Long-term Complications of Bariatric Surgery

To the Editor The review of benefits and risks of bariatric surgery by Dr Arterburn and colleagues emphasized the efficacy and safety of the procedure, as well as many of the long-term benefits. However, there are 2 additional risks often overlooked by practitioners: recurrent calcium oxalate urolithiasis and osteoporosis. Both risks appear to be more frequent after Roux-en-Y gastric bypass (RYGB), in which the principal site of calcium absorption, the duodenum, is bypassed. A marked increase in oxalate excretion after RYGB can be difficult to treat. Urinary calcium, on the other hand, is low, consistent with calcium malabsorption. The osteoporosis that develops after RYGB is unrelated to weight loss or to alterations in vitamin D metabolism. Yet neither complication is remedied easily by supplementation with oral calcium. Therefore, more research is needed to delineate the pathophysiologic mechanisms. Patients considering bariatric surgery should be counseled about the risk of developing these complications. After surgery, measurements of 24-hour urinary calcium and oxalate and regular bone densitometry are indicated.
Source: JAMA - Category: General Medicine Source Type: research