No one knows for sure how long they will live. A new study, however, suggests that leukocyte telomere length may offer some key insights into a woman's longevity and further demonstrates how maternal age at birth of last child affects telomere length and long-term health. Study results are published online today in Menopause, the journal of The North American Menopause Society (NAMS).
This is not the first time that the length of a woman's leukocyte telomeres has been linked with her projected lifespan. Telomeres are repeating DNA-protein complexes that protect the ends of chromosomes and have proven to be critical for maintaining genomic stability. Previous studies have suggested a link between telomere length and various chronic conditions such as cardiovascular disease, type 2 diabetes, some neurologic conditions, and various cancers.
A smaller study previously suggested that maternal age at the birth of a woman's last child affected telomere length. This new, larger-scale study included more than 1,200 perimenopausal and postmenopausal women of various ethnicities and backgrounds from the National Health and Nutrition Examination Survey. In addition, unlike previous studies, this study took into consideration sociodemographic factors related to childbearing patterns and health decisions.
The study confirmed that maternal age at last birth is positively associated with telomere length, meaning that women who delivered their last child later in life were likely to have longer telomeres, a biomarker of long-term health and longevity. This finding was restricted to women with one or two live births or who had used oral contraceptives.
The primary aim of this study was to evaluate if maternal age at birth of last child is associated with leukocyte telomere length in a nationally representative population of peri- and postmenopausal women.
We conducted a cross-sectional analysis of 1,232 women from the National Health and Nutrition Examination Survey to examine maternal age at last birth and telomere length, surveyed between 1999 and 2002. We included peri- and postmenopausal women age 40 years and older. Maternal age at last live birth was self-reported, and leukocyte telomere length was measured using quantitative polymerase chain reaction. We calculated least-squares geometric mean telomere length across categories of maternal age adjusted for age, race/ethnicity, number of live births, survey cycle, and history of hysterectomy or oophorectomy. P-trend < 0.05 was considered statistically significant. For hypothesis-generation, we explored modification by reproductive and sociodemographic factors.
Maternal age at last birth was positively associated with telomere length: the multivariable-adjusted least-squares geometric mean leukocyte telomere length across categories of age at last birth (<25, 25-29, 30-34, 35-39, ≥40 years) was 0.90, 0.93, 0.93, 0.95, and 0.96, respectively (P-trend = 0.04). There was suggestive evidence this association may be restricted to those women with 1 or 2 live births or women who reported ever using oral contraceptives (P-interaction<0.10 for both).
Later maternal age was associated with longer telomere length in a nationally representative population of women. These data provide new insight into the biological relationship between reproductive history and long-term health.
Chase D. Latour, Kelli O’Connell, Megan E. Romano, Elizabeth D. Kantor, Mengmeng Du. Maternal age at last birth and leukocyte telomere length in a nationally representative population of perimenopausal and postmenopausal women. Menopause, 2020; Publish Ahead of Print DOI: 10.1097/GME.0000000000001669