Structural and Component Alterations in Intertrochanteric Crests of Femur in Induced Short- and Long- Term Diabetes

Abstract

Individuals with type I diabetes mellitus have an increased risk of proximal femoral fracture. Moreover, low bone mineral density (BMD), altered serum levels of biomarkers of bone turnover and altered bone morphometry parameters, which affect bone strength, are observed in individuals with diabetes. Thus, this study aimed to compare the components of the intertrochanteric crest of the femur in terms of morphology, bone volume fraction (BV/TV), BMD, trabecular thickness (Tb.Th), and separation (Tb.Sp) by using microcomputed tomography, histomorphology, the determination of cell numbers, and the quantification of empty lacunae and collagen fibres via light microscopy in rats with both short- and long-term streptozotocin-induced diabetes. During both the early and late stages of diabetes, reductions in the femoral BV/TV, BMD, and Tb.Th values and an increase in the Tb.Sp value were observed; moreover, the numbers of osteoblasts and osteocytes decreased, but the numbers of empty lacunae and osteoclasts increased. Additionally, disorganized collagen fibres with lower density were observed in the two diabetes groups. The severity of these changes was more pronounced in the long-term diabetes model, along with thickening of blood vessels and an increased bone marrow adipocyte tissue. All of these changes lead to a decrease in bone quality and fragility, which might be related to an increased risk of femoral fractures in the diabetes groups. Thus, the current understanding of the bone damage that occurs during the development of diabetes might warrant careful consideration of bone strength during the early stages of the disease.