Clark William F, Huang Shih-Han, Garg Amit X, Gallo Kerri, House Andrew A, Moist Louise, Weir Matthew A, Sontrop Jessica M
Victoria Hospital, London, Ontario, Canada.
University Hospital, London, Ontario, Canada.
Can J Kidney Health Dis. 2017 Aug 22;4:2054358117725106. doi: 10.1177/2054358117725106. eCollection 2017.
In observational studies, drinking more water associates with a slower rate of kidney function decline; whether the same is true in a randomized controlled trial is unknown.
To examine the 1-year effect of a higher vs usual water intake on estimated glomerular filtration rate (eGFR) in patients with chronic kidney disease.
Parallel-group randomized controlled trial.
Nine centers in Ontario, Canada. Enrollment and randomization occurred between May 2013 and May 2016; follow-up for the primary outcome will continue until June 2017.
Adults (n = 631) with stage 3 chronic kidney disease (eGFR 30-60 mL/min/1.73 m) and microalbuminuria.
The high water intake group was coached to increase their oral water intake by 1.0 to 1.5 L/day (depending on sex and weight), over and above usual consumed beverages, for a period of 1 year. The control group was coached to maintain their usual water intake during this time.
Participants provided 24-hour urine samples at baseline and at 6 and 12 months after randomization; urine samples were analyzed for volume, creatinine, osmolality, and the albumin-to-creatinine ratio. Blood samples were obtained at baseline and at 3- to 6-month intervals after randomization, and analyzed for creatinine, copeptin, osmolality, and electrolytes. Other measures collected included health-related quality of life, blood pressure, body mass index, and diet.
The between-group change in eGFR from baseline (prerandomization) to 12 months after randomization.
Change in plasma copeptin concentration, 24-hour urine albumin-to-creatinine ratio, measured creatinine clearance, estimated 5-year risk of kidney failure (using the 4-variable Kidney Failure Risk Equation), and health-related quality of life.
The primary analysis will follow an intention-to-treat approach. The between-group change in eGFR will be compared using linear regression. Supplementary analyses will examine alternative definitions of eGFR change, including annual percentage change, rate of decline, and rapid decline (a value <0.05 will be interpreted as statistically significant if there is concordance with the primary outcome).
This randomized controlled trial has been registered at www.clinicaltrials.gov; government identifier: NCT01766687.
在观察性研究中，多喝水与肾功能下降速度较慢有关；在随机对照试验中是否同样如此尚不清楚。
研究增加饮水量与常规饮水量相比，对慢性肾病患者估算肾小球滤过率（eGFR）的1年影响。
平行组随机对照试验。
加拿大安大略省的9个中心。2013年5月至2016年5月进行入组和随机分组；主要结局的随访将持续至2017年6月。
631名患有3期慢性肾病（eGFR为30 - 60 mL/min/1.73 m²）且有微量白蛋白尿的成年人。
高饮水量组在1年时间里，除日常饮用的饮料外，接受指导将每日口服水量增加1.0至1.5升（根据性别和体重而定）。对照组在此期间接受指导维持其常规饮水量。
参与者在基线时以及随机分组后6个月和12个月提供24小时尿液样本；对尿液样本进行体积、肌酐、渗透压以及白蛋白与肌酐比值的分析。在基线时以及随机分组后每隔3至6个月采集血样，并对肌酐、 copeptin、渗透压和电解质进行分析。收集的其他测量指标包括健康相关生活质量、血压、体重指数和饮食。
随机分组后12个月与基线（随机分组前）相比，两组间eGFR的变化。
血浆copeptin浓度的变化、24小时尿白蛋白与肌酐比值、测量的肌酐清除率、估算的5年肾衰竭风险（使用四变量肾衰竭风险方程）以及健康相关生活质量。
主要分析将采用意向性分析方法。使用线性回归比较两组间eGFR的变化。补充分析将检验eGFR变化的其他定义，包括年变化百分比、下降率和快速下降（如果与主要结局一致，p值<0.05将被解释为具有统计学意义）。
