Combined Effect of Telomere Length and Mitochondrial DNA Copy Number As a Potential Biomarker Indicating PE Risk: a Case-Control Study in a Chinese Population
Abstract Purpose To explore changes of Telomere length (TL) and mitochondrial copy number (mtDNA-CN) in preeclampsia (PE) and to evaluatethe combined effect of maternal TL and mtDNA-CN on PE risk.Methods A case-control study of 471 subjects (130 PE cases and 341 age frequency matched controls) was conducted in Nanjing Drum Tower Hospital, Jiangsu Province of China. Relative telomere length (RTL) and mtDNA-CN were measured using quantitative polymerase chain reaction (qPCR) and PE risk was calculated between groups by logistic regression analyses.Results PE patients displayed longer RTL (0.48 versus 0.30) and higher mtDNA-CN (3.02 versus 2.00) in maternal bloodas well as longer cord blood RTL(0.61 versus 0.35) but lower mtDNA-CN (1.69 versus 5.49) in cord blood (all p<0.001). Exercise during pregnancy exerted an obvious effect of prolonging maternal telomere length. Multiparous, women with folic acid intake during early pregnancy and those delivered vaginally showed longer telomere length while those factors imposed no or opposite effect on RTL in PE cases. Furthermore, RTL and mtDNA-CN were positively correlated in controls (in maternal blood r=0.18, p<0.01; in cord blood r=0.19, p<0.001), but this correlation was disrupted in PE cases, no matter in maternal blood or in cord blood. Longer maternal RTL and higher mtDNA-CN were associated with higher risk of PE, and the ROC curve of RTL and mtDNA-CN in predicting PE risk presented an AUC of 0.755(95%CI: 0.698-0.812).Conclusions Interaction of TL and mtDNA-CN may play an important role in pathogenesis of PE and it could be a potential biomarker indicating PE risk.