Metabolic syndrome and bariatric surgery in stone disease etiology

To review the prevalence and mechanisms of stone formation in patients with metabolic syndrome and in those submitted to bariatric surgery.

MetS is associated with urinary stone disease, which appears to be sustained by dietetic factors and insulin resistance. The latter represented in obesity and diabetes favors uric acid precipitation in urine via a more acidic urinary load. Patients submitted to modern bariatric surgery are at risk of nephrolithiasis and nephropathy as a consequence of malabsorption and hyperoxaluria, which are more consistent after Roux-en-Y gastric bypass than after gastric banding. Other stone risk factors such as hypocitraturia may also be present.

Patients with metabolic syndrome and those submitted to modern bariatric surgery are both at risk of nephrolithiasis and nephropathy. Accurate stone screening careful monitoring of renal function and diet counseling are strongly encouraged in these patients.