DNA damage measured by the comet assay is a well-established biomarker in studies on environmental and occupational exposures, dietary factors and clinical outcomes. Age and sex are typically regarded as confounding factors that are controlled by either selective inclusion criteria of subjects or adjustment in the statistical analysis. This review assesses the influence of age and sex on levels of DNA damage in leukocytes in study populations of healthy subjects. Analysis of unadjusted results in the studies indicates that the level of DNA strand breaks increases by 1% per year (95% CI: 0.9%-1.1%, linear regression analysis weighted for the number of subjects in the individual studies). The studies also show a slightly higher level of DNA strand breaks in men than women (8%, 95% CI: 0.4%-17%) in unadjusted analyses, which is not robust in studies with adjusted analyses. The attenuation of effect in adjusted analyses of DNA strand breaks in leukocytes indicates that the effect of age and sex may be driven by differences in lifestyle factors or other exposures. There do not appear to be differences related to age and sex on basal levels of oxidatively damaged DNA in leukocytes. In summary, the results indicate influences of both age and sex on DNA damage in the comet assay, which may be mediated by lifestyle factors or external exposures rather than direct effects of age and sex.

中文翻译：

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年龄和性别对人血细胞DNA链断裂和DNA氧化损伤水平的影响。

在有关环境和职业暴露，饮食因素和临床结果的研究中，通过彗星测定法测量的DNA损伤是公认的生物标志物。年龄和性别通常被视为混杂因素，受受试者的选择性纳入标准或统计分析调整的控制。该评价评估了年龄和性别对健康受试者研究人群中白细胞DNA损伤水平的影响。对研究中未经调整的结果进行的分析表明，DNA链断裂的水平每年增加1％（95％CI：0.9％-1.1％，根据各个研究中受试者的数量加权进行线性回归分析）。研究还显示，在未经调整的分析中，男性的DNA链断裂水平略高于女性（8％，95％CI：0.4％-17％），这在经过调整分析的研究中并不可靠。调整后的白细胞DNA链断裂分析的效果减弱表明，年龄和性别的影响可能由生活方式因素或其他暴露因素的差异所驱动。白细胞中被氧化损伤的DNA的基础水平似乎与年龄和性别无关。总而言之，结果表明，年龄和性别对彗星试验中DNA损伤的影响均可能由生活方式因素或外部暴露而不是年龄和性别的直接影响介导。白细胞中被氧化损伤的DNA的基础水平似乎与年龄和性别无关。总而言之，结果表明，年龄和性别对彗星试验中DNA损伤的影响均可能由生活方式因素或外部暴露而不是年龄和性别的直接影响介导。白细胞中被氧化损伤的DNA的基础水平似乎与年龄和性别无关。总而言之，结果表明，年龄和性别对彗星试验中DNA损伤的影响均可能由生活方式因素或外部暴露而不是年龄和性别的直接影响介导。