Supersized kidneys: Lessons from the preclinical obese kidney.

The worldwide prevalence of obesity continues to rise. Obesity has been shown to increase the risk of both the development and the progression of renal failure, even after correction for other comorbid conditions. The ability of nephrologists to intervene will require greater understanding of obesity's renal physiologic effects. Kidney biopsies and functional studies performed on morbidly obese patients without overt renal disease who presented for bariatric surgery have helped to elucidate the earliest obesity-related structural and functional responses.