Bone Mineral Density and Turnover After Sleeve Gastrectomy and Gastric Bypass: A Randomized Controlled Trial (Oseberg)

Abstract

Context Bariatric surgery, particularly Roux-en-Y gastric bypass (RYGB), is associated with increased risk of osteoporotic fractures. It is unknown whether RYGB or sleeve gastrectomy (SG) have different effects on bone health. Objective To compare changes in bone mineral density and markers of bone turnover one year after SG and RYGB. Design, Setting, Patients, and Interventions Randomized, triple-blind, single-center trial at a tertiary care center in Norway. Primary outcome was diabetes remission. Patients with severe obesity and type 2 diabetes were randomized and allocated (1:1) to SG or RYGB. Main Outcome Measures Changes in areal bone mineral density (aBMD) and bone turnover markers. Results Femoral neck, total hip, and lumbar spine aBMD, but not total body aBMD, decreased significantly more after RYGB (n=44) than after SG (n=48) [mean (95% CI) between group differences -2.8 % (-0.8 to -4.7), -3.0 % (-0.9 to -5.0), -4.2 % (-2.1 to -6.4), and -0.5 % (0.6 to -1.6), respectively]. The increase in procollagen type 1 N-terminal propeptide (P1NP) and C-telopeptide of type I collagen (CTX-1) were approximately 100% higher after RYGB than after SG, (both time x group, P<0.001). The changes in femoral neck, total hip and lumbar spine aBMDs and the changes in P1NP and CTX-1 were independently associated with the surgical procedure (all P<0.05) and not weight change. Conclusions RYGB was associated with greater reduction in aBMD and greater increase in bone turnover markers compared with SG. This finding could suggest greater skeletal fragility after RYGB.

Bone Response to Weight Loss Following Bariatric Surgery

“…At the hip, BMD loss was significantly higher in patients undergoing SG (-9.2%) and RYGB (-9.5%) than intensive medical therapy group (-0.3%), whereas at lumbar spine a significant decrease in BMD was only observed in the SG group (-2.3%), without changes in RYGB (0.4%) and intensive medical therapy groups (0.8%). A subsequent randomized controlled trial in patients with obesity and T2DM demonstrated that subjects undergoing RYGB had a higher decrease in BMD at the femoral neck (mean between-group difference -2.8%, 95% CI -4.7 to -0.8), total hip (mean betweengroup difference -3.0%, 95% CI -5.0 to -0.9) and lumbar spine (mean between-group difference -4.2%, 95% CI -6.4 to -2.1) than patients undergoing SG (45).…”

“…Comparative analyses between RYBP and SG showed a significantly higher increase in CTX, P1NP, TRAcP5b with the former, and a greater increase in total OC and uOC with the latter, suggesting a predominating bone resorption over bone formation markers during RYGB ( 36 ). A randomized triple-blind trial showed an approximately 100% higher increase in P1NP and CTX-1 levels after RYGB than SG at 1-year post surgery ( 45 ). Likewise, studies after biliopancreatic diversion (BPD) showed that CTX increased significantly at 3 days (+ 66%), 3 months (+ 219%), and 12 months (+ 295%), while OC decreased at 3 days (- 19%) then increased at 3 months (+ 69%) and 12 months (+ 164%), suggesting an earlier and greater increase in bone resorption over bone formation markers with BPD ( 120 ).…”

“…While the skeletal response to the effects of bariatric surgery has been collectively confirmed in systematic reviews and meta-analyses, discrepancies still exist in terms of affected bone regions and timing of dynamic bone changes ( 30 , 42 , 43 ). As such, dual-energy X-ray absorptiometry (DXA) studies have shown significant BMD loss at the hip with less consistent results for the lumbar spine ( 44 , 45 ). Despite weight stabilization and maintenance of metabolic parameters, bone loss and deterioration in bone strength continued years following bariatric surgery, supporting the hypothesis that fracture risk does not appear to be dependent on weight loss, and rather it increases with observation time ( 46 ).…”

Protocol for a pilot randomised controlled trial of zoledronic acid to prevent bone loss following sleeve gastrectomy surgery

“…Finally, the use of zoledronic acid is a strength because a single dose has been shown to suppress bone turnover in various disease states (osteoporosis, 30 Paget’s disease, 31 HIV 32 and androgen deprivation therapy 33 ) for between 12 months and 6.5 years. 11 Considering SG results in increased bone turnover for anywhere between 1 and 5 years following surgery, 34 35 zoledronic acid, with its robust bone turnover suppression, is an ideal treatment option in this population to combat skeletal fragility.…”

Effects of physical training on physical and functional fitness, physical activity level, endothelial function, hemodynamic variables, bone metabolism, and quality of life of post-bariatric patients: study protocol for a randomized controlled trial

“…Unfortunately, there is accumulated evidence demonstrating a reduction in bone mineral density (BMD) [9,10] after a bariatric procedure. Studies that compared the two most commonly performed techniques [11] showed significantly more bone loss after Rouxen-Y gastric bypass (RYGB) than after sleeve gastrectomy (SG), especially in the lumbar spine, total hip, and femoral neck [9,10]. This undesired event may result in greater skeletal frailty and risk of fractures [12,13].…”