Influence of chronic moderate sleep restriction and exercise on inflammation and carcinogenesis in mice

The effects of chronic moderate sleep restriction and exercise training on carcinogenesis were examined in adenomatous polyposis coli multiple intestinal neoplasma (APC Min(+/-)) mice, a genetic strain which is predisposed to developing adenomatous polyposis. The mice were randomized to one of four 11 week treatments in a 2×2 design involving sleep restriction (by 4 h/day) vs. normal sleep and exercise training (1h/day) vs. sedentary control. Wild-type control mice underwent identical experimental treatments. Compared with the wild-type mice, APC Min(+/-) mice had disrupted hematology and enhanced pro-inflammatory cytokine production from peritoneal exudate cells. Among the APC Min(+/-) mice, consistent interactions of sleep loss and exercise were found for measures of polyp formation, inflammation, and hematology. Sleep loss had little effect on these variables under sedentary conditions, but sleep loss had clear detrimental effects under exercise conditions. Exercise training resulted in improvements in these measures under normal sleep conditions, but exercise tended to elicit no effect or to exacerbate the effects of sleep restriction. Significant correlations of inflammation with polyp burden were observed. Among wild-type mice, similar, but less consistent interactions of sleep restriction and exercise were found. These data suggest that the benefits of exercise on carcinogenesis and immune function were impaired by chronic moderate sleep restriction, and that harmful effects of sleep restriction were generally realized only in the presence of exercise.