Hyperglycemia compromises Rat Cortical Bone by Increasing Osteocyte Lacunar Density and Decreasing Vascular Canal Volume

Abstract

Uncontrolled diabetes is associated with increased risk of bony fractures. However, the mechanisms have yet to be understood. Using high-resolution synchrotron micro-CT, we calculated the changes in the microstructure of femoral cortices of streptozotocin-induced hyperglycemic (STZ) Wistar Albino rats and tested the mechanical properties of the mineralized matrix by nanoindentation. Total lacunar volume of femoral cortices increased in STZ group due to a 9% increase in lacunar density. However, total vascular canal volume decreased in STZ group due to a remarkable decrease in vascular canal diameter (7 ± 0.3 vs. 8.5 ± 0.4 µm). Osteocytic territorial matrix volume was less in the STZ group (14,908 ± 689 µm3) compared with healthy controls (16,367 ± 391 µm3). In conclusion, hyperglycemia increased cellularity and lacunar density, decreased osteocyte territorial matrix, and reduced vascular girth, in addition to decreasing matrix mechanical properties in the STZ group when compared with euglycemic controls.

The Hyperglycemia and Hyperketonemia Impaired Bone Microstructures: A Pilot Study in Rats

“…Similarly, diabetes deteriorates cortical bone and shortens bone length. Hyperglycemia increases the osteocyte lacunar density by decreasing osteocytic territorial matrix volume, thus increasing cellularity of cortical bone as well as affecting the bone length (27). The STZ-rats displayed an apparently smaller cortical area and a higher cortical porosity (28).…”

Ficus deltoidea promotes bone formation in streptozotocin-induced diabetic rats

“…It has been demonstrated that diabetes is associated with several lower extremities orthopaedic conditions and complications that affect the quality of life (Ay et al. 2020 ). Diabetes accelerates bone loss, osteopenia, and osteoporosis by promoting osteoclast function (Wongdee and Charoenphandhu 2011 ).…”

“…Ay et al. ( 2020 ) reported an increase in cellularity and lacunar density in STZ rats based on information obtained from high-resolution synchrotron micro-CT. However, several important features such as osteoblasts, osteoclasts, resorption lacunae, or osteoid seams on the bone surface cannot be visualised (Burghardt et al.…”

Large-scale quantification of human osteocyte lacunar morphological biomarkers as assessed by ultra-high-resolution desktop micro-computed tomography

“…Specifically, with ultra-high-resolution osteocyte imaging, it is imperative that the lacunar morphometric parameters are well defined and measured accordingly. Great strides have been made towards the standardization of these metrics in recent years, and several studies have explored different basic measures such as lacunar density, shape, and orientation [18,20,21,[29][30][31][32][33][34].…”

“…Specifically, with ultra-high-resolution osteocyte imaging, it is imperative that the lacunar morphometric parameters are well defined and measured accordingly. Great strides have been made towards the standardization of these metrics in recent years, and several studies have explored different basic measures such as lacunar density, shape, and orientation [18, 20, 21, 29–34]. Mader et al have most thoroughly described and validated both simple and abstract lacunar morphometric parameters, and hence this study follows their naming convention and mathematical definitions [18].…”