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

Osteoporosis is one of the most important health problems among elderly women. The prevalence of central osteoporosis in Bulgaria is still unknown. We tried to retrospectively determine the prevalence of osteopenia and osteoporosis at the spine and hip in a female referral population. Bulgarian women (2,600) aged group 25-87 years referred for bone densitometry screening were included. Information about known risk factors for low bone mass was recorded. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (Hologic QDR 4500 A) at the lumbar spine (2,547 participants, 1,954 of whom were postmenopausal) and left hip (723 participants, 605 of whom were postmenopausal). T-scores were calculated from Hologic-provided and own Bulgarian peak BMD data (the latter based on 122 healthy premenopausal 25- to 39-year-old women). Peak lumbar spine BMD was 0.994 g/cm2 (SD 0.095 g/cm2), and thus lower than the manufacturer-provided value of 1.047 g/cm2. The peak BMD of the total hip was 0.959 g/cm2 (SD 0.129 g/cm2) and thus higher than the manufacturer-provided BMD of 0.942. T-scores differed according to the database used. The osteoporosis threshold of -2.5 SD was reached at the spine in the age group 70-74 years. Left hip T-scores showed a much slower decline with age. In women aged 50 and older the prevalence of osteoporosis reached 37.31% at the spine, and 16.14% at the left hip. Osteopenia was found in 39.74% at the spine and in 65.57% at the total hip. This is the first Bulgarian study looking for the prevalence of central osteoporosis in a female referral population. It may become the starting point for future epidemiological work.