Levels of DNA damage represent the dynamics between damage formation and removal. Therefore, to better interpret human biomonitoring studies with DNA damage endpoints, an individual's ability to recognize and properly remove DNA damage should be characterized. Relatively few studies have included DNA repair as a biomarker and therefore, assembling and analyzing a pooled database of studies with data on base excision repair (BER) was one of the goals of hCOMET (EU-COST CA15132). A group of approximately 1911 individuals, was gathered from 8 laboratories which run population studies with the comet-based in vitro DNA repair assay. BER incision activity data were normalized and subsequently correlated with various host factors. BER was found to be significantly higher in women. Although it is generally accepted that age is inversely related to DNA repair, no overall effect of age was found, but sex differences were most pronounced in the oldest quartile (>61 years). No effect of smoking or occupational exposures was found. A body mass index (BMI) above 25 kg/m2 was related to higher levels of BER. However, when BMI exceeded 35 kg/m2, repair incision activity was significantly lower. Finally, higher BER incision activity was related to lower levels of DNA damage detected by the comet assay in combination with formamidopyrimidine DNA glycosylase (Fpg), which is in line with the fact that oxidatively damaged DNA is repaired by BER. These data indicate that BER plays a role in modulating the steady-state level of DNA damage that is detected in molecular epidemiological studies and should therefore be considered as a parallel endpoint in future studies.

Cancer Research Institute Biomedical Research Center of the Slovak Academy of Sciences 84505 Bratislava Slovakia

Department of Biology Faculty of Medicine Slovak Medical University 833 03 Bratislava Slovakia

Department of Non ionizing Radiation National Public Health Center H 1221 Budapest Hungary

Department of Nutrition University of Oslo Norway

Department of Pharmacology and Toxicology School for Nutrition and Translational Research in Metabolism Maastricht University the Netherlands

Department of the Molecular Biology of Cancer Institute of Experimental Medicine of the Czech Academy of Sciences Prague 14200 Czech Republic

Department of the Molecular Biology of Cancer Institute of Experimental Medicine of the Czech Academy of Sciences Prague 14200 Czech Republic; Institute of Biology and Medical Genetics 1st Faculty of Medicine Charles University Prague 12800 Czech Republic; Biomedical Centre Faculty of Medicine in Pilsen Charles University Pilsen 306 05 Czech Republic

Gazi University Faculty of Pharmacy Department of Toxicology Etiler Ankara 06330 Turkey

Genetics and Biotechnology Department and Veterinary and Animal Research Centre Universidade de Trás os Montes e Alto Douro Vila Real Portugal

Group of Mutagenesis Department of Genetics and Microbiology Faculty of Biosciences Universitat Autònoma de Barcelona Cerdanyola del Vallès Barcelona Spain

Health Effects Laboratory Department of Environmental Chemistry Norwegian Institute for Air Research 2002 Kjeller Norway

Instituto de Investigación Biomédica de A Coruña Departamento de Biología Facultad de Ciencias Campus A Zapateira s n 15071 A Coruña Spain

Instituto de Investigación Biomédica de A Coruña Departamento de Psicología Facultad de Ciencias de la Educación Campus Elviña s n 15071 A Coruña Spain

Mutagenesis Unit Institute for Medical Research and Occupational Health Zagreb Croatia

Oslo Metropolitan University Faculty of Health Sciences PO Box 4 St Olavs plass 0130 Oslo Norway

Unit of Clinical and Molecular Epidemiology IRCCS San Raffaele Pisana Rome Italy; Department of Human Sciences and Quality of Life Promotion San Raffaele University Rome Italy

References provided by Crossref.org

A pooled analysis of host factors that affect nucleotide excision repair in humans