title: Race, Ethnicity, Psychosocial Factors, and Telomere Length in a Multicenter Setting.
abstract: BACKGROUND
  Leukocyte telomere length(LTL) has been associated with age, self-reported race/ethnicity, gender, education, and psychosocial factors, including perceived stress, and depression. However, inconsistencies in associations of LTL with disease and other phenotypes exist across studies. Population characteristics, including race/ethnicity, laboratory methods, and statistical approaches in LTL have not been comprehensively studied and could explain inconsistent LTL associations.
  
  
  METHODS
  LTL was measured using Southern Blot in 1510 participants from a multi-ethnic, multi-center study combining data from 3 centers with different population characteristics and laboratory processing methods. Main associations between LTL and psychosocial factors and LTL and race/ethnicity were evaluated and then compared across generalized estimating equations(GEE) and linear regression models. Statistical models were adjusted for factors typically associated with LTL(age, gender, cancer status) and also accounted for factors related to center differences, including laboratory methods(i.e., DNA extraction). Associations between LTL and psychosocial factors were also evaluated within race/ethnicity subgroups (Non-hispanic Whites, African Americans, and Hispanics).
  
  
  RESULTS
  Beyond adjustment for age, gender, and cancer status, additional adjustments for DNA extraction and clustering by center were needed given their effects on LTL measurements. In adjusted GEE models, longer LTL was associated with African American race (Beta(β)(standard error(SE)) = 0.09(0.04), p-value = 0.04) and Hispanic ethnicity (β(SE) = 0.06(0.01), p-value = 0.02) compared to Non-Hispanic Whites. Longer LTL was also associated with less than a high school education compared to having greater than a high school education (β(SE) = 0.06(0.02), p-value = 0.04). LTL was inversely related to perceived stress (β(SE) = -0.02(0.003), p<0.001). In subgroup analyses, there was a negative association with LTL in African Americans with a high school education versus those with greater than a high school education(β(SE) = -0.11(0.03), p-value<0.001).
  
  
  CONCLUSIONS
  Laboratory methods and population characteristics that differ by center can influence telomere length associations in multicenter settings, but these effects could be addressed through statistical adjustments. Proper evaluation of potential sources of bias can allow for combined multicenter analyses and may resolve some inconsistencies in reporting of LTL associations. Further, biologic effects on LTL may differ under certain psychosocial and racial/ethnic circumstances and could impact future health disparity studies.
authors.affiliation: University of Pennsylvania, Philadelphia, PA, United States of America.|Fox Chase Cancer Center, Philadelphia, PA, United States of America.
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Lynch
authors.affiliation: University of Texas Medical Branch, Galveston, TX, United States of America.
authors.forename: M K
authors.initials: MK
authors.lastname: Peek
authors.affiliation: University of Pennsylvania, Philadelphia, PA, United States of America.
authors.forename: Nandita
authors.initials: N
authors.lastname: Mitra
authors.affiliation: Wistar Institute, Philadelphia, PA, United States of America.
authors.forename: Krithika
authors.initials: K
authors.lastname: Ravichandran
authors.affiliation: University of Pennsylvania, Philadelphia, PA, United States of America.
authors.forename: Charles
authors.initials: C
authors.lastname: Branas
authors.affiliation: University of Pennsylvania, Philadelphia, PA, United States of America.
authors.forename: Elaine
authors.initials: E
authors.lastname: Spangler
authors.affiliation: University of Pennsylvania, Philadelphia, PA, United States of America.
authors.forename: Wenting
authors.initials: W
authors.lastname: Zhou
authors.affiliation: The Ohio State University, Columbus, OH, United States of America.
authors.forename: Electra D
authors.initials: ED
authors.lastname: Paskett
authors.affiliation: Washington University, St. Louis, MO, United States of America.
authors.forename: Sarah
authors.initials: S
authors.lastname: Gehlert
authors.affiliation: The Ohio State University, Columbus, OH, United States of America.
authors.forename: Cecilia
authors.initials: C
authors.lastname: DeGraffinreid
authors.affiliation: University of Pennsylvania, Philadelphia, PA, United States of America.|Dana Farber Cancer Institute and Harvard University, Boston, MA, United States of America.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Rebbeck
authors.affiliation: University of Texas Medical Branch, Galveston, TX, United States of America.|Old Dominion University, Norfolk, VA, United States of America.
authors.forename: Harold
authors.initials: H
authors.lastname: Riethman
mesh_terms: D000328:Adult; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011584:Psychology; D044469:Racial Groups; D012044:Regression Analysis; D012959:Socioeconomic Factors; D059505:Telomere Homeostasis