ABSTRACT
OBJECTIVES@#Our study examined the dose-response relationship between smoking amounts (pack-years) and the risk of developing pancreatic cancer in Korean men. @*METHODS@#Of 125,743 participants who underwent medical health checkups in 2009, 121,408 were included in the final analysis and observed for the development of pancreatic cancer. We evaluated the associations between smoking amounts and incident pancreatic cancer in 4 groups classified by pack-year amounts. Cox proportional hazards models were used to estimate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of incident pancreatic cancer by comparing groups 2 (40 pack-year smokers) with group 1 (never smokers). @*RESULTS@#During 527,974.5 person-years of follow-up, 245 incident cases of pancreatic cancer developed between 2009 and 2013. The multivariate-adjusted HRs (95% CIs) for incident pancreatic cancer in groups 2, 3, and 4 were 1.05 (0.76 to 1.45), 1.28 (0.91 to 1.80), and 1.57 (1.00 to 2.46), respectively (p for trend=0.025). The HR (95% CI) of former smokers showed a dose-response relationship in the unadjusted model, but did not show a statistically significant association in the multivariate-adjusted model. The HR (95% CI) of current smokers showed a dose-response relationship in both the unadjusted (p for trend=0.020) and multivariate-adjusted models (p for trend=0.050). @*CONCLUSIONS@#The risk of developing pancreatic cancer was higher in current smokers status than in former smokers among Korean men, indicating that smoking cessation may have a protective effect.
ABSTRACT
PURPOSE: Stress during pregnancy is a risk factor for the development of anxiety-related disorders in offspring later in life. The effects of treadmill exercise on anxiety-like behaviors and hippocampal cell proliferation were investigated using rats exposed to prenatal stress. METHODS: Exposure of pregnant rats to a hunting dog in an enclosed room was used to induce stress. Anxiety-like behaviors of offspring were evaluated using the elevated plus maze test. Immunohistochemistry for the detection of 5-bromo-2'-deoxyuridine and doublecortin (DCX) in the hippocampal dentate gyrus and 5-hydroxytryptamine 1A receptors (5-HT(1A)) in the dorsal raphe was conducted. Brain-derived neurotrophic factor (BDNF) and tyrosine kinase B (TrkB) levels in the hippocampus were evaluated by western blot analysis. RESULTS: Offspring of maternal rats exposed to stress during pregnancy showed anxiety-like behaviors. Offspring also showed reduced expression of BDNF, TrkB, and DCX in the dentate gyrus, decreased cell proliferation in the hippocampus, and reduced 5-HT(1A) expression in the dorsal raphe. Postnatal treadmill exercise by offspring, but not maternal exercise during pregnancy, enhanced cell proliferation and expression of these proteins. CONCLUSIONS: Postnatal treadmill exercise ameliorated anxiety-like behaviors in offspring of stressed pregnant rats, and the alleviating effect of exercise on these behaviors is hypothesized to result from enhancement of cell proliferation through 5-HT(1A) activation in offspring rats.