Type I Diabetes Mellitus and Insulin Therapy on Bone Microarchitecture, Composition and Mechanical Properties

Abstract

Background: The aim of this study was to evaluate the microarchitecture, composition and mechanical properties of cortical bone of rats with type I diabetes mellitus (TIDM) and submitted to insulin therapy (IT). Methods: Thirty rats were divided into three groups (n=10): non-diabetic, diabetic and diabetic+insulin. TIDM was induced by intravenous injection of streptozotocin. In diabetic+insulin group, 4IU insulin was administered twice per day (1IU at 7am and 3IU at 7pm). The animals were euthanized five weeks after TIDM induction; the tibiae were removed and submitted to microcomputed tomography (micro-CT, 8µm), fourier transform infrared spectroscopy (FTIR) and dynamic microhardness indentation. Results: Micro-CT analysis showed that diabetic group had lower bone surface/tissue volume ratio (BS/BV) (p=0.018), cortical thickness (Ct.Th) (p<0.001) and degree of anisotropy (Ct.DA) (p=0.034) values compared to non-diabetic group. The diabetic group showed lower Ct.Th than diabetic + insulin group (p=0.018). The non-diabetic group had lower fractal dimension (Ct.FD) values compared to diabetic groups (p<0.001). The ATR-FTIR analyses showed lower values for all measured parameters in the diabetic group than non-diabetic group (amide I ratio: p=0.046; crystallinity index: p=0.038; matrix:mineral ratios - M:MI: p=0.006; M:MIII: p=0.028). The diabetic+insulin group showed a lower crystallinity index (p=0.022) and M:MI ratio (p=0.002) than non-diabetic and diabetic groups, respectively. The diabetic group showed lower Vickers hardness values than non-diabetic (p<0.001) and diabetic+insulin (p=0.003) groups. Conclusion: TIDM negatively affect bone microarchitecture, collagen maturation, mineralization and bone microhardness. Moreover, insulin minimized the effect of TIDM on cortical thickness and organic/mineral matrix.

Normoglycemia partially recovers the disrupted osteoblast differentiation of mesenchymal stem cells induced by type 1 but not type 2 diabetes mellitus

“…Insulin therapy has been shown to reduce the deleterious effects of T1DM on rodent bone tissue. 45 The use of cinaciguat, a nitric oxide-independent activator of oxidized guanylate cyclase, reduced the oxidative stress induced by hyperglycemia and restored the osteoblast differentiation capacity of MSCs derived from mice with T1DM. 12 Clinically, it is possible to speculate that controlling glucose levels in patients with T1DM may help to reverse the bone damage induced by this metabolic disorder.…”

“…Indeed, the recovery of the normoglycemic environment partially restored the ability of MSCs derived from animals with T1DM to differentiate into osteoblasts. Insulin therapy has been shown to reduce the deleterious effects of T1DM on rodent bone tissue 45 . The use of cinaciguat, a nitric oxide‐independent activator of oxidized guanylate cyclase, reduced the oxidative stress induced by hyperglycemia and restored the osteoblast differentiation capacity of MSCs derived from mice with T1DM 12 .…”

Investigation of Fractal Dimension Analysis and Radiomorphometric Indices in Children with Type 1 Diabetes Mellitus

“…This could be because our study was conducted on a pediatric patient group who were diagnosed for the first time and whose treatment has not yet started. In another study (22), it has been found that T1DM affects cortical thickness, fractal size, and bone microhardness, as well as microstructure and composition, and that insulin therapy reduces the effect Iran J Pediatr. 2024; 34(3): e142061.…”