J Korean Med Sci.  2018 Nov;33(48):e311. 10.3346/jkms.2018.33.e311.

Effect of Childbirth Age on Bone Mineral Density in Postmenopausal Women

• We JS
• Han K
• Kwon HS
• Kil K

• KMID: 2426664
• DOI: http://doi.org/10.3346/jkms.2018.33.e311

Abstract

BACKGROUND
In postmenopausal women, there is rapid bone loss due to estrogen depletion. In women, reproductive factors such as age at menarche, breastfeeding, and parity are considered risk factors of osteoporosis. Many reports suggest that obesity is associated with a reduced risk of osteoporosis. This nationwide, population-based study aims to identify the association between maternal age and osteoporosis risk in postmenopausal women of different obesity classifications.
METHODS
We assessed data from the Korean National Health and Nutrition Examination Survey 2010-2012. The study included 1,328 postmenopausal women, after excluding women with missing data for reproductive history among 4,546 postmenopausal women in the survey. Multivariate regression was used to identify the association between childbirth age and postmenopausal bone mineral density after adjustments for confounding factors.
RESULTS
The prevalence of postmenopausal osteoporosis was 35.24% (n = 468). After dividing the subjects into obese and non-obese groups based on body mass index (BMI) and waist circumference, there were significant differences between non-osteoporosis and osteoporosis groups with regard to age at first childbirth, age at last childbirth, and parity in the BMI-based general obesity group. The prevalence of osteoporosis was highest in women older than 35 years old at last childbirth. The prevalence of osteoporosis was also greater in women with parity ≥ 4 compared to those with lower parity levels.
CONCLUSION
Postmenopausal women of older age at last childbirth and higher parity were at increased risk of osteoporosis in the BMI-based non-general obesity group.

Keyword

Maternal Age; Osteoporosis; Bone Mineral Density; Obesity; Parity

MeSH Terms

Body Mass Index
Bone Density*
Breast Feeding
Classification
Estrogens
Female
Humans
Maternal Age
Menarche
Nutrition Surveys
Obesity
Osteoporosis
Osteoporosis, Postmenopausal
Parity
Parturition*
Prevalence
Reproductive History
Risk Factors
Waist Circumference
Estrogens