Bone mineral density in healthy Dutch women: spine and hip measurements using dual-energy X-ray absorptiometry.

OBJECTIVE

To investigate in healthy normal Dutch women the age-associated changes in bone mineral density (BMD) and the effect on bone mass of the menopause and potential risk factors.

METHODS

In 260 healthy Dutch women BMD was measured in the lumbar spine and three regions of the proximal femur (Ward's triangle, femoral neck and trochanter), using dual energy X-ray absorptiometry (DXA). The subjects were interviewed using a structured questionnaire on age, reproductive history and gynaecological status, height, weight and consumption of tobacco and alcohol.

RESULTS

In 125 premenopausal women a small age-related bone loss was observed at both the lumbar spine and proximal femur, while in postmenopausal women (n = 135) a 2-3 times higher age-related loss was observed. Expressed in years since the menopause this postmenopausal loss was found to be exponential (p < 0.001). After adjustment for age there appears to be a relationship between actual age of menopause and BMD at the lumbar spine and femoral neck. After adjustment for age and actual age of menopause we observed a small negative effect of breastfeeding, whereas parity, current alcohol use and smoking showed no additional effect on BMD in this cohort. For all women (n = 260) a highly significant correlation between BMD and body mass index was found.

CONCLUSIONS

In healthy Dutch women we observed a small premenopausal and an accelerated postmenopausal bone loss in both the lumbar spine and proximal femur. Except for breastfeeding, no other risk factors could be identified.