The influence of age and aerobic fitness on chromosomal damage in Austrian institutionalised elderly

Ageing goes hand in hand with altered DNA repair and defence mechanisms against DNA damage. To improve the body's overall resistance against chromosomal damage, maintaining a healthy and active lifestyle is of great concern, especially in the elderly. As more and more people are getting older, they change from home living to an institutionalised situation, which is often accompanied by malnutrition, depression and inactivity. So far, there is a lack of data on chromosomal damage in relation to age and fitness status. The aim of this study was to examine the effect of age and aerobic fitness on endpoints of DNA damage in 105 institutionalised women and men (65-98 years) living in Vienna. Chromosomal damage was measured by conducting the cytokinesis block micronucleus cytome assay. Aerobic fitness of the participants was assessed using the 6-min walking test. To investigate the effect of age on micronuclei (MN) frequency and evaluate the particular age group, our data were merged with data from a recent study by Wallner et al. (Effects of unconjugated bilirubin on chromosomal damage in individuals with Gilbert's syndrome measured with the micronucleus cytome assay. Mutagenesis 2012; 27: 731-735). Age and MN frequency correlated significantly for squared regression (r = 0.577; P = 0.000) and showed a levelling-off at ~60 years of age. Furthermore, we observed a significant negative linear correlation (r = -0.222; P = 0.03) between MN frequency and 6-min walking performance. There was a plateau-like effect of the MN frequency above the age of 60-70 years, indicating a higher resistance against chromosomal damage of the 'survivors' of the regular lifespan. This study suggests that aerobic fitness 'protects' against chromosomal damage at high age.