The serum insulin-like growth factor-binding protein-2 ratio in postmenopausal women with osteoporosis was significantly higher (p < 0.02) than that in normal healthy postmenopausal women, but the serum insulin-like growth factor binding protein-3 ratio in women with osteoporosis was significantly lower (p < 0.01). Here, IGFBP3 is linked to osteoporosis.