Relationship Between Mean Leucocyte Telomere Length and Measures of Allostatic Load in US Reproductive-Aged Women, NHANES 1999-2002.

ABSTRACT

BACKGROUND: Reproductive health disparities may be partly explained by the cumulative effects of chronic stress experienced by socially disadvantaged groups. Although, telomere length (TL) and allostatic load score have each been used as biological markers of stress, the relationship between these two measures is unknown. METHODS: We investigated the association between leucocyte TL and allostatic load score in 1503 non-pregnant women (20-44 years) participating in the National Health and Nutrition Examination Survey, 1999-2002. We constructed six different allostatic load scores using either quartile- or clinical-based cut-points for 14 biomarkers based on previously published methods. We estimated associations between TL and allostatic load scores and component biomarkers using linear regression, also assessing interactions by race/ethnicity. RESULTS: After adjustment for age, longer TL was associated with higher HDL cholesterol and lower C-reactive protein and creatinine clearance; TL was not associated with the other component biomarkers. Shorter TL was associated with higher allostatic load scores for the two clinical cut-point-based scores after adjustment for age, but not the four scores based on quartile cut-points. Significant interactions by race/ethnicity were observed for TL and HbA1c and triglycerides, but not for other component biomarkers or allostatic load scores. CONCLUSIONS: Although TL and allostatic load score are both considered measures of cumulative stress, most component biomarkers and scores using quartile-based cut-points were not associated with TL. In reproductive-aged women, allostatic load scores using clinical-based cut-points were more strongly associated with TL compared with quartile-based scores.