NEW YORK, 12 june 2009– The dramatic and sustained increase in bone turnover that occurs following surgery for obesity, or "bariatric surgery," translates into a significantly increased risk of fractures, especially in the hands and feet, according to a study presented today at The Endocrine Society's annual meeting in Washington, DC.
The study team, from the Mayo Clinic, Rochester, Minnesota, compared the fracture rate in 97 patients (average age of 44 years) who underwent bariatric surgery to the rate expected in individuals of the same age and sex in the general population.
Gastric bypass was performed in 90 percent of the subjects while 10 percent had either vertical banded gastroplasty or biliopancreatic diversion. Eighty-six of the subjects were women.
Within an average of 7 years after surgery, 21 bariatric surgery patients experienced a total of 31 fractures, the investigators report.
"We showed that patients who have had bariatric surgery have about a twofold increased risk in developing a fracture or sustaining a fracture as compared to the normal population," said study presenter Dr. Elizabeth Chittilapilly Haglind.
The surgical patients' risk of a first fracture at any site was increased by 80 percent. The increased risk was 40 percent for a first fracture at the hip, wrist, spine or arm; the risk of fracture at all other sites was doubled. The risk of hand or foot fracture was the most elevated, with an increase of more than threefold and almost fourfold, respectively.
In a statement from the meeting, study co-investigator Dr. Jackie Clowes said: "It is currently unclear why fractures are more common after bariatric surgery, especially at the hand and foot. Although aggressive calcium and vitamin D supplementation after (bariatric) surgery may well help, it may still be insufficient to prevent the increased risk of fracture."
Haglind added, "More research is needed to confirm our findings and understand the specific risk factors and mechanisms involved."