PURPOSE Accumulating evidence has shown a close connection between hematopoiesis and bone formation. Our aim was to evaluate the association between peripheral blood cell counts and bone mineral density (BMD) in a sample of postmenopausal women.

MATERIALS AND METHODS Three hundreds thirty eight healthy postmenopausal women who underwent BMD measurement during their health check-up were investigated. BMD was measured by dual energy X-ray asorptiometry at L1-L4 spine, femoral neck and total proximal femur. BMD was expressed as a T-score: among T-scores obtained from three different sites (L1-L4 spine, femoral neck and total proximal femur), the lowest T-score was considered to be the subject's T-score.

RESULTS The prevalence of osteopenia and osteoporosis diagnosed by T-score in the study participants were 49.4% (167/338) and 5.0% (17/338), respectively. Peripheral blood white blood cell (WBC), red blood cell (RBC) and platelet counts had significant positive correlations with T-scores (p<0.001) upon simple linear regression analysis. A multiple linear regression analysis, after controlling of confounders including age, body weight, systolic blood pressure, alkaline phosphatase and creatinine, showed that WBC (β=0.127; standard error=0.043; p=0.014), RBC (β=0.192; standard error=0.139; p<0.001) and platelet (β=0.097; standard error=0.001; p=0.050) counts still had significant positive association with T-scores.

CONCLUSION The study results showed a positive relationship between blood cell counts and bone mineral density in postmenopausal women, supporting the idea of a close connection between hematopoiesis and bone formation. The study results also suggest that blood cell counts could be a putative marker for estimating BMD in postmenopausal women.