The influence of pregnancy and selected aspects of female health on skeletal status and fracture incidence in postmenopausal women from the RAC-OST-POL Study.

INTRODUCTION

The postmenopausal bone health reflects the influence of various factors that have been in effect throughout life and hormonal regulation is among them. The aim of the current study is to investigate the effect of pregnancies and other factors related to female reproductive health on bone mineral density and the incidence of fractures in the postmenopausal period.

MATERIAL AND

METHODS

We performed a case-control retrospective analysis in a group of 977 postmenopausal women from the RACOST-POL cohort.

RESULTS

In the study group, there were 894 (91.5%) women who had at least one delivery and breastfeeding was reported by 845 (86.5%) women. Bone mineral density (FN T-score) was not related to pregnancies and history of lactation, but correlated positively with age at menopause and with time of reproductive period. Low-energy fractures were reported by 286 women, which consists 29.3% of the study group. There was no difference in fracture prevalence between women who delivered (29.4%) or not (27.7%). Also the breastfeeding status was not related to fracture prevalence (28.9% in the subgroup declaring lactation and 31.8% in the others). Women with fractures had earlier age of menopause and shorter time of reproductive period in comparison to subjects without fractures (48.3 ± 5.2 vs. 49.5 ± 4.7 ys.; p < 0.001; OR 0.95 (95% CI: 0.93 - 0.98), and 34.1 ± 5.5 vs. 35.5 ± 4.9 ys.; p < 0.001; OR 0.95 (95% CI: 0.93 - 0.98), respectively). Additionally, fracture prevalence in the 'early menopause' (below 45 ys) subgroup was significantly higher (39.1%) than in all the others (27.8%) with OR 1.66 (95% CI: 1.13 - 2.42).

CONCLUSIONS

Our study did not show a significant association between history of pregnancies or lactation and the skeletal status in the postmenopausal period. However, a shortened period between menarche and menopause and an earlier age at menopause may have a negative impact on bone health in later life. Presented results complement the knowledge on a wide and diverse spectrum of factors modifying bone health in postmenopausal women.