Can a determination of tartrate-resistant acid phosphatase predict postmenopausal loss of bone mass?

BACKGROUND

A study was carried out over a 24-month interval to determine if an initial measurement of serum tartrate-resistant acid phosphatase would be predictive of bone mass loss quantified by dual-energy X-ray absorptiometry, as total bone mineral content and total bone mineral content corrected for weight.

DESIGN

Sixty-two women were studied (at onset: mean age 59.7 +/- 8.9 years, 10.8 +/- 8.8 years since menopause; at conclusion: mean age 61.9 +/- 8.8 and 13.0 +/- 8.7 since menopause).

RESULTS

A paired Wilcoxon test showed a small, but significant, increase in weight (P < 0.05) and decrease in height (P < 0.05). Total bone mineral content and total bone mineral content corrected for weight decreased (P < 0.005 and 0.0001, respectively). Serum tartrate-resistant acid phosphatase increased (P < 0.005). Single-regression analysis showed that the per cent bone mass loss observed between the first and second body bone mineral content measurements correlated negatively with the first serum tartrate-resistant acid phosphatase determination (r = -0.62, P < 0.0001). Changes in tartrate-resistant acid phosphatase correlated negatively with changes in total bone mineral content (r = -0.79, P < 0.0001). In a multiple regression analysis of per cent change in bone mass against initially important variables such as age, years since menopause, weight, and tartrate-resistant acid phosphatase, only tartrate-resistant acid phosphatase was significant (P < 0.0001). The sensitivity and specifity of tartrate-resistant acid phosphatase for evaluating bone loss were 86% and 78%, respectively, and the area under the curve was of 0.83 (95% CI 0.71-0.95).

CONCLUSION

These results show that a simple measurement of serum tartrate-resistant acid phosphatase can help to predict the potential rate of bone mass loss in women.