Increasing Water Intake in Chronic Kidney Disease: Why? Safe? Possible?

Abstract

Increased water intake may slow the progression of chronic kidney disease by lowering vasopressin levels. Prior to initiating a large randomized controlled trial on the effect of increased water intake on renal decline, we conducted a six-week pilot study to examine the safety and feasibility of asking adults with chronic kidney disease to increase their water intake. We randomly assigned 29 patients to either a hydration or a control group. The hydration group was asked to increase water intake by 1 to 1.5 l/day relative to their weight, gender, and 24 h urine osmolality, in addition to usual consumed beverages; the control group was asked to continue with usual fluid intake. After six weeks, the change in urine volume was significantly different between groups (0.9 l/day; p = 0.002) with no change in serum sodium and no serious adverse effects. Similarly, preliminary results of our large clinical trial of the same intervention (489 patients enrolled to date) demonstrated a significant separation between groups on 24 h urine volume (at 12 months the mean difference between groups was 1.2 l/day; p < 0.001) with no serious adverse effects. Serum sodium has remained stable in both groups over follow-up. To our knowledge, this trial is currently the largest of its kind to date; the significant separation between groups with respect to urine volume indicates that we will have scientifically reliable data on the effect of increased fluid intake on renal decline. The analysis of primary and secondary outcomes will be conducted at the conclusion of follow-up in July 2016.

Magnetic resonance elastography‐derived stiffness of the kidneys and its correlation with water perfusion

“…It has been shown that ADC and fractional anisotropy (FA) values decrease with loss of renal function, which suggests their correlation with fibrosis in patients with CKD. It has been hypothesized that increasing water intake could slow down the progression of CKD . Alternatively, water intake may act as a confounder in determining renal stiffness, due to an increase in perfusion pressure, and affect the diagnosis of patients with renal pathologies.…”

“…It has been hypothesized that increasing water intake could slow down the progression of CKD. 31 Alternatively, water intake may act as a confounder in determining renal stiffness, due to an increase in perfusion pressure, and affect the diagnosis of patients with renal pathologies. Here, perfusion pressure refers to the resulting increased renal tubular pressure due to a decrease in the rate of water clearance from the renal tubules, caused by filling an entire volume of bladder after water intake.…”

Influence of Physical Activity and Ambient Temperature on Hydration: The European Hydration Research Study (EHRS)

“…Furthermore, low water intake is associated with increased risk of developing hyperglycemia [ 4 ] and may increase the risk of developing type II diabetes [ 5 ]. Prospective studies measuring the impact of increased water intake on the development of these diseases are still in a preliminary phase [ 6 ].…”

Vasopressin and metabolic disorders: translation from experimental models to clinical use

“…Overall, these findings provide a rationale for intervention studies aiming to evaluate whether a reduction in AVP secretion or action could improve the metabolic status in people who are at risk of diabetes and have a high copeptin concentration/low hydration status. This may be achieved by moderate increase in water intake as it is actually tested for slowing progression of chronic kidney disease . Attention should be paid to the use of vaptan (V2 antagonist) because they induced secondarily an increase in water intake but also enhanced AVP secretion and thus V1aR‐mediated action.…”