Prevalence of low central bone mineral density in a Bulgarian female referral population: a pilot study

Prevalence of low bone mineral density at axial sites and fracture risk in Bulgarian population

Background

Osteoporosis is a common chronic disease characterized by low bone mineral density (BMD) and microarchitectural deterioration of the bone, which are associated with increased risk of fragility fractures. Currently the most popular tool is the fracture risk assessment model FRAX to calculate the 10-year probability of major osteoporotic fractures (MOF) and hip fractures (HF).

Objective

To investigate the prevalence of low BMD at axial sites and fracture risk in Bulgarian population.

Methods

We retrospectively analyzed dual energy X-ray absorptiometry (DXA) scan results of 12 478 subjects. Scan results included BMD and T-score assessments of lumbar spine and femoral neck. FRAX major osteoprotic fracture (MOF) and FRAX hip fracture (HF) were assessed in subjects between 40 and 90 years using BMD values.

Results

Of total 12478 subjects, 12119 were women and 359 were men. The mean age of the subjects was 61 years (yrs.) ± 10 yrs. The overall prevalence of low BMD at the lumbar spine was 6084/9336 subjects (65.2%). 3502/9336 subjects (37.5%) were considered as osteopenic and 2582/9336 subjects (27.7%) were considered as osteoporotic. The overall prevalence of low BMD at the femoral neck was 2036/3140 (64.8%). 1641/3140 subjects (52.3%) were classified as osteopenic and 395/3 140 subjects (12.6%) were classified as osteoporotic. The mean values of FRAX MOF and FRAX HF increased significantly with increasing the age interval.

Conclusion

This study is the largest epidemiological research in Bulgaria up to date about the prevalence of low BMD at axial sites.

Femoral neck bone mineral density and 10-year absolute fracture risk in a national representative sample of Bulgarian women aged 50 years and older

This study explored the epidemiology of osteoporosis in Bulgarian women (>50 years). Of the women included in the study, 16.8% had osteoporosis and 46.5% had osteopenia at the femoral neck. The mean 10-year absolute fracture risk was 13.4 ± 9.2% (major fractures) and 2.8 ± 5.2% (hip fractures). This study is the largest Bulgarian epidemiological osteoporosis trial.

PURPOSE

The aim of this study was to determine the prevalence of the major risk factors for osteoporosis and the 10-year absolute fracture risk in a national representative sample of Bulgarian women aged 50 and older.

METHODS

This work is a part of the Bulgarian Osteoporosis Epidemiology Study. The National Statistical Institute selected a national representative epidemiological sample. A questionnaire was used allowing fracture risk calculation according to FRAX. Ten osteoporosis centers throughout the country participated. Bone mineral density (BMD) was measured at the femoral neck by dual X-ray absorptiometry. The statistical analysis was performed on a SPSS 13.0 for windows platform.

RESULTS

A total of 1,331 women were included (mean age 63.8 ± 8.3 years), divided into decades. Of them, 16.8% had osteoporosis and 46.5% had low femoral neck BMD. Their mean 10-year absolute fracture risk for major fractures was 13.4 ± 9.2%, and for hip fractures 2.8 ± 5.2%, respectively. The prevalence of some major risk factors for osteoporosis was as follows: height loss > 3 cm-33.1% of all women; family history of hip fractures-4.1%; previous hip fractures-1.9%; previous vertebral fractures-2.3%; all fractures-23.3%; smoking-11.9%.

CONCLUSIONS

This study is the largest epidemiological osteoporosis trial in Bulgaria to date and allows assumptions about the prevalence of osteoporosis and fractures among women aged 50 and older in our country.