Effects of Gastric Bypass Surgery on Bone Mass and Microarchitecture Occur Early and Particularly Impact Postmenopausal Women

Abstract

Roux-en-Y gastric bypass (RYGB) surgery is a highly effective treatment for obesity but negatively affects the skeleton. Studies of skeletal effects have generally examined areal bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA), but DXA may be inaccurate in the setting of marked weight loss. Further, as a result of modestly sized samples of mostly premenopausal women and very few men, effects of RYGB by sex and menopausal status are unknown. We prospectively studied the effects of RYGB on skeletal health, including axial and appendicular volumetric BMD and appendicular bone microarchitecture and estimated strength. Obese adults (N = 48; 27 premenopausal and 11 postmenopausal women, 10 men) with mean ± SD body mass index (BMI) 44 ± 7 kg/m were assessed before and 6 and 12 months after RYGB. Participants underwent spine and hip DXA, spine QCT, radius and tibia HR-pQCT, and laboratory evaluation. Mean 12-month weight loss was 37 kg (30% of preoperative weight). Overall median 12-month increase in serum collagen type I C-telopeptide (CTx) was 278% (p < 0.0001), with greater increases in postmenopausal than premenopausal women (p = 0.049). Femoral neck BMD by DXA decreased by mean 5.0% and 8.0% over 6 and 12 months (p < 0.0001). Spinal BMD by QCT decreased by mean 6.6% and 8.1% (p < 0.0001); declines were larger among postmenopausal than premenopausal women (11.6% versus 6.0% at 12 months, p = 0.02). Radial and tibial BMD and estimated strength by HR-pQCT declined. At the tibia, detrimental changes in trabecular microarchitecture were apparent at 6 and 12 months. Cortical porosity increased at the radius and tibia, with more dramatic 12-month increases among postmenopausal than premenopausal women or men at the tibia (51.4% versus 18.3% versus 3.0%, p < 0.01 between groups). In conclusion, detrimental effects of RYGB on axial and appendicular bone mass and microarchitecture are detectable as early as 6 months postoperatively. Postmenopausal women are at highest risk for skeletal consequences and may warrant targeted screening or interventions. © 2017 American Society for Bone and Mineral Research.

G-CSF partially mediates effects of sleeve gastrectomy on the bone marrow niche

“…The mechanisms by which bariatric surgery improve glucose homeostasis, independent of weight loss, appear to be complex and involve energy expenditure, macronutrient preference, luminal composition of the gut (i.e., microbiota and bile acids), adaptation of the gastrointestinal lining, altered postprandial gut hormone secretions, increases in insulin-dependent and -independent glucose disposal, pancreas morphology, and absorption of micronutrient and minerals (6). Bariatric surgeries are associated with other on-and off-target side effects, including macro-and micronutrient malabsorption, hypoglycemia, anemia, rapid bone loss, and a higher fracture risk (7)(8)(9)(10). Potential causes of bone loss independent of weight loss with VSG in humans and animal models have been explored, and include adaptation to unloading, abnormalities in calciotropic hormones, and altered gut and adipokine hormones (8,(11)(12)(13)(14)(15).…”

Management of fracture risk in patients with diabetes—Chinese Expert Consensus

“…Another retrospective nested case‐control study in more than 12 000 patients undergoing bariatric surgery with a follow‐up period of 4.4 years and other small‐sample studies show a two‐ to 3 fold increase in the fracture risk after bariatric surgery, which is observed primarily in patients undergoing biliopancreatic diversion surgery . Postmenopausal women undergoing Roux‐en‐Y gastric bypass may experience trabecular microstructural damage and decreased BMD during the first 6 months after the operation . Decreased BMDs have also been reported in Chinese obese individuals after bariatric procedures, especially in females .…”

“…104 Postmenopausal women undergoing Roux-en-Y gastric bypass may experience trabecular microstructural damage and decreased BMD during the first 6 months after the operation. 105 Decreased BMDs have also been reported in Chinese obese individuals after bariatric procedures, especially in females. 106 Therefore, patients scheduled for bariatric surgery should receive a comprehensive evaluation of the fracture risk before surgery and receive interventions as needed after surgery.…”

“…Decreased BMDs have also been reported in Chinese obese individuals after bariatric procedures, especially in females . Therefore, patients scheduled for bariatric surgery should receive a comprehensive evaluation of the fracture risk before surgery and receive interventions as needed after surgery …”

“…106 Therefore, patients scheduled for bariatric surgery should receive a comprehensive evaluation of the fracture risk before surgery and receive interventions as needed after surgery. [105][106][107]…”