THE EFFECT OF GYNECOLOGICAL RISK-FACTORS ON LUMBAR AND FEMORAL BONE-MINERAL DENSITY IN PERIMENOPAUSAL AND POSTMENOPAUSAL WOMEN

The relationship between gynecological history and bone mineral densit y (BMD) of the lumbar spine and femoral neck was studied in 3126 perim enopausal women. The study population was a random, stratified sample of participants, selected from the Kuopio Osteoporosis Study, which co nsisted primarily of all 14 220 women aged 47-56 years in Kuopio Provi nce in 1989. After exclusion of 1521 women reporting past or present h ormonal replacement therapy (HRT), 1605 women formed the final study p opulation. Present HRT users had significantly higher lumbar BMD but n ot femoral BMD, than non-hormone users. Postmenopausal status, late me narche, and bilateral oophorectomy were risk factors for low BMD. Prot ective factors against low BMD were increased body weight, increased n umber of pregnancies, as well as hysterectomy without bilateral oophor ectomy, The majority (43.8%) of these operations had been performed du e to the presence of leiomyomas. No significant correlation was found between nulliparity, breast-feeding or amenorrhea before the age of 30 and BMD. In the multiple regression analysis, gynecological variables could account for only 18.4-26.8% of the variance in BMD, while time since last periods, age, age at menarche, weight and hysterectomy were the most significant variables. We conclude that reproductive history gives rise to some special risk groups, to whom BMD measurements and osteoporosis prevention efforts should be directed. However, it is imp ossible to predict BMD by gynecological characteristics.