title: Genetic and Environmental Effects on Telomere Length and Lung Function: A Twin Study.
abstract: BACKGROUND
  The purpose of the study was to estimate the heritability of leukocyte telomere length (LTL) and lung function and to examine whether LTL and lung function share genetic or environmental effects in common.
  
  
  METHODS
  386 monozygotic and dizygotic Finnish twin sisters (age 68.4±3.4 years) were included. Relative LTL was determined from peripheral blood DNA by qPCR. Lung function measures of FEV1, FVC, FEV1/FVC, and PEF were derived from spirometry. Genetic modeling was performed with MPlus statistical software.
  
  
  RESULTS
  Univariate analysis revealed that in LTL, 62% (95% confidence interval 50-72) of the variance was explained by additive genetic and 38% (28-50) by unique environmental factors. For FEV1, FVC, and PEF, the corresponding estimates were 65%-67% for additive genetic and 33%-35% for unique environmental factors. Across the sample, the phenotypic correlation between LTL and FEV1 was modest (r = .104, p = .041). Bivariate correlated factors model revealed that the genetic correlation between LTL and FEV1 was .18 (-0.19 to 0.64) and environmental correlation was -.10 (-0.84 to 0.55).
  
  
  CONCLUSIONS
  Both LTL and lung function variables are moderately to highly genetically determined. The associations between LTL and the lung function variables were weak. However, the positive genetic correlation point estimate gave minor suggestions that, in a larger sample, genetic factors in common might play a role in the phenotypic correlation between LTL and FEV1. Future studies with larger samples are needed to confirm these preliminary findings.
authors.affiliation: Gerontology Research Center and Department of Health Sciences, University of Jyväskylä, Finland.
authors.forename: Elina
authors.initials: E
authors.lastname: Sillanpää
authors.affiliation: Gerontology Research Center and Department of Health Sciences, University of Jyväskylä, Finland.
authors.forename: Sarianna
authors.initials: S
authors.lastname: Sipilä
authors.affiliation: Gerontology Research Center and Department of Health Sciences, University of Jyväskylä, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Törmäkangas
authors.affiliation: Department of Public Health and Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Finland.|National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
authors.affiliation: Gerontology Research Center and Department of Health Sciences, University of Jyväskylä, Finland.
authors.forename: Taina
authors.initials: T
authors.lastname: Rantanen
mesh_terms: D000368:Aged; D000375:Aging / Q000235:genetics*; D004781:Environmental Exposure; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D007962:Leukocytes / Q000648:ultrastructure*; D008168:Lung / Q000502:physiology*; D008875:Middle Aged; D013147:Spirometry; D016615:Telomere / Q000235:genetics*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
keywords: Genetic modeling; Spirometry; Telomeres