[Lumbar vertebral and femoral neck bone densitometry; site of bone density measurement may affect therapy decision.].
OBJECTIVE
The aim of this study was to compare the results provided by the measurement of vertebral bodies (L:II-IV) and femoral neck bone mineral density (BMD) by dual energy X-ray absorptiometry (DEXA) for assessing the individual risk of osteoporosis.


METHODS
Three-hundred-thirty-one Icelandic women aged 35-65 years who attended the Reykjavik City Hospital Bone Densitometry during the period, 1st of October 1994 - 31st of December 1995, participated in the study. Women who had received hormone replacement therapy or were receiving drugs or had a disease known to affect bone metabolism were excluded. Criteria suggested by WHO were used to categorize women as "at risk" for osteoporosis, bone density >1 standard deviation below the young adult mean (35-40 years in our case) or as "low risk", bone density above this level.


RESULTS
When lumbar vertebral body BMD was used as the primary risk indicator, 18.7% of the women classified as low risk would be at risk if femoral neck BMD was added. Similarly when femoral neck BMD was used as a prime indicator 7.5% of the women classified as low risk would be at risk if lumbar BMD was added.


CONCLUSIONS
These results suggest that both lumbar vertebral and femoral neck measurements should be made when assessing the risk in this age group as an aid in deciding preventive therapy.
Sigurdsson
G
G
Oskarsdottir
D
D