[Parity and menarche as risk factors for osteoporosis in postmenopausal women]

Worldwide studies, even in our country, have thrown discrepant results about the relation between osteoporosis, parity and age of menarche.

To investigate the relation of osteoporosis in postmenopausal mexican women with multiparity and age of menarche.

Transversal, retrospective and analytical study. Non-probabilistic sampling technique was performing with users women of the IMSS in San Luis Potosí. Reproductive history and age of menarche were obtained by the addition of these items to the previously validated Albrand questionnaire. Women were divided into groups according to the number of pregnancies in: normal parity (0 to 3 childbirths) conformed by 112 patients (46%) and multiparity (> or = 4 pregnancies), 131 women (54%). In relation to menarche with an average of 12.98 years, from this number we divided them in: early menarche (before the age of 13) and late menarche (at 13 years of age or after). It was measured bone mineral density with dual distal forearm x-ray absorptiometry to all patients.

243 women were studied, with an average of age of 55.92, rank 31 to 80 years. Using the criteria, of the World Health Organization, 18% of posmenopausal women had osteoporosis, 39% had osteopenia and 41% had bone normality. No association was found between the number of deeds and osteoporosis. Additionally we observed that the women who had 4 or more children were older than the other women. average 57.42 against 54.16. Also there was significant negative correlation (r = -0.43) between age and densitometry. In addition we found that an age greater to 13 years in the appearance of the menarche was related to osteoporosis (OR 4.46; p = 0.035).

In posmenopausal women a menarche at the age of 13 years or after is a risk factor for osteoporosis.