osteoporosis
Conditions
Interventions
None listed
Sponsors
Erasmus MC, Universitair Medisch Centrum Rotterdam
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: All Rotterdam Study participants
Exclusion criteria
Exclusion criteria: none
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The main outcome measure by the device is volumetric bone mineral density (vBMD) expressed in mg/cm2. To measure vBMD one needs to consider that bone consists of an organic and a mineral phase. About 38% of bone volume consists of hydroxyapatite and about 62% consist of collagen. The density of hydroxapatite is 3.2 g/cm³, the density of collagen is about 1.1 g/cm³. The density proportion of mineral is therefore 3.2*0.38 = 1.2 g/cm³, for collagen it is 0.68 g/cm³. Adding both yields a material density of 1.9 g/cm³. The calibration of the machine accounts only for the mineral portion. Therefore the measured material density of bone is about 1.2 g/cm³. In addition, vBMD can be measured for the trabecular and cortical compartments of the cross section. Trabecular density is defined as the mass of trabecular bone divided by endosteal volume, i.e. including bone marrow. Since cortical bone is composed to 90 - 98% of bone material and 2 - 10% of osteons, the measured cortical density is 90 - 98% of the material density. | — |
Secondary
| Measure | Time frame |
|---|---|
| Estimation of bone bending strength indexes: the SSI is directly proportional to the fracture load in a three-point bending test. If material properties and the geometry are known, the fracture load can be calculated according to the following formula: FB=4sB*SSI/l. In addition values for muscle- and fat areas are also calculated in the scans. The ratio of cortical to muscle area (bone-muscle ratio) should be around 5% if the adaptation of bone to the muscle force is normal. Lower values might indicate a disturbance of this adaptation process. The Rotterdam Study withholds a very rich set of additional measurements and information collected from the participants, general practitioners and pharmacies that will allow studying diverse outcomes and with the ability to correct for a vast set of confounders. | — |
Countries
Netherlands
Outcome results
None listed