Patients May Have Increased Fracture Risk after Bariatric Surgery
For all of the detrimental effects that excess body weight has on a person’s health, there is one slight advantage to being a little heavier. Studies have linked a greater body weight with greater bone mass, including total bone mineral content and total bone mineral density. Patients who have had bariatric surgery, and have lost a significant amount of weight, appear to be at a greater risk for bone fractures than was once previous thought.
Gastric Bypass Patients Have Greater than 2 Times Increased Risk for Fractures
Researchers with the Mayo Clinic College of Medicine followed a total of 258 patients who belonged to a small subset of a larger study. The patients underwent bariatric surgery at the Clinic between 1985 and 2004, with 94% having a gastric bypass. The patients were compared to healthy controls matched for age and sex living in the same county in Minnesota.
The full analysis showed that patients who have had bariatric surgery have a 2.3 time increased risk of fractures at all skeletal sites studied, but especially the hands and feet. On average, the patients experienced their first fracture about six years after surgery.
“A negative effect on bone health that may increase the risk of fractures is an important consideration for people considering bariatric surgery and those who have undergone bariatric surgery,” said Kelly Nakamura, a medical student and lead author of the study.
Dr. Kurt Kennel MD, an assistant professor of medicine in the endocrinology division, notes that patients who were more physically active before surgery had a lower fracture risk than those who were less active. Exercise is known to increase bone density and improve bone health. The best exercise for building and maintaining bone are weight resistance exercises, such as weight lifting, two or three times a week.
Calcium intake is also an important consideration after gastric bypass surgery. Patients are often recommended to take the Calcium Citrate form of the mineral as it is best absorbed in the low acid environment of the post-bypass pouch. Calcium supplements should be limited to 500 milligrams at once to maximize absorption and should contain vitamin D, which helps the body to absorb the mineral.
Dr. Kennel says that the study does not conclude that gastric bypass patients will eventually go on to develop osteoporosis and there is no data on whether osteoporosis medications such as bisphosphonates are safe or appropriate for this patient population. “Further research is needed to understand why bariatric surgery negatively affects bone health and how to best prevent these fractures,” he said.
The study findings were presented at the recent Endocrine Society’s 93rd Annual Meeting held in Boston.