title: The association between leukocyte telomere length and mitochondrial DNA copy number in pregnant women: a pilot study.
abstract: BACKGROUND
  Both short telomere length and mitochondrial dysfunction have been associated with pregnancy complications, such as preeclampsia and intrauterine growth restriction. However, the relationship between these two biomarkers of oxidative stress, during pregnancy, is unknown. This study investigated the association of leukocyte telomere length with mitochondrial DNA (mtDNA) copy number, an indicator of mitochondrial density and possible mitochondrial dysfunction, using maternal blood samples collected from women with pregnancies uncomplicated by gestational diabetes or hypertensive disorders.
  
  
  METHODS
  Leukocyte telomere length and mtDNA copy number were determined in 75 pregnant women using quantitative real-time quantitative PCR. Bivariate and multivariable linear regression procedures were used to evaluate associations of these two biomarkers.
  
  
  RESULTS
  Leukocyte mtDNA copy number (natural-logarithm) was positively associated with telomere length (Pearson correlation coefficient = 0.30, p-value = 0.009). After adjusting for maternal age and plasma vitamin B12, natural-log mtDNA copy number increased by 0.80 (f = 0.80; 95% CI 0.25 - 1.34, p-value = 0.005) for every 1 unit increase of telomere length. Approximately 11% of the variation in natural-long mtDNA copy number was explained by the model (adjusted R2 = 0.11).
  
  
  CONCLUSIONS
  This cross sectional data suggests an association of mtDNA copy number with telomere length, two emergent biological markers of potential importance in perinatal health research. The consequences of oxidative stress, cellular senescence (as reflected by relatively shorter telomere length) and mitochondrial dysfunction, on the course and outcomes of pregnancy remain to be elucidated in larger prospective studies that include these biological markers.
authors.forename: Chunfang
authors.initials: C
authors.lastname: Qiu
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Enquobahrie
authors.forename: Bizu
authors.initials: B
authors.lastname: Gelaye
authors.forename: Karin
authors.initials: K
authors.lastname: Hevner
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
mesh_terms: D000328:Adult; D015415:Biomarkers; D016922:Cellular Senescence; D003430:Cross-Sectional Studies; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D018628:Gene Dosage; D006801:Humans; D007962:Leukocytes / Q000648:ultrastructure*; D008928:Mitochondria / Q000378:metabolism; D015999:Multivariate Analysis; D018384:Oxidative Stress; D010865:Pilot Projects; D011247:Pregnancy; D012044:Regression Analysis; D016615:Telomere / Q000648:ultrastructure*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004272:DNA, Mitochondrial