Lumbar Bone Mineral Density and Insulin-like Growth Factor Binding Protein-3 in Japanese Collegiate Women

The purpose of this study was to investigate the relationship between lumbar bone mineral density (BMD) and insulin-like growth factor binding protein-3 (IGFBP-3) level in 55 collegiate women. In univariate analyses, body weight, body mass index (BMI), waist circumference, maximal oxygen uptake (VO(2)max) in L.min(-1), and IGFBP-3 level were significantly positively correlated, while serum calcium (Ca) level was significantly negatively correlated with lumbar BMD. Multiple regression analysis was performed with lumbar BMD as a dependent variable and body weight, BMI, waist circumference, VO(2)max in L.min(-1), and serum levels of IGFBP-3 and Ca as independent variables. Lumbar BMD was significantly positively correlated with body weight, VO(2)max in L.min(-1), and IGFBP-3 level, while negatively correlated with serum Ca level. The subjects were divided into 3 groups in accordance with IGFBP-3 level. After adjusting for body weight, VO(2)max in L.min(-1), and serum Ca level in the analysis of covariance, the group with the highest IGFBP-3 had significantly higher lumbar BMD than the lowest group. The results indicate that the known association of IGFBP-3 with lumbar BMD in older adults is already apparent in young women.