title: Effect of weight loss after Roux-en-Y gastric bypass, on renal function and blood pressure in morbidly obese patients.
abstract: BACKGROUND
  Morbid obesity (MO) is associated with increased renal plasma flow (RPL) and glomerular filtration rate (GFR). This type of obesity usually does not respond to medical treatment, with bariatric surgery being the current treatment of choice. The present study aimed to evaluate whether weight loss may reverse the glomerular hyperfiltration of MO patients.
  
  
  METHODS
  This was a retrospective study of 140 patients submitted to Roux-en-Y gastric bypass (31.5% men, mean body mass index 46.17 +/- 5). Renal glomerular function and anthropometric and biochemical parameters were studied in patients before and 8 months after the surgery. GFR was determined by 24-hour urine samples.
  
  
  RESULTS
  In the obese group, GFR before surgery was 148.7 +/- 35.2 ml/min. After the weight loss, GFR decreased to 113.8 +/- 31.7 ml/min (p<0.0001). Homeostasis model assessment-insulin resistance and glycosylated hemoglobin values were higher in MO with hyperfiltration. Weight loss was associated with reduction in blood pressure and GFR. It was found that the variation in systolic and diastolic blood pressure was a predictor of change in GFR.
  
  
  CONCLUSIONS
  This study shows that obesity-related glomerular hyperfiltration ameliorates after weight loss. The improvement in hyperfiltration may prevent the development.
authors.affiliation: Division of Clinical and Surgical Treatment of Obesity, ABC Medicine School, São Paulo, Brazil. aryserpa@terra.com.br
authors.forename: Ary
authors.initials: A
authors.lastname: Serpa Neto
authors.forename: Felipe Martin
authors.initials: FM
authors.lastname: Bianco Rossi
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Dal Moro Amarante
authors.forename: Nara
authors.initials: N
authors.lastname: Alves Buriti
authors.forename: Gabriel
authors.initials: G
authors.lastname: Cunha Barbosa Saheb
authors.forename: Marçal
authors.initials: M
authors.lastname: Rossi
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D015390:Gastric Bypass; D005919:Glomerular Filtration Rate / Q000502:physiology; D005923:Glomerulosclerosis, Focal Segmental / Q000150:complications / Q000628:therapy; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000628:therapy; D007668:Kidney / Q000098:blood supply / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D015431:Weight Loss / Q000502:physiology*