title: Associations between rotating night shifts, sleep duration, and telomere length in women.
abstract: BACKGROUND
  Telomere length has been proposed as a marker of aging. However, our knowledge of lifestyle risk factors determining telomere length is limited.
  
  
  METHODS
  We evaluated the associations between years of rotating night shifts, self-reported sleep duration, and telomere length in 4,117 female participants from the Nurses' Health Study. Telomere length in peripheral blood leukocytes was determined by Real-Time PCR assay. Information on rotating night shifts and sleep duration was collected via questionnaires prior to blood collection. We used multivariable linear regression to investigate the associations between rotating night shifts, sleep duration, and telomere length.
  
  
  RESULTS
  Compared with women in the category (9 hours), those in the lowest category of sleep duration (≤6 hours) had a 0.12 unit decrease in z score after adjustment for age, BMI and cigarette smoking (equivalent to 9-year telomere attrition, P for trend  = 0.05). Significant positive association between sleep duration and telomere length was seen among women under age of 50 (P for trend  = 0.004), but not among those over 50 (P for trend  = 0.33) (P for interaction  = 0.005). In addition, we observed that women with a longer history of rotating night shifts tended to have shorter telomere length, but this relation was not statistically significant (P for trend  = 0.36).
  
  
  CONCLUSIONS
  We found that sleep duration was positively associated with telomere length among women under 50 years old. Further research is needed to confirm the observed associations.
authors.affiliation: Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Geyu
authors.initials: G
authors.lastname: Liang
authors.forename: Eva
authors.initials: E
authors.lastname: Schernhammer
authors.forename: Lu
authors.initials: L
authors.lastname: Qi
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Immaculata
authors.initials: I
authors.lastname: De Vivo
authors.forename: Jiali
authors.initials: J
authors.lastname: Han
mesh_terms: D000328:Adult; D000375:Aging / Q000097:blood; D005260:Female; D006801:Humans; D008875:Middle Aged; D012890:Sleep / Q000502:physiology*; D016615:Telomere / Q000378:metabolism*; D059505:Telomere Homeostasis; D014940:Work Schedule Tolerance / Q000502:physiology*