Association between delivery at an advanced maternal age and osteoporosis in elderly Korean women

Abstract

Although several reproductive factors have been associated with low bone mineral density (BMD) in elderly women, few studies have evaluated the long-term effects of delivery at a high-risk maternal age on BMD. Using nationally representative survey data collected from 736 women aged 65 years or older, we evaluated the relationship between delivery during adolescence or at an age of 35 years or older and osteoporosis in elderly women. Data regarding demographic and socioeconomic characteristics, medical history, lifestyle risk factors, reproductive history, and history of osteoporosis and fracture were collected by administration of self-report questionnaires. Anthropometric data and BMD were measured in accordance with standardized guidelines. Independent determinants of BMD were identified by stepwise multiple linear regression analysis, and the resulting model was used to evaluate the risk of osteoporosis according to delivery during adolescence or at an advanced age. Of the 736 subjects, 426 (60.1 %) were found to have osteoporosis (T score ≤ -2.5), and 19.2 and 38.9 % reported delivery during adolescence and at an advanced age, respectively. The incidence of delivery during adolescence or at an advanced age was significantly higher in subjects with osteoporosis than in those without osteoporosis. After adjustment for covariates, multiple logistic regression analysis revealed that elderly women with a history of delivery at an advanced maternal age are at an increased (2.164-fold greater) risk of osteoporosis (95 % confidence interval 1.109-4.223) compared with elderly women without a history of delivery at an advanced age. However, a history of delivery during adolescence did not affect the risk.

Keywords: Bone mineral density; Korea National Health and Nutrition Examination Survey; Maternal age; Osteoporosis; Parity.