Urine composition changes in patients after gastric bypass surgery, which increase the risk of kidney stones, according to an American study reported in the Journal of Urology
Researchers from the University of Texas Southwestern Medical Center tested urine samples from 38 obese patients, which they divided into two groups – 16 women and 3 men each. Some of them underwent surgical gastric bypass surgery, while the other did not.
The operation to create a gastric bypass consists in dividing this organ into two parts and connecting a branch of the intestine to the smaller part. Thus, the stomach is reduced in size and part of the small intestine is excluded from food absorption.
It turned out that patients after gastric reduction surgery more often had large amounts of oxalate in their urine, which contribute to the formation of kidney stones, than non-operated patients – in the group after surgery, it was 47%. people, and the control group – 10,5 percent.
In addition, people after gastric bypass were more likely than controls to have low levels of citrate in their urine, which inhibit stone formation.
According to the main author of the work, Dr. Naim Maalouf, these results indicate that after gastric bypass surgery, almost half of patients who previously had no nephrolithiasis are at risk of developing this disease. This complication may not be associated with surgery as it usually appears months or years after surgery.
The reason for the increased risk of kidney stones after surgical gastric reduction is not entirely clear, but the results of these studies show that patients who have undergone such surgery and the doctors who care for them should be particularly alert to this risk, emphasizes Dr. Maalouf. (PAP)