Cognitive Change during the Life Course and Leukocyte Telomere Length in Late Middle-Aged Men

AbstractImportance: Cognitive skills are known to decline through the lifespan with large individual differences. The molecular mechanisms for this decline are incompletely understood. Although leukocyte telomere length provides an index of cellular age that predicts the incidence of age-related diseases, it is unclear whether there is an association between cognitive decline and leukocyte telomere length. Objective: To examine the association between changes in cognitive function during adult life and leukocyte telomere length after adjusting for confounding factors such as education, mental health and life style. Design, setting and participants: Two groups of men with negative (n=97) and positive (n=93) change in cognitive performance were selected from a birth cohort of 1985 Danish men born in 1953. Cognitive performance of each individual was assessed at age ~20 and ~56 years. Leukocyte telomere length at age ~58 was measured using qPCR. Linear regression models were used to investigate the association between cognitive function and leukocyte telomere length. Results: Men with negative change in cognitive performance during adult life had significantly shorter mean leukocyte telomere length than men with positive change in cognitive performance (unadjusted difference β= - 0.09, 95% CI -0.16 - -0.02, p= 0.02). This association remained significant after adjusting for smoking, alcohol consumption, leisure time activity, body mass index and cholesterol (adjusted difference β= -0.09, 95% CI -0.17 - -0.01, p= 0.02) but was nonsignificant after adjusting for smoking, alcohol consumption, leisure time activity, body mass index cholesterol, current cognitive function, depression and education (adjusted difference β= -0.07, 95% CI -0.16 - -0.01, p= 0.08). Conclusion and relevance: Preclinical cognitive changes may be associated with leukocyte telomere length

Effects of repetitive exposure to pain and morphine treatment on the neonatal rat brain

Background: Untreated exposure to pain in preterm neonates might damage the vulnerable premature brain and alter development. Pain treatment is limited because analgesic agents may also have adverse neurodevelopmental consequences in newborns. Objective: To study the effects of neonatal pain and morphine treatment on the developing brain in a n

Smoking does not accelerate leucocyte telomere attrition:A meta-analysis of 18 longitudinal cohorts

Smoking is associated with shorter leucocyte telomere length (LTL), a biomarker of increased morbidity and reduced longevity. This association is widely interpreted as evidence that smoking causes accelerated LTL attrition in adulthood, but the evidence for this is inconsistent. We analysed the association between smoking and LTL dynamics in 18 longitudinal cohorts. The dataset included data from 12 579 adults (4678 current smokers and 7901 non-smokers) over a mean follow-up interval of 8.6 years. Meta-analysis confirmed a cross-sectional difference in LTL between smokers and non-smokers, with mean LTL 84.61 bp shorter in smokers (95% CI: 22.62 to 146.61). However, LTL attrition was only 0.51 bp yr−1 faster in smokers than in non-smokers (95% CI: −2.09 to 1.08), a difference that equates to only 1.32% of the estimated age-related loss of 38.33 bp yr−1. Assuming a linear effect of smoking, 167 years of smoking would be required to generate the observed cross-sectional difference in LTL. Therefore, the difference in LTL between smokers and non-smokers is extremely unlikely to be explained by a linear, causal effect of smoking. Selective adoption, whereby individuals with short telomeres are more likely to start smoking, needs to be considered as a more plausible explanation for the observed pattern of telomere dynamics