Pamela S Hinton1, Kartik Shankar2, Lynn M Eaton3, R Scott Rector4. 1. Department of Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA. Electronic address: hintonp@missouri.edu. 2. Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA, Arkansas Children's Nutrition Center, Little Rock, AR, USA. 3. Department of Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA. 4. Research Service-Harry S Truman Memorial Veterans Medical Center, and Departments of Medicine-Division of Gastroenterology and Hepatology and Nutrition and Exercise Physiology, University of Missouri-Columbia, Columbia, MO, USA.
Abstract
PURPOSE: To examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. METHODS: This was a 36-week study of sedentary, hyperphagic, male OLETF rats (OLETF-SED), exercise-treated OLETF rats (OLETF-EX) and sedentary non-hyperphagic controls (LETO-SED) with data collection at 13, 20, and 40 weeks of age (n = 5-8 animals per group per timepoint). RESULTS: Body mass and fat (%) were significantly greater in OLETF-SED versus controls. OLETF-SED were insulin resistant at 13 and 20 weeks, with overt diabetes by 40 weeks. At 13weeks, OLETF-SED had lower total body BMC and BMD and serum P1NP compared with LETO-SED. Differences in total body BMC and BMD between OLETF-SED and LETO-SED persisted at 20 weeks, with reductions in total and cortical BMD of the tibia. OLETF-SED also had lesser femur diameter, cross-sectional area, polar moment of area, and torque at fracture than LETO-SED. By 40 weeks, OLETF-SED had elevated bone resorption and reduced intrinsic bone strength. OLETF-EX did not show the excessive weight gain, obesity, insulin resistance or diabetes observed in OLETF-SED. OLETF-EX had greater BMD than OLETF-SED, and structural and material properties of the femur were significantly increased in OLETF-EX relative to OLETF-SED and LETO-SED. CONCLUSIONS: The negative skeletal effects of excessive adiposity and insulin resistance were evident early in the progressive obesity with lasting negative impacts on intrinsic and extrinsic bone strength. Exercise protected against obesity-associated skeletal changes with marked benefits on the biomechanical properties of bone.
PURPOSE: To examine how the development of obesity and the associated insulin resistance affect bone structural and material properties, and bone formation and resorption markers in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat model. METHODS: This was a 36-week study of sedentary, hyperphagic, male OLETFrats (OLETF-SED), exercise-treated OLETFrats (OLETF-EX) and sedentary non-hyperphagic controls (LETO-SED) with data collection at 13, 20, and 40 weeks of age (n = 5-8 animals per group per timepoint). RESULTS: Body mass and fat (%) were significantly greater in OLETF-SED versus controls. OLETF-SED were insulin resistant at 13 and 20 weeks, with overt diabetes by 40 weeks. At 13weeks, OLETF-SED had lower total body BMC and BMD and serum P1NP compared with LETO-SED. Differences in total body BMC and BMD between OLETF-SED and LETO-SED persisted at 20 weeks, with reductions in total and cortical BMD of the tibia. OLETF-SED also had lesser femur diameter, cross-sectional area, polar moment of area, and torque at fracture than LETO-SED. By 40 weeks, OLETF-SED had elevated bone resorption and reduced intrinsic bone strength. OLETF-EX did not show the excessive weight gain, obesity, insulin resistance or diabetes observed in OLETF-SED. OLETF-EX had greater BMD than OLETF-SED, and structural and material properties of the femur were significantly increased in OLETF-EX relative to OLETF-SED and LETO-SED. CONCLUSIONS: The negative skeletal effects of excessive adiposity and insulin resistance were evident early in the progressive obesity with lasting negative impacts on intrinsic and extrinsic bone strength. Exercise protected against obesity-associated skeletal changes with marked benefits on the biomechanical properties of bone.
Authors: Danielle M Frechette; Divya Krishnamoorthy; Tee Pamon; M Ete Chan; Vihitaben Patel; Clinton T Rubin Journal: Ann N Y Acad Sci Date: 2017-09-11 Impact factor: 5.691
Authors: A Minematsu; T Hanaoka; D Takeshita; Y Takada; S Okuda; H Imagita; S Sakata Journal: J Musculoskelet Neuronal Interact Date: 2017-03-01 Impact factor: 2.041
Authors: Pamela S Hinton; Laura C Ortinau; Rebecca K Dirkes; Emily L Shaw; Matthew W Richard; Terese Z Zidon; Steven L Britton; Lauren G Koch; Victoria J Vieira-Potter Journal: Bone Rep Date: 2018-05-18
Authors: Rebecca K Dirkes; Matthew W Richard; Grace M Meers; Dustie N Butteiger; Elaine S Krul; John P Thyfault; R Scott Rector; Pamela S Hinton Journal: Curr Dev Nutr Date: 2018-04-17