Impact of extended working periods on genomic and telomeric DNA and on inflammatory markers: Results of an intervention study with office workers and carpenters.

ABSTRACT

Aim of this study was to clarify if extension of the work phase has an impact on DNA- stability, telomere lengths and inflammatory markers. We conducted an intervention trial with office workers (n = 24) and carpenters (n = 10), who changed their working schedule from 8 to 12 h per day over a period of 3 months. The work of both groups involved only moderate physical activity. We found no evidence for induction of double strand breaks (measured in γH2AX assays) and relative telomere lengths (relTL_36B4 and ALB) in lymphocytes in the two study groups. Furthermore, no overall changes of the levels of C-reactive protein (CRP), interleukin-6 (IL-6) and thiobarbituric acid reactive substances (TBARS) in plasma were detected. However, we found in agreement with earlier investigations a moderate (not significant) increase of the CRP levels with age. Furthermore, significant higher CRP concentrations (P = 0.03) were detected in young individuals (21-30 years) as a consequence of the extended working period. Taken together our findings indicate that prolongation of the working hours has no pronounced impact on DNA stability, telomere shortening and inflammatory markers; but the increase of the CRP concentrations in young workers may be indicative for adverse health effects in this subgroup.