gms | German Medical Science

Objectives: Osteoporosis is a severe disease of the skeleton reducing bone density. Untreated osteoporosis can result in fractures, especially in the hip and spine, eventually resulting in disability, chronic pain, and a reduced quality of life. Its complications can significantly impact overall health and well-being and can be fatal in an indirect way. Therefore, early diagnosis and proactive management are crucial to prevent severe health damage. While osteoporosis can affect both men and women, postmenopausal women and individuals of older age are at higher risk. Other risk factors include low body weight, family history, and lifestyle factors such as smoking and malnutrition. It was shown, that the Calcium isotope marker (CIM) measured in blood serum and/or urine is a new biomarker with high sensitivity and specificity for the body Ca balance. CIM allows for early detection of osteoporosis and can be used to monitor the success of an osteoporosis therapy as well. The aim of the project “Osteo-Frak-Risk” within the framework of the “Blue Health Tech” alliance is to improve existing and develop a more sensitive fracture risk calculator that makes use of the new CIM technology allowing an improved proactive and individualized management of osteoporosis.

Methods: All currently available fracture risk calculators lack CIM integration. A clinical study with 160 participants (women, aged≥60 years, BMI <30 kg/m²) is conducted. After a first screening (V0) bone mineral density (BMD) using DXA and CIM values in serum and urine were measured (V1). Measurement of CIM values in urine and serum will be repeated after one (V2) and two years (V3).

Results and conclusion: Five out of 160 participants did not meet the inclusion criteria and were excluded. For all included subjects (n=155) bone mineral density was measured using DXA. About 30% (n=46) show osteoporotic bone density, 49% show osteopenia and 21% (n=33) have a normal bone density. The first results of CIM measurements show that about 33% of CIM values of both, urine and serum were below threshold values indicating a negative bone Ca balance and were nicely matching the DXA results. Average δ^44/42Ca_serum and δ^44/42Ca_urine is -0.86±0.14‰ (1SD) and 0.24±0.28‰(1SD), respectively. These values were close to the cut-off values discriminating individuals with and without osteoporosis (<-0.85‰ in serum and <0.16‰ in urine).

Initial results of our study confirm previous findings on the potential of calcium isotope measurements. Further data points at V1, V2 and V3 of this study will help to assign a particular fracture risk over time and allow to follow the progression of the diseased bone, which then in turn allows to apply preventive measures.