Microarchitecture, Bone Strength and Fracture Risk in Long-term Type 1 Diabetes

Based on a cross-sectional approach the investigators aim to assess microstructural, biomechanical and densitometric bone characteristics in patients with longstanding type 1 diabetes and age- and sex-matches controls. The investigators examine whether the presence of microvascular disease and/or poor diabetic control is associated with an altered bone microarchitecture and whether any such effect is independent of bone mineral density. Furthermore, the investigators aim to look into the relationship between an altered bone microarchitecture and advanced glycation end product (AGE) formation as well as biochemical markers of bone formation and bone turnover. The study aims to identify type 1 diabetic patients with high fracture risk by assessing the discriminatory power of parameters of cortical and trabecular microstructure measured via high resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius and tibia and high resolution quantitative computed tomography (HR-QCT) of the proximal femur and tibia with and without adjustment for bone density.

Inclusion criteria

• women and men with longstanding type 1 diabetes (age 40-80 years, BMI 18-37 kg/m2 and age- and sex matched non-diabetic controls
• presence of type 1 diabetes for at least 25 years (defined by history of Insulin treatment)

Exclusion criteria

• Patients unable to give written informed consent, e.g. with severe dementia or patients not understanding German (or other local language)
• Any medical or psychiatric condition which would preclude the participant from adhering to the protocol
• Idiopathic or premenopausal osteoporosis or coexisting metabolic bone disease (e.g. Paget´s disease, primary hyperparathyroidism)
• Previous treatment with osteoporosis medication (bisphosphonates, denosumab) or intake of medications that are known to affect bone metabolism (e.g. steroids, anticonvulsants) within 6 months prior to enrollment
• Patients with medical conditions known to affect bone health ( e.g. metastatic bone disease, celiac disease, inflammatory bone disease, hypogonadism, thyrotoxicosis, hypercortisolism, chronic kidney disease stage IV and V (KDIGO), liver dysfunction (serum aspartate amino transferase (ASAT) >3 times the upper limit of normal)
• Inability to keep the extremities still for a few minutes of an HR-pQCT examination (e.g. Parkinson disease, spastic syndrome)
• Pregnant or breastfeeding women