Age-related change of technetium-99m-HMDP distribution in the skeleton.

UNLABELLED

To understand age-related changes of whole-body and regional skeletal metabolism, it is important to investigate the mechanisms of age-related bone loss and to develop suitable treatments for it. Bone biopsies show metabolism of the particular site examined while biochemical markers for bone metabolism reflect total skeletal metabolism. Bone scintigraphy is a convenient and simple way to analyze whole-body and regional skeletal metabolism. We attempted to study and understand age-related changes in bone metabolism by quantifying the bone scan and correlating it with biochemical bone metabolic markers.

METHODS

The whole-body skeletal uptake (WBSU) and tracer distribution pattern were studied in men and women by bone scintigraphy using 99mTc-hydroxy-methane-diphosphonate (HMDP). Bone scans were performed using a standard protocol and quantified by setting regions of interest (ROIs) on selected regions. WBSU and the skeletal distribution pattern were compared with simultaneously obtained serum biochemical markers.

RESULTS

WBSU showed an increase with age in both sexes, but in women, uptake in the head and legs increased more relatively than in the thoracic region, while in men no such tendency was observed. Increase of WBSU and relative increase of uptakes in the head demonstrated a weak correlation with the serum levels of alkaline phosphatase and type 1 collagen metabolites.

CONCLUSION

These results show an age-related increase of skeletal turnover and sex-dependent regional skeletal metabolism. The age-related changes seen in bone scintigrams might be a sign of progressive bone loss, reflecting changes in local bone metabolism.