Effect of weight loss after Roux-en-Y gastric bypass, on renal function and blood pressure in morbidly obese patients.
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.
Serpa Neto
Ary
A
Division of Clinical and Surgical Treatment of Obesity, ABC Medicine School, São Paulo, Brazil. aryserpa@terra.com.br
Bianco Rossi
Felipe Martin
FM
Dal Moro Amarante
Rodrigo
R
Alves Buriti
Nara
N
Cunha Barbosa Saheb
Gabriel
G
Rossi
Marçal
M
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*