Quantity-effect correlation between water intake and serum uric acid in US adults - a cross-sectional study based on NHANES data

Q: What was the main objective of the study?

To investigate the quantity-effect correlation between water intake and serum uric acid (SUA) in US adults and clarify whether the relationship is mediated by plasma osmolality.

Q: How was water intake measured and operationalized in the analysis?

Daily water intake was estimated using the average of two 24-hour dietary recalls, and the ratio of water intake to body weight (g/kg) was used as the treatment variable.

Q: What relationship did the study find between water intake/body weight and SUA?

Water intake/body weight was negatively correlated with SUA after adjustment. The association was nonlinear, showing an L-shaped curve with inflection points at 7.591 g/kg and 33.57 g/kg depending on the water measure.

Q: Did plasma osmolality mediate the effect of water intake on SUA?

Yes. Mediation analysis indicated that plasma osmolality mediated the relationship, with reported mediating effects of 9.14% and 5.84% for total plain water/body weight and total moisture/body weight, respectively.

Sep 30, 2026

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Hyperuricemia (HUA) contributes a substantial clinical and public health burden, and increased hydration is commonly recommended, yet the dose–response relationship between water intake and serum uric acid (SUA) remains unclear. A cross-sectional analysis evaluated NHANES 2009–2018 data from 15,174 US adults. Daily water intake was estimated from two 24-hour recalls, using water intake/body weight as the key variable. Multivariable regression and generalized additive models assessed associations, and mediation testing evaluated osmolality as a pathway.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages15

Reading Time38 min

AccessFree to download

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Quantity-effect correlation between water intake and serum uric acid in US adults: a cross-sectional study based on NHANES data Xiang-Liang Meng1\#, Chao Zhang1\#, Tao Liu2\#, Zhao-Kun Shi1, Yi-Xin Zhang1, Wei Hu1, Ling-Di Chang1, Jun Ding3, Xiao-Long Cao4, Li Guo5, Ke-Ying Zhang1, Wei-Jun Qin1 1Department of Urology, Xijing Hospital, Air Force Medical University, Xi’an, China; 2Department of Medical Service, The Hospital of Hebei Armed Police Corps, Shijiazhuang, China; 3Department of Urology, No. 904th Hospital of The PLA Joint Logistics Support Force, Wuxi, China; 4Department of General Practice, The Hospital of the 94857th Troop of the People’s Liberation Army of China, Wuhu, China; 5Department of Outpatient, the 986th Hospital of Air Force, Xi’an, China Contributions: (I) Conception and design: WJ Qin, KY Zhang, L Guo; (II) Administrative support: XL Meng, C Zhang, T Liu; (III) Provision of study materials or patients: ZK Shi, W Hu; (IV) Collection and assembly of data: LD Chang; (V) Data analysis and interpretation: XL Cao, YX Zhang, J Ding; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. \#These authors contributed equally to this work as co-first authors. Correspondence to: Wei-Jun Qin, MD; Ke-Ying Zhang, MD. Department of Urology, Xijing Hospital, Air Force Medical University, No. 127 Changle West Road, Xi’an 710032, China. Email: [qinwj@fmmu.edu.cn](qinwj@fmmu.edu.cn); [zhangky@fmmu.edu.cn](zhangky@fmmu.edu.cn); Li Guo, MD. Department of Outpatient, the 986th Hospital of Air Force, No. 269 Youyi East Road, Xi’an 710054, China. Email: [sderzdej@126.com](sderzdej@126.com). Background: Hyperuricemia (HUA) imposes a substantial clinical and public health burden, affecting 43 million adults in the U.S. and 170 million in China. Increased hydration is often recommended as a preventive measure for HUA, but the quantity-effect correlation between water intake and serum uric acid (SUA) is unclear. This study aimed to investigate the quantity-effect correlation between water intake and SUA. Methods: This cross-sectional study evaluated the data of 15,174 participants from the National Health and Nutritional Examination Surveys (NHANES) 2009–2018. The SUA levels (mg/dL) of all the participants were tested, and their daily water intake (g) was estimated based on the average of two 24-hour dietary recalls. To more accurately assess individual water consumption, the ratio of water intake to body weight (g/kg) was employed as a treatment variable. Multivariate linear regression models were used to evaluate the association between the two variables. Generalized additive models with smooth curve fittings were also applied. A Sobel-Goodman analysis was conducted to determine whether osmolality served as a mediator between water intake and SUA levels. Results: The final 15,174 participants had a mean age of 44.28±16.33 years (49.0% male), with SUAquartiles showing significant differences in sex, age, and lifestyle factors. The multivariate regression analyses showed that water intake/body weight was negatively correlated with SUA after adjustment for other confounders. Subgroup analyses stratified by sex showed that this negative correlation was more significant in females. Further, a nonlinear negative correlation between water intake/body weight and SUA was observed in the generalized additive model (P<0.001), showing an L-shaped curve (inflection points: 7.591 and 33.57 g/kg for total plain water consumption/body weight and total moisture intake/body weight, respectively). Plasma osmolality mediated the relationship between water intake/body weight and SUA, with mediating effects of 9.14% and 5.84% for total plain water consumption/body weight and total moisture intake/body weight, respectively. Conclusions: This study found a negative correlation between water intake/body weight and SUA, particularly in females. Moreover, the negative relationship exhibited nonlin

FAQs

What was the main objective of the study?

To investigate the quantity-effect correlation between water intake and serum uric acid (SUA) in US adults and clarify whether the relationship is mediated by plasma osmolality.

How was water intake measured and operationalized in the analysis?

Daily water intake was estimated using the average of two 24-hour dietary recalls, and the ratio of water intake to body weight (g/kg) was used as the treatment variable.

What relationship did the study find between water intake/body weight and SUA?

Water intake/body weight was negatively correlated with SUA after adjustment. The association was nonlinear, showing an L-shaped curve with inflection points at 7.591 g/kg and 33.57 g/kg depending on the water measure.

Did plasma osmolality mediate the effect of water intake on SUA?

Yes. Mediation analysis indicated that plasma osmolality mediated the relationship, with reported mediating effects of 9.14% and 5.84% for total plain water/body weight and total moisture/body weight, respectively.

Sep 30, 2026

Upload by Jiven