Bone mineral density of the spine and femur in a group of healthy Moroccan men.

BACKGROUND: Bone mineral density (BMD) measurements using dual-energy X-rays absorptiometry (DXA) are widely used to diagnose osteoporosis and to assess its severity. Previous studies show the necessity to establish reference data for bone mass measurements for each particular population. Such data are lacking for the male Moroccan population. AIM: To establish reference values for the healthy Moroccan male population and to compare them with those for Caucasian and Arab males, and to study the impact of different curves implemented in the DXA system on the diagnosis of osteoporosis. METHODS: A cross-sectional study of 592 Moroccan men, recruited from the area of Rabat, the capital of Morocco, aged between 20 and 79 years was carried to establish reference values of bone mineral density. Measurements were taken at the lumbar spine and proximal femurs using DXA (Lunar Prodigy Vision, GE). The data were compared with published normative taken by US, European, Iranian, Lebanese, and Saudi men over six decades of age. Impact on osteoporosis diagnosis according to the WHO criteria using the personalized curve and US (NHANES), European and Middle-East reference curves (as implemented in the Lunar densitometers) was studied. RESULTS: Our results showed that the Moroccan men showed the expected decline in BMD at both sites with age after peaking at 20-29 years age group. Every anatomical region has a different rate of bone loss: lumbar spine (0.3% per year) femoral neck (0.6%), trochanter (0.3%), and total hip (0.4%). The lumbar spine and femoral subregions BMD exhibited increases from 0.3 to 0.5% per kilogram of body weight. In the spine, the US/European Lunar reference values classified a larger proportion of men as osteoporotic (18.1% vs. 7.4%) while using the Arabic Lunar reference values, only 7.8% were classified as osteoporotic. However, using Arabic curve for the femurs resulted in underdiagnosis of osteoporosis (1.8% vs. 6.0%), whereas the US/European Lunar reference values classified men as osteoporotic in 3.9% and 5.3% respectively. DISCUSSION: In comparison with the other Countries, the spine BMD of Moroccan men were slightly lower than Iranian's, Europeans and Brazilians but higher than the Saudi and Lebanese males. We found BMD values taken at the lumbar spine to be around 4% lower than European values between ages 50 and 59 years, and 10% lower for older subjects. These values were 4-6% higher than Saudis/Lebanese values between ages 20-39. For older subjects, Moroccan values were more than 10% higher than Saudis and almost similar to Lebanese. Femoral neck BMD values were 8% higher in young adults (age 20-39 years) to US/Saudis/Lebanese values, but about 10% lower in ages over 60 to US values whereas it was similar to Saudis and Lebanese values. CONCLUSION: Our study emphasises the importance of using population-specific reference values for BMD measurements to avoid over or underdiagnosis of osteoporosis.

Vertebral fracture assessment in healthy men: prevalence and risk factors.

INTRODUCTION: Vertebral fracture assessment (VFA) is a technology that can reliably and accurately diagnose vertebral fractures with greater patient convenience, less radiation exposure, and lower cost than standard spine radiography. OBJECTIVE: To study prevalence and risk factors of vertebral fractures using VFA in healthy men. METHODS: The study cohort consists of a population of 216 healthy men aged between 50 and 79 (mean age, weight and BMI of 63.8 years, 73.3 kg and 25.7 kg/m2, respectively). Lateral VFA images and scans of the lumbar spine and proximal femur were obtained by two technologists using a GE Healthcare Lunar Prodigy densitometer. Vertebral fractures were defined using a combination of Genant semiquantitative (SQ) approach and morphometry. RESULTS: Ninety-three percent of vertebrae from T4-L4 and 98% from T8-L4 were adequately visualized on VFA. Vertebral fractures were detected in 29.6% (64/216) of these men: 34/216 (15.7%) had grade 1 and 30/216 (13.8%) had grades 2 or 3. Twenty one of men with VFA-identified fracture (32.8%) had only a single vertebral fracture, while the other 67.2% had two or more. Fractures were most common in the mid-thoracic spine and at the thoraco-lumbar junction. As would be expected, the prevalence of VFA-detected fractures increased with age and as BMD declined. This group of men had a statistically significant lower weight, height, calcium consumption and T-score than those without a VFA-identified vertebral fracture. Regression analysis showed that presence of vertebral fracture was mainly related to the osteoporotic status (OR: 9.0; 95% CI: 3.5-22.8). CONCLUSION: VFA allows evaluation of the majority of vertebral bodies in men. Vertebral fractures are common in healthy men and are related to low BMD.