Abstract 1782: Racial differences in maternal and cord blood leukocyte telomere length and their correlations
Authors: Weber Kari A. , Heaphy Christopher M. , Joshu Corinne E. , Rohrmann Sabine , Bienstock Jessica L. , Agurs-Collins Tanya , Meeker Alan K. , Platz Elizabeth A. 
Published: July 2016

Background: Telomere length at birth is hypothesized to set the baseline for lifetime telomere shortening trajectory and influence adult disease risk including prostate cancer, which shows a pronounced racial disparity. Telomere length is heritable, but may also be a marker of exposures in utero, including those impacting adult cancer risk. Thus, we investigated racial differences in leukocyte telomere length in maternal blood and cord blood from their male neonates, and in telomere length correlations between mothers and neonates. The purpose of this work is to inform whether telomere length differences at birth may account for some of the racial disparity in adult disease risk.

Methods: Black and white Baltimore women were recruited at the start of pregnancy in 2006-7 and followed to postpartum. They completed surveys at enrollment and at the first postpartum visit. Medical records were abstracted from each clinic visit, mothers provided blood each trimester, and cord blood was collected at birth. 55 mother-male neonate pairs with complete materials were included. Relative telomere length (telomere/single copy gene) was measured by quantitative PCR in leukocyte DNA. We used linear regression to estimate mean telomere length in mothers and neonates before and after adjusting for assay batch, mother's age and other factors. We calculated the Pearson correlation between mother and cord blood telomere length overall and by race.

Results: Black mothers were younger, less likely to have a graduate degree and to be nulliparous, and more likely to be overweight/obese than white mothers. Adjusting for batch and mother's age, black mothers had shorter mean telomere length (2.18, 95% CI 1.81-2.56) than white mothers (2.65, 95% CI 2.35-2.95) and black neonates had shorter mean telomere length (2.64, 95% CI 2.27-3.01) than white neonates (3.02, 95% CI 2.73-3.31); differences were not significant (p = 0.08, 0.1). Differences were attenuated after further adjustment for education, nulliparity, and BMI. Adjusting for mother's age, mother and cord blood telomere lengths were highly correlated overall (r = 0.73, p&lt;0.0001), and did not differ between blacks (r = 0.77) and whites (r = 0.67; p-interaction = 0.6). Correlations were similar after further adjustment for education, nulliparity, and BMI.

Conclusion: Leukocyte telomere length was shorter in black compared with white mothers and in cord blood, but racial differences were attenuated after adjustment. Correlation between mother and neonate telomere length was high, did not differ by race, and was not attenuated after adjustment. Our results appear to support the hypothesis that telomere length differs by race at birth in part due to inherent differences and in part due to maternal factors, and thus, may inform the racial disparity in risk of adult diseases like prostate cancer.

Funding: T32 CA009314, U54 CA091409, P30 CA006973, Dept of Epidemiology Doctoral Research Fund

Citation Format: Kari A. Weber, Christopher M. Heaphy, Corinne E. Joshu, Sabine Rohrmann, Jessica L. Bienstock, Tanya Agurs-Collins, Alan K. Meeker, Elizabeth A. Platz. Racial differences in maternal and cord blood leukocyte telomere length and their correlations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1782.