Researchers at John Hopkins have released statistics showing that patients who have undergone the gastric bypass surgery known as Roux-en-Y have an increased risk for forming kidney stones post surgery.
While in the past surgeons have known about the increased incidence of kidney stones in post weight loss surgery patients, surgeons did not associate this with the Roux-en Y procedure.
Currently, the Roux-en Y procedure is the most performed of the weight loss surgeries in the United States.
Between 2002 and 2006, researchers tracked 4,639 patients who had the Roux-en Y operation. For a comparison, they also tracked another 4,639 patients who were overweight but who had not had weight loss surgery and were comparable in age, weight, BMI, and gender.
The study revealed that 8% of patients post Roux-en Y surgery developed kidney stones. These findings were about twice the incidence of the control group.
The study was led by Dr Brian Matlaga, MD, an Assistant Professor of Urology at the John Hopkins University School of Medicine. He is also a Director of Stone Diseases at Hopkins’ James Buchanan Brady Urological Institute.
Bariatric weight loss operations reduce the amount of calcium that can be absorbed into the system. This is due to the stomach size being decreased, and parts of the small bowel being bypassed in the process of digestion of food.
Normally, calcium binds with a substance known as oxalate which is then flushed out of the body. (An excess of oxalate is one of the causes of kidney stones.) So patients who have had weight loss surgery often do not have the necessary amounts of calcium required to rid the body of the oxalate. Hence the formation of kidney stones.
Weight loss surgery patients can reduce their risk for producing kidney stones by taking calcium supplements and any other products recommended by their surgeon.
Over 200,000 people in the US will undergo weight loss surgery annually. The health benefits obtained from weight loss surgery for the seriously overweight far outweigh the production of kidney stones. Weight loss surgery patients can reduce the likelihood of developing kidney stones by the addition of calcium supplements in their post surgery diet. Consult your surgeon for more information.