HealthDay News — Glucose metabolism and weight are associated with marrow fat behavior, and marrow fat may determine bone mass after Roux-en-Y gastric bypass (RYGB), according to a study published online in the Journal of Bone and Mineral Research.
Tiffany Y. Kim, MD, from the University of California in San Francisco, and colleagues enrolled 30 women, stratified by diabetes status. The authors measured bone mineral density (BMD) and vertebral marrow fat content before and 6 months after RYGB.
The researchers found that patients with higher marrow fat at baseline had lower BMD. Total body fat decreased considerably in all participants postoperatively. There was variation in the effects of RYGB on marrow fat by diabetes status. No significant mean change was seen in marrow fat for women without diabetes; marrow fat increases were more likely among those who lost more total body fat.
Women with diabetes had a mean marrow fat change of −6.5%. Decreases in marrow fat were seen for those with greater improvements in hemoglobin A1c. There was a correlation for insulin-like growth factor 1 with marrow fat declines. A negative association was seen for marrow fat and BMD changes; independent of age and menopause, patients with marrow fat increases had more BMD loss at both spine and femoral neck.
“Our findings suggest that glucose metabolism and weight loss may influence marrow fat behavior, and marrow fat may be a determinant of bone metabolism,” the authors write.
Kim TY, Schwartz AV, Li X, et al. Bone marrow fat changes after gastric bypass surgery are associated with loss of bone mass [published online August 9, 2017]. J Bone Miner Res. doi:10.1002/jbmr.3212