Weight Loss Due to Bariatric Surgery Harms Bone Density: Presented at ADA


Weight loss as a result of bariatric surgery may be detrimental to bone health, according to research presented here at the 66th Scientific Sessions of the American Diabetes Association (ADA).


Robert Considine, PhD, PhD, assistant professor, endocrinology division, Indiana University School of Medicine, Indianapolis, Indiana, and associates examined the effect of weight loss on serum markers of bone turnover in 10 premenopausal women and 10 middle-aged men before and 6 months after laparoscopic Roux-en-Y gastric bypass surgery.


Population-adjusted rates of bariatric surgery increased more than 7-fold in the U.S. population, from 3.5 per 100,000 in 1996 to 24.0 per 100,000 in 2002.


It is imperative that the long-term effects of the significant weight loss associated with bariatric surgery be investigated, Dr. Considine said in his presentation on June 11th.
Results of the study showed that while bariatric surgery-induced weight loss may have a significant positive effect on lipid and glucose metabolism, these patients have significant reductions in body mass index.

At baseline and at 6 months after surgery, the researchers measured levels of serum osteocalcin, bone-specific alkaline phosphatase (BAP), and N-telopeptide cross-linked collagen type 1 (NTX), which are indicative of bone resorption.
At 6 months, there was a decrease in mean body mass index (BMI) of 31.0% ± 2.3% in men and 32.4% ± 1.6% in women.

Follow up:

The investigators also documented a significant increase for the entire group in levels of serum osteocalcin. The increase in these biomarkers was similar for men and women.


Circulating levels of calcium and phosphate were unchanged at 6 months after surgery.


Weight loss was associated with a significant reduction in serum levels of glucose.


The researchers recommend that future studies include repeat measurements of serum bone marker turnovers after 1 year or more of weight loss. Elucidation of a possible cause-and-effect relationship between serum leptin and NTX will result in a better understanding of bone health following bariatric surgery-induced weight loss, according to the researchers.


Source: Jill Stein for Doctor's Guide