Expired CME Article

Metabolic, Renal, and Nutritional Consequences of Bariatric Surgery: Implications for the Clinician

Authors: Veeraish Chauhan, MD, Megha Vaid, MPH, Mohit Gupta, MD, Atul Kalanuria, MD, Akhil Parashar, MBBS


Management of obesity-associated comorbidities costs about $60 billion/year, about 5% of total US healthcare expenditure. Bariatric surgery is the only proven effective weight loss therapy for severely obese patients with a BMI ≥35 kg/m2. Bariatric surgery produces long-term weight loss, improves quality of life, and reduces the number of sick days and medication costs. Surgery has a profound effect on the metabolic milieu and nutritional status from the first few days after surgery, even before significant weight loss has been achieved. Metabolic effects of bariatric surgery reduce obesity-related comorbidities like type 2 diabetes, hypertension, metabolic syndrome, and cardiovascular disease risk. Improvement in renal function is seen, but adverse effects like oxalate nephropathy can lead to chronic kidney disease or end-stage renal disease (CKD/ESRD). Surgery can also lead to micronutrient deficiencies, making dietary supplementation necessary. Reduction in insulin resistance and hypertension after surgery makes medication adjustment imperative. Improvement in comorbidities and nutritional deficiencies after bariatric surgery has important clinical implications.

Key Points

* Reduction in obesity-related mortality and comorbidities after bariatric surgery is largely due to metabolic effects like decreased insulin resistance, better blood pressure control, and improvements seen in the lipid profile.

* Improved renal function is usually seen after surgery; however, oxalate nephropathy is a potential complication that can lead to irreversible renal failure.

* Increased insulin sensitivity, decreased baseline blood pressure and low-density lipoprotein levels, and improvement in kidney function make medication adjustments imperative after bariatric procedures. Nutritional requirements change and need to be monitored, and supplementation may be required.

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