Higher volume of water intake is associated with lower risk of albuminuria and chronic kidney disease

Increased water intake correlated to lower vasopressin level and may benefit kidney function. However, results of previous studies were conflicted and inconclusive. We aimed to investigate the association between water intake and risk of chronic kidney disease (CKD) and albuminuria. In this cross-sectional study, the study population were adult participants of 2011–2012 National Health and Nutrition Examination Survey (NHANES) whose estimated glomerular filtration rate (eGFR) were ≥30 ml/min/1.73 m(2). Data of water intake were obtained from the NHANES 24-h dietary recall questionnaire. Participants were divided into three groups based on volume of water intake: <500 (low, n = 1589), ≥500 to <1200 (moderate, n = 1359), and ≥1200 ml/day (high, n = 1685). CKD was defined as eGFR <60 ml/min/1.73 m(2), and albuminuria as albumin–to–creatinine ratio (ACR) ≥30 mg/g. Our results showed that 377 out of 4633 participants had CKD; the prevalence inversely correlated to volume of water intake: 10.7% in low, 8.2% in moderate, and 5.6% in high intake groups (P < .001). Prevalence of albuminuria was also lower in high (9.5%) compared with moderate (12.8%) and low intake groups (14.1%), P < .001. Additionally, water intake positively correlated to eGFR and negatively correlated to urinary ACR, as well as plasma and urine osmolality. Multivariable logistic regression showed that low water intake group had higher risk of CKD (OR 1.35, 95% CI 1.01–1.82) and albuminuria when compared to high water intake group (OR 1.42, 95% CI 1.13–1.79). In conclusion, increased water intake was associated lower risk of CKD and albuminuria. Meticulous studies are needed to elucidate the underlying mechanisms.