Bone mineral density of vertebrae, proximal femur and os calcis in normal Greek subjects as assessed by dual-energy X-ray absorptiometry: Comparison with other populations

Dual energy X-ray absorptiometry (DXA) is an established method for the detection of even small changes in bone mineral density (BMD). It thus allows the earliest possible diagnosis of osteopenia, with consequent prompt estimation of fracture risk. However, for proper evaluation of densitometry results it is essential that a comparison with reference BMD values of normal age- and sex-matched persons from the same population be performed. For this purpose we determined bone density of the L2-L4 vertebrae, the L3 vertebra in the lateral projection, the proximal femur and the os calcis in a cross-sectional study of 168 men and 244 women from the Greek population. The age range of the subjects was 20-80 years. Peak bone mass for both sexes was attained in the 30-35 year age group for the vertebrae and in the 25-30 year age group for the proximal femur and os calcis. Mean annual vertebral bone loss calculated on cross-sectional data ranged from 0.1% to 0.22% for women < 50 years and from 1.3% to 1.6% for those > 50 years, whereas in men the range was from 0.36% to 0.64% for the whole age spectrum. Regarding femoral neck, the values were 0.3% (women < 50 years), 1.2-1.5% (> 50 years) and 0.6-0.8% for men. Total bone loss between ages 20 and 70 was 29.5% for the vertebrae and 32% for the femoral neck in women, whereas the values for men were 19.5% and 29% respectively. A positive correlation was observed between bone density, body weight and body height in both sexes. Body mass index correlated significantly with density only in postmenopausal women. Compared with North American, Finnish and German populations, Greek men presented with lower BMD values in the decades above 40 years. Greek women exhibited lower vertebral BMD values than those from the USA, Germany and Japan (50-60 age group), whereas they did not differ from those of Finnish women. However, femoral neck BMD in Greek women was higher than in Japanese women in all age groups.