Determinants of Bone Material Strength and Cortical Porosity in Patients with Type 2 Diabetes Mellitus

Abstract

Context Reduced bone material strength index (BMSi) and increased cortical porosity (CtPo) have emerged as potentially contributing to fracture risk in type 2 diabetes mellitus (T2DM) patients. Objective Determine whether BMSi or CtPo are related to other diabetic complications. Design Cross-sectional observational study. Setting Subjects recruited from a random sample of southeast MN residents. Participants 171 T2DM patients (mean age, 68.8 years) and 108 age-matched non-diabetic controls (mean age, 67.3 years). Main Measures BMSi measured using microindentation, skin advanced glycation end-products (AGEs) measured using autofluorescence, high-resolution peripheral quantitative computed tomography at the distal radius and tibia, assessment of diabetic microvascular complications including urine microalbuminuria, retinopathy, neuropathy, and vascular disease (ankle brachial index, and transcutaneous oxygen tension [TcPO2]). All analyses were adjusted for age, sex, and body mass index. Results Skin AGEs were negatively correlated with BMSi in both T2DM (r= -0.30, p < 0.001) and control (r= -0.23, p = 0.020) subjects. In relating diabetic complications to CtPo, we found that T2DM patients with clinically significant peripheral vascular disease (TcPO2 ≤ 40 mm Hg) had higher (+21.0%, p = 0.031) CtPo at the distal tibia as compared to controls; in these subjects, CtPo was negatively correlated with TcPO2 at both the distal tibia (r = -0.39, p = 0.041) and radius (r = -0.41, p = 0.029). Conclusions Our findings demonstrate that bone material properties are related to AGE accumulation regardless of diabetes status, while CtPo in T2DM patients is linked to TcPO2, a measure of microvascular blood flow.

Increased Cortical Porosity, Reduced Cortical Thickness, and Reduced Trabecular and Cortical Microhardness of the Superolateral Femoral Neck Confer the Increased Hip Fracture Risk in Individuals with Type 2 Diabetes

“…When scientific community has become aware of the increased fracture risk in T2DM individuals, one more challenge appeared. Namely, it has been shown that dual-energy X-ray absorptiometry (DXA) is not a sufficiently reliable tool to predict the fracture risk in T2DM since bone mineral density (BMD) has often been reported to be equally good [ 4 ] as in controls or even higher [ 5 ]. Since BMD does not reliably predict the fracture risk, examination of bone microarchitecture was a natural approach to further understand the origins of the increased fracture risk in T2DM.…”

“…Since BMD does not reliably predict the fracture risk, examination of bone microarchitecture was a natural approach to further understand the origins of the increased fracture risk in T2DM. High-resolution peripheral quantitative computed tomography (HR-pQCT) has frequently been used for the assessment of bone microarchitecture at distal tibia and radius [ 5 – 9 ]. While increased cortical porosity in T2DM is often found in these clinical studies of bone microarchitecture, this is not a consistent finding, particularly in T2DM subjects without microvascular disease [ 5 , 7 ].…”

Imaging techniques to study diabetic bone disease

“…The combination of obesity and T2D was found to be associated with greater trabecular separation at the distal radius and tibia, and lower failure load and stiffness at the distal tibia, compared to men with obesity without T2D. While Samakkarnthai et al investigated the associations of bone material strength index (BMSi) at the anterior midtibia and HR-pQCT-derived cortical porosity at the distal radius and tibia with skin advanced glycation endproducts (AGEs) measured using autofluorescence, and diabetic microvascular complications including urine microalbuminuria, retinopathy, neuropathy, and vascular disease in 171 subjects with T2D (age ¼ 68.8 AE 7.6 years) and 108 age-matched controls with no diabetes (age ¼ 67.3 AE 8.8 years) [34]. In analyses adjusted for age, sex, and BMI, skin AGEs were significantly negatively correlated with BMSi in both groups, and subjects with T2D and peripheral vascular disease had significantly higher cortical porosity at the distal tibia compared to controls.…”

Critical review of bone health, fracture risk and management of bone fragility in diabetes mellitus

“…Diabetes-related vascular changes (cortical microangiopathy) had been postulated as the reason behind the poor cortical bone quality in diabetic patients with a fracture[ 55 ]. Moreover, cortical porosity was significantly higher in T2DM patients with peripheral vascular disease in comparison to controls, and cortical porosity was inversely correlated with transcutaneous oxygen tension[ 56 ]. On the other hand, in the Maastricht Study[ 57 ], T2DM patients with HbA1c <7% have superior cortical bone quality than those with poor glycemic control, but no significant relation was found with the microvascular disease.…”