Open AccessBone Strength/Bone Mass Discrepancy in Glucocorticoid‐Treated Adult Mice
Author(s) -
Dubrovsky Alanna M.,
Nyman Jeffrey S.,
Uppuganti Sasidhar,
Chmiel Kenneth J.,
Kimmel Donald B.,
Lane Nancy E
Publication year - 2021
Publication title -
jbmr plus
Language(s) - English
Resource type - Journals
ISSN - 2473-4039
DOI - 10.1002/jbm4.10443
Subject(s) - glucocorticoid , femur , methylprednisolone , cortical bone , medicine , bone density , endocrinology , bone mass , analysis of variance , chemistry , osteoporosis , surgery , anatomy
Glucocorticoids increase bone fragility in patients in a manner that is underestimated by bone mass measurement. This study aimed to determine if the adult mouse could model this bone strength/bone mass discrepancy. Forty‐two 13‐week‐old BALB/cJ mice were randomized into vehicle and glucocorticoid groups, implanted with vehicle or 6‐methylprednisolone pellets, and necropsied after 60 and 120 days. Bone strength and bone mass/microarchitecture were assessed at the right central femur (CF; cortical‐bone–rich) and sixth lumbar vertebral body (LVB6; trabecular‐bone–rich). Bound water (BW) of the whole right femur was analyzed by proton‐nuclear magnetic resonance ( 1 H‐NMR) relaxometry. Data were analyzed by two‐factor ANOVA with time (day 60 and day 120) and treatment (vehicle and glucocorticoid) as main effects for all data. Significant interactions were further analyzed with a Tukey's post hoc test. Most bone strength measures in the CF were lower in the glucocorticoid group, regardless of the duration of treatment, with no time × treatment interaction. However, bone mass measures in the CF showed a significant time × treatment interaction ( p = 0.0001). Bone strength measures in LVB6 showed a time × treatment interaction ( p < 0.02) such that LVB6 strength was lower after 120 days of glucocorticoids compared with 120 days of vehicle treatment. Whole‐femur–BW was lower with both glucocorticoid treatment ( p = 0.0001) and time ( p < 0.02), with a significant time × treatment interaction ( p = 0.005). Glucocorticoid treatment of male BALB/cJ mice resulted in the lowering of bone strength in both cortical and trabecular bone that either appeared earlier or was greater than the treatment‐related changes in bone mass/microarchitecture. The adult mouse may be a good model for investigating the bone strength/mass discrepancy observed in glucocorticoid‐treated patients. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.