Health practices and leukocyte DNA damage in Japanese hard-metal workers

Objectives. To investigate associations between total lifestyles and levels of leukocyte DNA damage in healthy Japanese workers. Methods. Eight health practices were investigated in 118 Japanese hard-metal workers by questionnaire in Osaka, Japan, in July 2004. Peripheral leukocyte DNA damage levels, as expressed by comet parameters, were determined using an alkaline comet assay. Results. After crediting one point to each of the health practices and accumulating them into a health practice index (HPI: 0−8 points), subjects with poor health practices (HPI = 0–3 points) showed a significantly higher tail moment than those with moderate (HPI = 4, 5 points) or good health practices (HPI = 6–8 points) (P < 0.01). Risk estimates for tail moment above the 75th percentile showed that, compared to those with good health practices, subjects with moderate health practices had an odds ratio of 1.76 (95% CI: 0.52, 5.91), and those with poor health practices had an odds ratio of 6.75 (95% CI: 1.80, 25.27) (Ptrend < 0.01). Multiple regression analysis showed that HPI was a significant predictor of the decreased tail moment (P < 0.01). Conclusion. Poor lifestyles demonstrate a cumulative association with leukocyte DNA damage in these Japanese hard-metal workers.