Obesity and chronic kidney disease

Abstract

Background/aims: The prevalence of obesity among U.S. adults has doubled within the past two decades, and if trends continue, over one-third of U.S. adults may be obese by the year 2008. Concurrent with the rising prevalence of obesity is an epidemic of chronic kidney disease (CKD) with an estimated 18 million U.S. adults currently affected. This review discusses the strong and consistent association between CKD risk and increasing body mass index noted in several observational studies. Potential mechanisms for obesity's role in the development and progression of CKD and secondary focal segmental glomerulosclerosis are also discussed.

Methods: Literature review.

Results: Although obesity is an important risk factor for diabetes and hypertension, the two most common etiologies of kidney failure, obesity itself may increase CKD risk by increasing the metabolic demands on the kidney, which leads to higher glomerular capillary pressures and glomerular hypertrophy. The hyperinsulinemia frequently linked with obesity may also accelerate structural damage by interacting with angiotensin II and increasing collagen production and deposition. The histologic changes in the kidney noted in some obese, especially morbidly obese, adults frequently mimic those changes associated with secondary focal segmental glomerulosclerosis, which may occur in disease states such as severely reduced nephron mass and hemodynamic stress. Given the presence of genetic susceptibility and/or reduced nephron mass, obesity may potentiate the development and progression of secondary focal segmental glomerulosclerosis.

Conclusions: Obesity is an important risk factor for CKD. Treatment plans for obese adults with CKD should include weight loss and exercise because these interventions may simultaneously reduce the metabolic demands on the kidney, lower systemic and glomerular pressures, and improve insulin sensitivity. However, more studies are needed to further optimize the treatment and prevention of CKD associated with obesity.