Review of bariatric surgery and effects on proteinuria. (#214)
Introduction: Obesity is a risk factor for development of chronic renal disease.1,2 The proposed mechanism of obesity related impaired renal function is thought to be multifactorial and could be mediated by adipogenic tissue inflammation or endothelial dysfunction and hyperfiltration leading to proteinuria, irreversible renal damage and glomerulomegaly.3 Bariatric surgery has proven to show long term reversal of obesity, diabetes and metabolic derangements.4 The effect on renal function is still unclear. We aimed to review the literatures on bariatric surgery and its effect on albumin excretion.
Method: Papers were selected following online searches in Embase, Ovid and Pubmed databases. Relevant interventional studies related to albuminuria were chosen. There were 66 articles on bariatric surgery + albuminuria. 7 studies with surgical interventions and outcomes of albumin/proteinuria were chosen.
Results: All studies unanimously demonstrated significant improvements in micro-albuminuria/proteinuria in patients with or without macro-albuminuria. Majority of studies were single arm, retrospectively analysed with varied follow up periods from 1 month to 2 years and were mainly Roux-en-Y gastric bypass surgery.
Conclusion: Reduction in albuminuria post-operatively has been demonstrated. There are other frequently used bariatric surgical methods, such as gastric banding and sleeve gastrectomy. More studies are required to compare the different techniques and their effects on renal parameters but also to evaluate the mechanism in which renal function improves post-operatively. Assessing the time taken to exhibit reduction in albuminuria, in comparison with rate of weight loss may help define whether weight loss or other metabolic/hormonal factors are at play.
- 1. Hsu C-y, McCulloch CE, Iribarren C, et al. Body mass index and risk for end-stage renal disease. Ann Intern Med. 2006;144:21–8.
- 2. Ejerblad E, Fored CM, Lindblad P, et al. Obesity and risk for chronic renal failure. J Am Soc Nephrol. 2006;17:1695–702.
- 3. Wahba I, Mak R. Obesity and obesity-initiated metabolic syndrome: mechanistic links to chronic kideny disease. Clin J Am Soc Nephrol. 2007;2:550–62.
- 4. Buchwald H, Avidor Y, Braunwald E, et al. Bariatric surgery: a systematic review and meta-analysis. JAMA. 2004;292:1724–37.