Insulin-like growth factor binding protein 2 null mice (Igfbp2-/-) are protected against trabecular bone loss after vertical sleeve gastrectomy

Authors

Benjamin T. Harris, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, ME, 04074, USA. bharris12@une.edu.
Phuong T. Le, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, ME, 04074, USA.
Janaina Da Silva Martins, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, ME, 04074, USA.
Lama Alabdulaaly, Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, 02115, USA.
Roland Baron, Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, MA, 02115, USA.
Mary L. Bouxsein, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02115, USA.
Clifford J. Rosen, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, ME, 04074, USA.Follow
Alison N. Pletch, Maine Medical Center Research Institute, Maine Medical Center, Scarborough, ME, 04074, USA.

Document Type

Article

Publication Date

2-28-2022

Journal Title

Surgical endoscopy

Abstract

BACKGROUND: Bariatric surgery has been shown to result in weight loss, improved hemoglobin A1C, and decreased mortality but can also lead to bone loss and increased fracture rates. Serum IGFBP-2 is elevated in patients after bariatric surgery and although it may lead to improved blood glucose, may also drive bone resorption, and inhibit IGF-I action. This study tested the hypothesis that Igfbp2-/- mice were acutely protected from bone loss after vertical sleeve gastrectomy (VSG). METHODS: Thirty-four mice, 17 Igfbp2-/- and 17 + / + underwent a hand-sewn VSG or sham surgery, at 16 weeks of age. Mice were harvested at 20 weeks of age. DXA was measured for body composition, areal bone mineral density (aBMD), areal bone mineral content (aBMC), femoral bone mineral density (fBMD), and femoral bone mineral content (fBMC) at 15, 18, and 20 weeks of age. Micro-computed tomography and serum ELISA assays were measured and analyzed at 20 weeks of age. RESULTS: Both Igfbp2-/- and + / + mice lost significant weight (P = 0.0251, P = 0.0003, respectively) and total fat mass (P = 0.0082, P = 0.0004, respectively) at 4 weeks after VSG. Igfbp2+/+ mice lost significant aBMD, fBMD, fBMC, trabecular BMD, trabecular BV/TV and cortical tissue mineral density (P = 0.0150, P = 0.0313, P = 0.0190, P = 0.0072, and 0.0320 respectively). The Igfbp2-/- mice did not show significant bone loss in these parameters nor in trabecular BV/TV. Both Igfbp2-/- and + / + mice had less cortical bone area (P = 0.0181, P =  < .00001), cortical area over total area (P = 0.0085, P = 0.0007), and cortical thickness (P = 0.0050, P =  < 0.0001), respectively. Igfbp2+/+ mice demonstrated significantly lower polar, minimum, and maximum moments of inertia (P = 0.0031, P = 0.0239, and P = 0.0037, respectively). Igfbp2+/+ had significantly higher levels of IGFBP-2 at 2 weeks postoperatively after VSG (P = 0.035), and elevated levels of CTx and P1NP (P = 0.0127, P = 0.0058, respectively). CONCLUSIONS: Igfbp2-/- mice were protected against trabecular bone loss and had attenuated cortical bone loss 4 weeks after VSG.

Recommended Citation

Harris BT, Le PT, Da Silva Martins J, et al. Insulin-like growth factor binding protein 2 null mice (Igfbp2-/-) are protected against trabecular bone loss after vertical sleeve gastrectomy [published online ahead of print, 2022 Feb 28]. Surg Endosc. 2022;10.1007/s00464-022-09069-1. doi:10.1007/s00464-022-09069-1