Shared environmental factors associated with telomere length maintenance in elderly male twins

Abstract

SummaryDuring aging, chromosome ends, or telomeres, gradually erode or shorten with each somatic cell division. Loss of telomere length homeostasis has been linked to age-related disease. Remarkably, specific environmental assaults, both physical and psychological, have been shown to correlate with shortened telomeres. However, the extent that genetic and/or environmental factors may influence telomere length during later stages of lifespan is not known. Telomere length was measured in 686 male US World War II and Korean War veteran monozygotic (MZ) and dizygotic (DZ) twins (including 181 MZ and 125 DZ complete pairs) with a mean age of 77.5 years (range 73-85 years). During the entire process of telomere length measurement, participant age and twin status were completely blinded. White blood cell mean telomere length shortened in this elderly population by 71 base pairs per year ( P < < < < 0.0001). We observed no evidence of heritable effects in this elderly population on telomere length maintenance, but rather find that telomere length was largely associated with shared environmental factors ( P < < < < 0.0001). Additionally, we found that individuals with hypertension and cardiovascular disease had significantly shorter telomeres ( P = = = = 0.0025 and 0.002, respectively). Our results emphasize that shared environmental factors can have a primary impact on telomere length maintenance in elderly humans.

Association Between Telomere Shortening and Ageing During Occupational Exposure

“…It indicated that the occupational exposure reduced the length of the telomere in the workers. This finding is probably due to the influence of exposure on genes involved in the telomere length maintenance (32). Correlation of age and telomere length in our study suggested a possible influence of the widespread environmental and occupational ha zards ex posure on ageing acceleration (33)(34)(35), through shortening the telomere length.…”

Organismal stress, telomeres and life histories

“…Findings from the human studies are inconsistent and estimates of heritability vary widely, partly as a consequence of variable sample sizes, differences in the ages at which parent and child telomere length are measured, and the difficulty in accounting for maternal effects and shared environments in the analyses (Gilley et al, 2008). The most reliable data produce heritability estimates in the region of 45%, which clearly indicates a considerable non-genetic component to the inheritance pattern (Baird et al, 2006;Huda et al, 2007;Baird, 2008b;Fraga, 2009). While significant maternal-and paternal-child telomere length correlations have been reported in humans, some (but not all) studies also found an effect of parent age on offspring telomere length; there is also some evidence in humans of a stronger correlation between father and child than between mother and child (Nordfjäll et al, 2010).…”

Short Telomere Length, Myocardial Infarction, Ischemic Heart Disease, and Early Death

“…This is similar to the finding in previous reports of 14 to 29 base pairs lost per year, 3,20,23 but less than that in other reports of up to 7 base pairs lost per year. [22][23][24]26,28 These study differences may reflect interpopulation variation, 29 or they may be a result of interassay variation because some former assays included subtelomeric regions. 30 For myocardial infarction, the present observation of association between decreasing telomere length and increased risk is in accordance with previous studies, 4,20,27,31 all smaller than the present one.…”