Abstract
We have pointed out that the incidence of cerebral and myocardial infarction that occur early in the morning is high and estimated its correlation with blood viscosity as a cause. To clarify the mechanism of onset of such diseases early in the morning in further details, we examined the effect of alcohol drinking and hot spring bathing on the circadian changes in blood viscosity on normotensive and nonsmoking young men. It was observed that both drinking a bottle or 633ml of beer containing 4.5% alcohol and taking a hot spring bath at 42°C for 10 minutes at 8p.m. tended to enhance the rate of increase in blood viscosity between 4a.m. and 8a.m. the next morning as compared with the control. In contrast, drinking 500ml of water at 0a.m. after either drinking a bottle of beer or having a hot spring bath mitigated the change in blood viscosity the next morning. These findings may suggest that both drinking alcohol and taking a hot spring bath around dinner time elevate the rate of increase in blood viscosity in the next morning, leading to possible onset of cerebral and myocardial infarction. Drinking two glasses of water at midnight is effective in preventing such change in blood viscosity in the morning.
