Discordance in diagnosis of osteoporosis using spine and femur bone densitometry: prevalence and related factors

ABSTRACT

This study was conducted to evaluate prevalence and risk factors for diagnostic discordance for osteoporosis due to different T-scores of lumbar spine and femoral neck. In this cross sectional study demographic, anthropometric and risk factors for osteoporosis were derived from a database on 3,039 post-menopausal women who underwent bone densitometry for the first time in our department [Kurdistan Nuclear Medicine Center] from 2003 to 2010. DXA was performed on L2-L4 vertebrae and femoral neck for all cases. Major discordance [one site osteoporotic and the other normal] and minor discordance [difference between two site no more than one WHO diagnostic class] were determined. The association of related risk factors with discordance of interest was assessed. Prevalence of osteoporosis and osteopenia in these post-menopausal women with mean age of 58.5 +/- 8.7 years, menopausal period of 11.2+9.4 years and mean BMI of 28+4.5 were 37.7% and 50.7%, respectively. Frequencies of minor and major discordances were 40.0% and 1.8%, respectively. The minor discordance was a common finding; however, the major discordance is uncommon. The most important risk factors for major discordance were age, menopausal duration and BMI. There was no significant relationship between other risk factors [smoking and history of bone fracture] and diagnostic T-score discordances