Endocrine Abstracts

Introduction: Type 1 diabetes secondary osteoporosis is an underdiagnosed condition and there are few studies that addressed the topic of clinical risk factors in this context, although, for a better diagnosis and management, it is of great importance to find such predictors.

Aim: To evaluate bone mineral density and parameters of bone metabolism in patients with type 1 diabetes in comparison with a group of healthy subjects and to determine possible risk factors for osteoporosis in the context of type 1 diabetes.

Patients and methods: 102 patients with type 1 diabetes and 59 healthy controls (pre-menopausal women and men, aged between 20 and 55 years), matched by age, sex, and BMI were included in the study. All subjects with secondary causes of osteoporosis except type 1 diabetes and diabetic patients with stage 3 nephropathy or more (GFR <60 ml/min per 1.73 m²) were excluded. Their lifestyle, personal and parental history were evaluated with a questionnaire, anthropometric measurements were made and DXA osteodensitometry was performed. Serum osteocalcin, intact PTH, 25(OH) vitamin D, total calcium, phosphorus and magnesium were determined.

Results: The risk for low BMD (at least a Z score equal or lower than −2.0 S.D. at any site) was 1.2 higher in type 1 diabetes (95% CI 0.43–3.33), however BMD was not significantly different between patients and controls (P=0.88 for lumbar spine and 0.56 for femoral neck).Type 1 diabetic patients had a median age of 28 and a median disease duration of 11.5 years. Median HbA1c was 8.1%. BMD for a disease duration over 10 years was significantly lower than that for 0.5-5 years (P=0.008, ANOVA). Diabetic nephropathy (stages 1 and 2) increased the risk for low BMD and was associated with a significant rise of PTH. Age was negatively associated with lumbar spine BMD and positively with PTH. BMI was positively associated with BMD at all sites.

Conclusions: The most important predictors for osteoporosis in our study were type 1 diabetes duration (over 10 years) and the presence of diabetic nephropathy. Age towards the upper limit of inclusion (i.e. 55 years old) or low BMI values (low/low normal) may complete an indication for performing DXA in type 1 diabetic patients. Long-term lifestyle measures that we found to be protective for osteoporosis were: avoiding coffee and alcohol consumption, regular exercise and an optimal metabolic control of diabetes.

Disclosure: This work was supported by the European Social Fund POSDRU 107/1.5/S/78702 project.