, P = 0.013) and 1.68 (95% CI 1.11-2.53, P = 0.014), respectively. The dose-response meta-analysis included 22 epidemiological studies with a total of 69,987 participants and further validated the U-shaped relationship between iodine intake and TAI in adults, which proved the significantly increased risk of TAI among individuals with either iodine deficiency or iodine excess. Stratified analysis of studies with low risk of confounding bias also identified similar findings. CONCLUSION: The study suggests an U-shaped relationship between iodine intake and TAI in adults, and both iodine deficiency and iodine excess are risk factors of TAI in adults. The underlying mechanisms need to be elucidated in future studies.
BACKGROUND: Iodine status has long been regarded as an environmental determinant for thyroid dysfunction, but its relationship with thyroid autoimmunity (TAI) is still controversial. Our study aimed to elucidate the relationship between iodine status and TAI through both a population-based study and a dose-response meta-analysis of eligible epidemiological studies. METHODS: A population-based, cross-sectional study was firstly carried out, which enrolled a total of 2808 Chinese adults. Odds ratio (OR) with 95% confidence interval (95% CI) was calculated through logistic regression analysis. A dose-response meta-analysis of eligible epidemiological studies was also carried out. RESULTS: The cross-sectional study showed an U-shaped relationship between iodine intake and TAI in adults. Compared with those with more than adequate iodine status, individuals with iodine deficiency, adequate iodine status and iodine excess all had higher risk of TAI, and the adjusted ORs were 1.50 (95% CI 1.03-2.17, P = 0.032), 1.50 (95% CI 1.09-2.07, P = 0.013) and 1.68 (95% CI 1.11-2.53, P = 0.014), respectively. The dose-response meta-analysis included 22 epidemiological studies with a total of 69,987 participants and further validated the U-shaped relationship between iodine intake and TAI in adults, which proved the significantly increased risk of TAI among individuals with either iodine deficiency or iodine excess. Stratified analysis of studies with low risk of confounding bias also identified similar findings. CONCLUSION: The study suggests an U-shaped relationship between iodine intake and TAI in adults, and both iodine deficiency and iodine excess are risk factors of TAI in adults. The underlying mechanisms need to be elucidated in future studies.
Authors: K Clara Mayunga; Melany Lim-A-Po; Janniek Lubberts; Eline Stoutjesdijk; Daan J Touw; Frits A J Muskiet; D A Janneke Dijck-Brouwer Journal: Nutrients Date: 2022-09-22 Impact factor: 6.706
Authors: D A Janneke Dijck-Brouwer; Frits A J Muskiet; Richard H Verheesen; Gertjan Schaafsma; Anne Schaafsma; Jan M W Geurts Journal: Nutrients Date: 2022-09-20 Impact factor: 6.706