Jung Grace H, Zahedi Bita, Bouxsein Mary L, Yu Elaine W
Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, United States.
Harvard Medical School, Boston, MA 02115, United States.
JBMR Plus. 2024 Dec 30;9(3):ziae175. doi: 10.1093/jbmrpl/ziae175. eCollection 2025 Mar.
Bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) and adjustable gastric banding (AGB) lead to long-term deficits in bone density but are also accompanied by decreased weight, which may lower the impact force with falls. The aim of this study was to compare the long-term skeletal impact of RYGB and AGB using a biomechanical evaluation of load-to-strength ratio at the distal radius as a surrogate for wrist fracture risk. We conducted a cross-sectional study evaluating bone microarchitectural parameters and bone turnover in adults who received either RYGB or AGB surgery ≥10 yr ago (RYGB: = 22; AGB: = 23). Bone strength at the distal radius was estimated by microfinite element analysis from HR-pQCT. We used a single-spring biomechanical model to estimate impact force and then calculated load-to-strength ratio as a ratio of impact force to bone strength, with higher load-to-strength ratios representing a higher susceptibility to fracture. In multivariable analyses, the RYGB group had higher bone resorption marker C-telopeptide (CTX) levels, lower volumetric bone density, and worse cortical and trabecular microarchitectural parameters than the AGB group. Furthermore, estimated bone strength at the radius was lower in the RYGB group (3725 ± 139 N vs 4141 ± 157 N, = .030), and the load-to-strength ratio was higher in RYGB group as compared with AGB (0.84 ± 0.04 vs 0.72 ± 0.05, = .035), suggestive of higher propensity for wrist fracture. Taken together, these results indicate the long-term deleterious skeletal effects are more concerning with RYGB than AGB.
诸如Roux-en-Y胃旁路术（RYGB）和可调节胃束带术（AGB）等减肥手术会导致骨密度长期下降，但同时体重也会减轻，这可能会降低跌倒时的冲击力。本研究的目的是通过对桡骨远端负荷与强度比进行生物力学评估，作为腕部骨折风险的替代指标，比较RYGB和AGB对骨骼的长期影响。我们进行了一项横断面研究，评估≥10年前接受RYGB或AGB手术的成年人的骨微结构参数和骨转换情况（RYGB组：n = 22；AGB组：n = 23）。通过高分辨率外周定量CT的微有限元分析来估计桡骨远端的骨强度。我们使用单弹簧生物力学模型来估计冲击力，然后计算负荷与强度比，即冲击力与骨强度之比，负荷与强度比越高表示骨折易感性越高。在多变量分析中，RYGB组的骨吸收标志物C-末端肽（CTX）水平较高，骨体积密度较低，皮质和小梁微结构参数比AGB组更差。此外，RYGB组桡骨的估计骨强度较低（3725 ± 139 N vs 4141 ± 157 N，P = .030），与AGB组相比，RYGB组的负荷与强度比更高（0.84 ± 0.04 vs 0.72 ± 0.05，P = .035），提示腕部骨折倾向更高。综上所述，这些结果表明RYGB比AGB对骨骼的长期有害影响更令人担忧。
