Association between respiratory function and osteoporosis in pre- and postmenopausal women

To investigate the relationships between respiratory function and osteoporosis, 132 premenopausal and 98 postmenopausal women were evaluated.

Bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry. Pulmonary function and anthropometric parameters were measured using a spirometer and a body composition analyzer.

Lumbar spine and proximal femur BMDs in postmenopausal women with forced expiratory volume in 1s (FEV1) > or = 92.0% averaged 0.83 +/- 0.12 g/cm2 and 0.67 +/- 0.11 g/cm2, which were significantly above the values (0.76 +/- 0.14 g/cm2 and 0.61 +/- 0.12 g/cm2, P < 0.05) in those with FEV1 <92.0%. The prevalences of osteoporosis at lumbar spine and proximal femur were 59.2 and 46.9% in the postmenopausal women with peak expiratory flow rate (PEFR) <5.12 l/s, significantly higher than those of osteoporosis at the corresponding sites in the women with > or = 5.12 l/s (36.7 and 20.4%, P < 0.05). Lumbar spine and proximal femur BMDs were positively correlated with FEV1 (r = 0.28, P < 0.05; r = 0.31, P < 0.05) and PEFR (r = 0.35, P < 0.05; r = 0.23, P < 0.05) in postmenopausal women; however, no significant correlations were observed in premenopausal women.

Pulmonary function seems to be more closely associated with BMD in postmenopausal women than in premenopausal women. Poor respiratory function may be an indicator of postmenopausal women at increased risk of osteoporosis.