Association between maternal urinary manganese concentrations and newborn telomere length: Results from a birth cohort study

Objective: Telomere length (TL) is a biomarker for biological aging, and the initial setting of TL at birth is a determinant factor of TL in later life. Newborn TL is sensitive to maternal metals concentrations, while study about the association between maternal manganese (Mn) concentrations and newborn TL was not found. Our study aimed to investigate whether newborn TL is related to maternal Mn concentrations. Methods: Data were collected from a birth cohort study of 762 mother-newborn pairs conducted from November 2013 to March 2015 in Wuhan, China. We measured the Mn concentrations in spot urine samples collected during three trimesters by inductively coupled plasma mass spectrometry (ICP-MS) and relative cord blood TL by quantitative real-time polymerase chain reaction (qPCR). We applied multiple informant models to investigate the associations between maternal Mn concentrations and cord blood TL. Results: The geometric mean of creatinine-corrected urinary Mn concentrations were 1.58 mu g/g creatinine, 2.53 mu g/g creatinine, and 2.62 mu g/g creatinine in the first, second, and third trimester, respectively. After adjusting for potential confounders, a doubling of maternal urinary Mn concentration during the second trimester was related to a 2.10% (95% CI: 0.25%, 3.99%) increase in cord blood TL. Mothers with the highest tertile of urinary Mn concentrations during the second trimester had a 9.67% (95% CI: 2.13%, 17.78%) longer cord blood TL than those with the lowest tertile. This association was more evident in male infants. No relationship was found between maternal urinary Mn concentrations and cord blood TL during the first and third trimesters in our study. Conclusions: Our findings suggested that maternal Mn concentration during the second trimester was positively associated with newborn TL. These results might provide an epidemiology evidence on the protective role of maternal Mn for newborn TL and offer clues for the early prevention of telomere shortening related diseases.