The effect of biliopancreatic diversion surgery on renal function--a retrospective study.

BACKGROUND

The prevalences of obesity and chronic kidney disease (CKD) have increased simultaneously. Should a pathophysiological relationship exist between the two conditions, bariatric surgery and associated weight loss could be an important intervention in extremely obese individuals to slow the progression of CKD.

METHODS

We conducted a retrospective analysis of 25 patients who had undergone biliopancreatic diversion (BPD) surgery for extreme obesity (body mass index >40 kg/m(2)), with mean follow-up of 4 years. We assessed pre- and post-surgery renal function, body weight and blood pressure (BP) obtained from electronic hospital and primary care records.

RESULTS

There was a significant reduction in mean body weight at 4 years by 50.3 kg (SD = 20.65). The creatinine and estimated glomerular filtration rate (eGFR) also improved significantly: serum creatinine reduced by 16.2 μmol/l (SD = 19.57) while the eGFR improved by 10.6 ml/min/m(2) (SD = 15.45). The greatest improvement in eGFR was in the group (n = 7) with eGFR ≤60 ml/min/m(2). A subset of patients (n = 11) had evaluable BP readings and had a reduction in BP of 17/10 mmHg (SD = 33/12).

CONCLUSIONS

This retrospective study demonstrates a clinically significant improvement in renal function following BPD. Several mechanisms including weight loss could account for the positive impact on renal function. The physiology underlying this improvement requires further study.