Bone health in type 1 diabetes : focus on evaluation and treatment in clinical practice

Introduction: Type 1 diabetes (T1D) is an autoimmune disease with chronic hyperglycemic state, which incidence has been globally rising during the past decades. Besides the well-known diabetic complications such as retinopathy, nephropathy and neuropathy, T1D is characterized also by poor bone health. The reduced bone mineralization, quality and strength lead to vertebral and hip fractures as the most important clinical manifestations. Suppressed bone turnover is the main characteristic of T1D-associated bone disorder. Results: This is thought to be due to hyperglycemia, hypoinsulinemia, autoimmune inflammation, low levels of insulin-like growth factor-1 and vitamin D. Young age of T1D manifestation, chronic poor glycemic control, high daily insulin dose, low body mass index, reduced renal function and the presence of diabetic complications are clinical factors useful for identifying T1D patients at risk of reduced bone mineral density. Although the clinical risk factors for fracture risk are still unknown, chronic poor glycemic control and the presence of diabetic complications might raise the suspicion of elevated fracture risk in T1D. In the presence of the above-mentioned risk factors, the assessment of bone mineral density by dual-energy X-ray absorptiometry and the search of asymptomatic vertebral fracture by vertebral fracture assessment or lateral X-ray radiography of thorax-lumbar spine should be recommended. Conclusion: There is no consensus about the treatment of diabetic bone disorder. However, the improvement of glycemic control has been suggested to have a beneficial effect on bone in T1D. Recently, several experiments showed promising results on using anabolic pharmacological agents in diabetic rodents with bone disorder. Therefore, randomized clinical trials are needed to test the possible use of the bone anabolic therapies in humans with T1D

Low bone mineral density and its predictors in type 1 diabetic patients evaluated by the classic statistics and artificial neural network analysis

OBJECTIVE - To investigate factors associated with bone mineral density (BMD) in type 1 diabetes by classic statistic and artificial neural networks. RESEARCH DESIGN AND METHODS - A total of 175 eugonadal type 1 diabetic patients (age 32.8 \ub1 8.4 years) and 151 age- and BMI-matched control subjects (age 32.6 \ub1 4.5 years) were studied. In all subjects, BMI and BMD (as Z score) at the lumbar spine (LS-BMD) and femur (F-BMD) were measured. Daily insulin dose (DID), age at diagnosis, presence of complications, creatinine clearance (ClCr), and HbA 1c were determined. RESULTS - LS- and F-BMD levels were lower in patients (20.11 \ub1 1.2 and 20.32 \ub1 1.4, respectively) than in control subjects (0.59 \ub1 1, P 0.67 units/kg, and ClCr <88.8 mL/min. The presence of all of these risk factors had a positive predictive value, and their absence had a negative predictive value for low BMD of 62.9 and 84.2%, respectively. Data were also analyzed using the TWIST system in combination with supervised artificial neural networks and a semantic connectivity map. The TWIST system selected 11 and 12 variables for F-BMD and LS-BMD prediction, which discriminated between high and low BMD with 67 and 66% accuracy, respectively. The connectivity map showed that low BMD at both sites was indirectly connected with HbA1c through chronic diabetes complications. CONCLUSIONS - In type 1 diabetes, low BMD is associated with low BMI and low ClCr and high DID. Chronic complications negatively influence BMD

Prevalence of morphometric vertebral fractures in patients with type 1 diabetes

OBJECTIVESeveral studies showed low bone mineral density (BMD) and elevated risk of symptomatic fractures in patients with type 1 diabetes (T1D). To our knowledge, there has been no investigation on the prevalence of asymptomatic vertebral fractures (VFx) in T1D. In the current study, we assessed BMD and the prevalence of VFx in T1D.RESEARCH DESIGN AND METHODSWe evaluated 82 T1D patients (26 males and 56 females, aged 31.1 \ub1 8.6 years, BMI 23.5 \ub1 3.3 kg/m(2), disease duration 12.8 \ub1 8.3 years) and 82 controls (22 females and 60 males, aged 32.9 \ub1 5.8 years, BMI 23.9 \ub1 4.8 kg/m(2)). Spinal and femoral BMD (as Z-score, Z-LS and Z-FN, respectively) and the prevalence of VFx were evaluated by dual X-ray absorptiometry.RESULTST1D patients had lower Z-LS and Z-FN than controls (-0.55 \ub1 1.3 vs. 0.35 \ub1 1.0, P < 0.0001, and -0.64 \ub1 1.1 vs. 0.29 \ub1 0.9, P < 0.0001, respectively) and a higher prevalence of VFx (24.4% vs. 6.1%, P = 0.002). Age, diabetes duration, age at diabetes manifestation, glycosylated hemoglobin, Z-LS, Z-FN, and the prevalence of chronic complications were similar for patients with and without VFx. In the logistic regression analysis, the presence of VFx was associated with the presence of T1D but not with lumbar spine BMD. Whereas moderate or severe VFx was associated with low lumbar spine BMD in the whole combined group of T1D patients and controls, there was no association between moderate or severe VFx and lumbar spine BMD in the T1D group.CONCLUSIONST1D patients have low BMD and elevated prevalence of asymptomatic VFx, which is associated with the presence of T1D independently of BMD