Telomere length: Population epidemiology and concordance in Australian children aged 11-12 years and their parents

ObjectivesTo (1) describe the epidemiology of child and adult telomere length, and (2) investigate parent–child telomere length concordance.DesignPopulation-based cross-sectional study within the Longitudinal Study of Australian Children.SettingAssessment centres in seven major Australian cities and eight selected regional towns; February 2015 to March 2016.ParticipantsOf 1874 participating families, telomere data were available for analysis for 1206 children and 1343 parents, of whom 1143 were parent–child pairs. There were 589 boys and 617 girls; 175 fathers and 1168 mothers.Outcome measuresRelative telomere length (T/S ratio), calculated by comparing telomeric DNA (T) level with the single copy (S) beta-globin gene in venous blood-derived genomic DNA by quantitative real-time PCR.ResultsMean T/S ratio for all children, boys and girls was 1.09 (SD 0.56), 1.05 (SD 0.53) and 1.13 (SD 0.59), respectively. Mean T/S ratio for all parents, fathers and mothers was 0.81 (SD 0.37), 0.82 (SD 0.36) and 0.81 (SD 0.38), respectively. Parent–child T/S ratio concordance was moderate (correlation 0.24). In adjusted regression models, one unit higher parent T/S ratio was associated with 0.36 (estimated linear regression coefficient (β); 95% CI 0.28 to 0.45) higher child T/S ratio. Concordance was higher in the youngest parent-age tertile (β 0.49; 95% CI 0.34 to 0.64) compared with the middle (β 0.35; 95% CI 0.21 to 0.48) and oldest tertile (β 0.26; 95% CI 0.11 to 0.41; p-trend 0.04). Father–child concordance was 0.34 (95% CI 0.18 to 0.48), while mother–child was 0.22 (95% CI 0.17 to 0.28).ConclusionsWe provide telomere length population values for children aged 11–12 years and their mid-life parents. Relative telomere length was shorter in adults than children, as expected. There was modest evidence of parent–child concordance, which diminished with increasing parent age.