title: The effects of social status on biological aging as measured by white-blood-cell telomere length.
abstract: Low socio-economic status (SES) is associated with a shortened life expectancy, but its effect on aging is unknown. The rate of white-blood-cell (WBC) telomere attrition may be a biological indicator of human aging. We tested the hypothesis that SES is associated with telomere attrition independent of known risk factors influencing the aging process. We studied 1552 female twins. A venous blood sample was taken from each twin and isolated WBCs used for extraction of DNA. Terminal restriction fragment length (TRFL) was measured. Questionnaire data were collected on occupation, education, income, smoking, exercise, height and weight. Standard multiple linear regression and multivariate analyses of variance tested for associations between SES and TRFL, adjusting for covariates. A discordant twin analysis was conducted on a subset to verify findings. WBC telomere length was highly variable but significantly shorter in lower SES groups. The mean difference in TRFL between nonmanual and manual SES groups was 163.2 base pairs (bp) of which 22.9 bp (approximately 14%) was accounted for by body mass index, smoking and exercise. Comparison of TRFL in the 17 most discordant SES twin pairs confirmed this difference. Low SES, in addition to the harmful effects of smoking, obesity and lack of exercise, appears to have an impact on telomere length.
authors.affiliation: Twin Research & Genetic Epidemiology Unit, St Thomas' Hospital, London, UK, and The Center of Human Development and Aging, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark 07103-2714, USA.
authors.forename: L F
authors.initials: LF
authors.lastname: Cherkas
authors.forename: A
authors.initials: A
authors.lastname: Aviv
authors.forename: A M
authors.initials: AM
authors.lastname: Valdes
authors.forename: J L
authors.initials: JL
authors.lastname: Hunkin
authors.forename: J P
authors.initials: JP
authors.lastname: Gardner
authors.forename: G L
authors.initials: GL
authors.lastname: Surdulescu
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: T D
authors.initials: TD
authors.lastname: Spector
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007962:Leukocytes; D016014:Linear Models; D008875:Middle Aged; D015999:Multivariate Analysis; D012150:Polymorphism, Restriction Fragment Length; D012042:Registries; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D016615:Telomere; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D044465:White People