Aging and DNA damage in humans: a meta‐analysis study.

Age‐related DNA damage is regarded as one of the possible explanations of aging. Although a generalized idea about the accumulation of DNA damage with age exists, results found in the literature are inconsistent. To better understand the question of age‐related DNA damage in humans and to identify possible moderator variables, a metaanalysis was conducted. Electronic databases and bibliographies for studies published since 2004 were searched. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for age‐related DNA damage were calculated in a random‐effects model. A total of 76 correlations from 36 studies with 4676 participants were included. Based on our analysis, a correlation between age and DNA damage was found (r=0.230, p=0.000; 95% confidence interval=0.111‐0.342). The test for heterogeneity of variance indicates that the study´s results are significantly high (Q (75)=1754.831, p=0.000). Moderator variables such as smoking habits, technique used, and the tissue/sample analyzed, are shown to influence age‐related DNA damage (p=0.026; p=0.000; p=0.000, respectively). Nevertheless, sex did not show any influence on this relation (p=0.114). In conclusion, this meta‐analysis showed an association between age and DNA damage in humans. It was also found that smoking habits, the technique used, and tissue/sample analyzed, are important moderator variables in age‐related DNA damage.