AUTHOR=Zhu Yongjian , Liu Xiaozhuan , Li Ning , Cui Lingling , Zhang Xiaofeng , Liu Xinxin , Yu Kailun , Chen Yao , Wan Zhongxiao , Yu Zengli 

TITLE=Association Between Iron Status and Risk of Chronic Kidney Disease in Chinese Adults

JOURNAL=Frontiers in Medicine

VOLUME=6

YEAR=2020

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2019.00303

DOI=10.3389/fmed.2019.00303

ISSN=2296-858X

ABSTRACT=<p><bold>Background:</bold> Even though it is well-known that iron deficiency is the result of chronic kidney disease (CKD), whether iron will affect kidney function and disease in the general population is not clear. We thus conducted a nationwide cross-sectional study using data from the China Health and Nutrition Survey (CHNS) to assess the relationship of iron status with estimated glomerular filtration rate (eGFR) and CKD among general adults.</p><p><bold>Methods:</bold> A total of 8,339 adults from the China Health and Nutrition Survey in the wave of 2009 were included to assess the association between iron status and eGFR/CKD. Serum ferritin (SF), transferrin, soluble transferrin receptor (sTfR), and hemoglobin (Hb) were measured. The relationship of iron status and eGFR was evaluated by using multi-variable linear regression model. The effect of iron status on the odds of CKD was calculated by logistic regression model.</p><p><bold>Results:</bold> For the association between iron status and eGFR, every 100 μg/L increase in SF was correlated with 0.26 ml/min per 1.73 m<sup>2</sup> (95% CI: 0.08–0.44) decrease in eGFR, and every 5 mg/L increase in sTfR was associated with a decrease of 6.00 ml/min per 1.73 m<sup>2</sup> (95% CI: 3.79–8.21) in eGFR. There were no significant associations between Hb or transferrin with eGFR. For the association between iron status and CKD, every 5 g/L increase in sTfR was associated with an odds ratio of 3.72 (95% CI: 2.16–6.13) for CKD. The concentrations of Hb were associated with the odds of CKD in a U-shaped manner, with the lowest risk in the Hb range of 136–141 g/L. There was a positive correlation between SF concentration and CKD prevalence but not in a dose–response manner. The odds of CKD for participants in the highest tertile increased by 28% (98% CI: 1–63%) compared with those in the lowest tertile.</p><p><bold>Conclusion:</bold> The concentration of SF and sTfR was positively correlated with the odds of CKD, and Hb was associated with the odds of CKD in a U-shaped manner. Further large prospective researches are warranted to confirm these findings.</p>