title: Weight loss and proteinuria: systematic review of clinical trials and comparative cohorts.
abstract: BACKGROUND
  Obesity is a risk factor for the progression of chronic kidney disease (CKD). The impact of weight loss on proteinuria and renal function is less clear. We aimed to determine the effect of intentional weight loss on proteinuria and kidney function.
  
  
  METHODS
  Three bibliographic databases including Medline, Cochrane and SCUPOS as well as reference list of articles were searched. We included randomized and non-randomized controlled trials as well as single-arm trials published in English through May 2009 which examined urinary protein among obese or overweight adults before and after weight loss interventions including dietary restriction, exercise, anti-obesity medications and bariatric surgery. Study characteristics and methodological quality of trials were assessed.
  
  
  RESULTS
  Five hundred twenty-two subjects from five controlled and eight uncontrolled trials were included. Weight loss interventions were associated with decreased proteinuria and microalbuminuria by 1.7 g [95% confidence interval (95% CI), 0.7 to 2.6 g] and 14 mg (95% CI, 11 to 17 mg), respectively (P < 0.05). Meta-regression showed that, independent of decline in mean arterial pressure, each 1 kg weight loss was associated with 110 mg (95% CI, 60 to 160 mg, P < 0.001) decrease in proteinuria and 1.1 mg (95% CI, 0.5 to 2.4 mg, P = 0.011) decrease in microalbuminuria, respectively. The decrease was observed across different designs and methods of weight loss. Only bariatric surgery resulted in a significant decrease in creatinine clearance.
  
  
  CONCLUSIONS
  Weight loss is associated with decreased proteinuria and microalbuminuria. There were no data evaluating the durability of this decrease or the effect of weight loss on CKD progression.
authors: St. Joseph's Hospital, HealthEast Care System, University of Minnesota School of Public Health, Minneapolis, MN, USA. afshi001@umn.edu
authors: Farsad
authors: F
authors: Afshinnia
authors: Timothy J
authors: TJ
authors: Wilt
authors: Sue
authors: S
authors: Duval
authors: Abbas
authors: A
authors: Esmaeili
authors: Hassan N
authors: HN
authors: Ibrahim
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000503:physiopathology*; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D016208:Databases, Factual; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology*; D009765:Obesity / Q000503:physiopathology*; D011507:Proteinuria / Q000503:physiopathology*; D015431:Weight Loss