Evaluation of bone mineral density and bone strength in autochthonous transgenic model mice for diabetes mellitus (Akita mice)

Abstract

ObjectivesDiabetes mellitus (DM) causes secondary osteoporosis, which reduces bone mineral density (BMD) and bone strength. Akita mice (AM) are DM model mice used to evaluate glucose metabolism. However, bone metabolism in AM remains unclear. The purpose of this study was to evaluate BMD, bone strength, and serum sclerostin levels in AM. MethodsFemale AM and control mice (C57/BL/6NCrSlc; CM) were divided into four groups: (1) a CM group sacrificed at 14 (CM-14w; n = 8) or (2) 18 weeks of age (CM-18w; n = 6); and (3) an AM group sacrificed at 14 (AM-14w; n = 9) or (4) 18 weeks of age (AM-18w; n = 6). Blood glucose level, serum sclerostin level, total tibial BMD, and femoral shaft bone strength were evaluated at each time point. ResultsBlood glucose levels were significantly higher in AM than in CM (p < 0.001). Serum sclerostin levels were significantly lower in AM-18w than in CM-18w (p < 0.001). BMD was significantly lower in AM-14w than in CM-14w (p = 0.004). Stiffness of the femoral shaft was significantly lower in AM-18w than in CM-14w (p = 0.04). Body weight (r = 0.608, p < 0.01) and maximum load (r = 0.438, p < 0.05) were significantly positively correlated with serum sclerostin levels, while blood glucose levels showed a significant negative correlation (r = −0.708, p < 0.01). ConclusionsAM showed decreased BMD and bone strength with lower levels of serum sclerostin than CM.