[Bone densitometry by monochromatic photon absorption. Study of a normal population and values obtained in various...

Monophotonic absorption densitometry of the forearm is an exact method for the evaluation of the bone mineralisation, provided the positioning of the forearm is strictly controlled. It is also able to demonstrate progressive enlargement of the bones with age, up until the ages of about 60 to 70 years. The measurements should be performed in two sites: diaphyseal (cortical bone) and epiphyseal (cortical and trabecular bone). The curves obtained from 1,011 controls are in agreement with the current state of knowledge concerning the variations in bone mass during life in both sexes. In women, the number of pregnancies has no influence on the mineralisation index (MI). The values obtained in 156 osteoporotic patients and in 53 subjects with idiopathic hypercalciuria were appreciably lower than those obtained in age-matched controls. In individual subjects, this method appears to be much more discrimination than the measurement of the trabecular bone volume (TBV) for the diagnosis of osteoporosis and no statistically significant correlation was observed between the MI and the TBV. In male controls, there was a depression of the mean curves around the age of 45 years in all four sites of measurement. This depression was also observed in male subjects with hypercalciuria. They correspond to the generations born between 1930 and 1940. The responsibility of a relative nutritional deficiency affecting growing boys during the 1939-45 war is proposed.