Pregnancy during adolescence increases osteoporosis risk after menopause
MedWire News: Women who become pregnant during adolescence may be at an increased risk for osteoporosis after they reach the menopause, researchers say.
Previous research has indicated that pregnancy during adolescence, a critical time of life during which bone is accumulated for peak bone mass, may have detrimental effects on bone mass after pregnancy.
Jung-Ho Shin (Korea University, Seoul) and colleagues conducted a cross-sectional study of 719 postmenopausal women from the Korean National Health and Nutrition Survey in 2008. Their bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry.
Osteoporosis was defined as having a T-score lower than -2.5 at the total hip, femoral neck, or lumbar spine.
Postmenopausal women who had a history of adolescent pregnancy (mean age at first birth 18.40 years; n=93) had significantly lower BMD in the measured sites than those without a history of adolescent pregnancy (mean age at first birth 23.75 years; n=626). Indeed, postmenopausal women with a history of adolescent pregnancy had a total hip BMD of 0.70 g/m2 versus 0.78 g/m2, in those without such a history, a femoral neck BMD of 0.56 g/m2 versus 0.62 g/m2, and a lumbar BMD of 0.75 g/m2 versus 0.80 g/m2.
Furthermore, analysis of BMD data revealed that postmenopausal women who had been pregnant during adolescence had a significantly higher prevalence of osteoporosis than those who were not, at 62.4% versus 35.8%.
Multivariate analysis adjusted for potential confounders including body mass index, marital status, and smoking history showed that postmenopausal women who were pregnant during adolescence had a significant 1.84-fold increased risk for osteoporosis than those without a history of adolescent pregnancy.
The authors suggest that the changes in calcium homeostasis that occur in response to the demands of the fetus during pregnancy may interfere with the formation of peak bone mass, which in turn puts women at greater risk for osteoporosis during later years.
"Further studies are required to clarify the effect of these factors on the association between adolescent pregnancy and osteoporosis during categories of duration," Shin and team conclude in Menopause.
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By Piriya Mahendra