Resistive exercise in astronauts on prolonged spaceflights provides partial protection against spaceflight-induced bone loss

J Sibonga; T Matsumoto; J Jones; J Shapiro; T Lang; L Shackelford; S M Smith; M Young; J Keyak; K Kohri; H Ohshima; E Spector; A LeBlanc

doi:10.1016/j.bone.2019.07.013

Resistive exercise in astronauts on prolonged spaceflights provides partial protection against spaceflight-induced bone loss

Bone. 2019 Nov:128:112037. doi: 10.1016/j.bone.2019.07.013. Epub 2019 Aug 7.

Authors

J Sibonga¹, T Matsumoto², J Jones³, J Shapiro⁴, T Lang⁵, L Shackelford⁶, S M Smith⁷, M Young⁸, J Keyak⁹, K Kohri¹⁰, H Ohshima¹¹, E Spector¹², A LeBlanc¹³

Affiliations

¹ Human Health & Performance Directorate, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058, USA. Electronic address: [email protected].
² Fujii Memorial Institute of Medical Sciences, University of Tokushima, Tokushima 770-8503, Japan. Electronic address: [email protected].
³ Center for Space Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA. Electronic address: [email protected].
⁴ Department of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA. Electronic address: [email protected].
⁵ Department of Radiology, University of California, San Francisco, CA 94143, USA. Electronic address: [email protected].
⁶ Human Health & Performance Directorate, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058, USA. Electronic address: [email protected].
⁷ Human Health & Performance Directorate, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058, USA. Electronic address: [email protected].
⁸ Human Health & Performance Directorate, NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX 77058, USA. Electronic address: [email protected].
⁹ Department of Radiological Sciences, Department of Mechanical and Aerospace Engineering, Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA. Electronic address: [email protected].
¹⁰ Department of Nephrology, Nagoya City University, Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan. Electronic address: [email protected].
¹¹ Japan Aerospace Exploration Agency, Tsukuba Space Center, 2-1-1 Sengen, Tsukuba-Shi, Ibaraki 305-8505, Japan. Electronic address: [email protected].
¹² KBRwyle, 2400 NASA Parkway, Houston, TX 77058, USA. Electronic address: [email protected].
¹³ Center for Space Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA. Electronic address: [email protected].

PMID: 31400472
DOI: 10.1016/j.bone.2019.07.013

Abstract

Bone loss in astronauts during spaceflight may be a risk factor for osteoporosis, fractures and renal stone formation. We previously reported that the bisphosphonate alendronate, combined with exercise that included an Advanced Resistive Exercise Device (ARED), can prevent or attenuate group mean declines in areal bone mineral density (aBMD) measured soon after ~ 6-month spaceflights aboard the International Space Station (ISS). It is unclear however if the beneficial effects on postflight aBMD were due to individual or combined effects of alendronate and ARED. Hence, 10 additional ISS astronauts were recruited who used the ARED (ARED group) without drug administration using similar measurements in the previous study, i.e., densitometry, biochemical assays and analysis of finite element (FE) models. In addition densitometry data (DXA and QCT only) were compared to published data from crewmembers (n = 14-18) flown prior to in-flight access to the ARED (Pre-ARED). Group mean changes from preflight (± SD %) were used to evaluate effects of countermeasures as sequentially modified on the ISS (i.e., Pre-ARED vs. ARED; ARED vs. Bis+ARED). Spaceflight durations were not significantly different between groups. Postflight bone density measurements were significantly reduced from preflight in the Pre-ARED group. As previously reported, combined Bis+ARED prevented declines in all DXA and QCT hip densitometry and in estimates of FE hip strengths; increased the aBMD of lumbar spine; and prevented elevations in urinary markers for bone resorption during spaceflight. ARED without alendronate partially attenuated declines in bone mass but did not suppress biomarkers for bone resorption or prevent trabecular bone loss. Resistive exercise in the ARED group did not prevent declines in hip trabecular vBMD, but prevented reductions in cortical vBMD of the femoral neck, in FE estimate of hip strength for non-linear stance (NLS) and in aBMD of the femoral neck. We conclude that a bisphosphonate, when combined with resistive exercise, enhances the preservation of bone mass because of the added suppression of bone resorption in trabecular bone compartment not evident with ARED alone.

Keywords: Alendronate; Bone; Densitometry; Finite element modeling; Hip fracture; Osteoporosis.

Published by Elsevier Inc.

Publication types

Clinical Trial
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Absorptiometry, Photon
Adult
Alendronate / therapeutic use
Astronauts
Bone Density / drug effects
Bone Density / physiology*
Bone Diseases, Metabolic / drug therapy
Bone Diseases, Metabolic / prevention & control
Bone Diseases, Metabolic / therapy
Bone and Bones / drug effects
Bone and Bones / physiology
Exercise Therapy / methods*
Humans
Male
Middle Aged
Osteoporosis / drug therapy
Osteoporosis / prevention & control
Osteoporosis / therapy
Space Flight*
Weightlessness / adverse effects

Substances

Alendronate