Chronobiological analysis of seasonal variations of variceal hemorrhage

Low air temperature increases the risk of oesophageal variceal bleeding: a population and hospital‐based case‐crossover study in Taiwan

“…This study showed that the winter season was associated with the highest risk for EVB in the NHI‐EVB cohort, particularly in February. The winter‐ predominant pattern of EVB in this study was consistent to Turkish , Taiwanese , Japanese , French Tunisia and Chinese studies. In Tahri's study, the seasonal distribution of EVB showed the highest percentage during winter, OR = 3.2 (95% IC = 1.6–6.54) .…”

“…Reduced body temperature resulted in an increase in intrahepatic vascular resistance in an animal study . Increases in blood pressure, cardiac output, peripheral resistance and portal pressure, and reductions in water loss by transpiration and perspiration have also been reported in individuals exposed to LAT . These physical responses may lead to increases in portal pressure, thereby causing EVB.…”

“…Oesophageal variceal bleeding has been found to occur predominantly in the winter season; however, not all patients are believed to be susceptible to this seasonal effect . Moreover, Normura et al .…”

“…Oesophageal variceal bleeding has been found to occur predominantly in the winter season; however, not all patients are believed to be susceptible to this seasonal effect (8)(9)(10)(11)(12)(13). Moreover, Normura et al (15) and L opez-Cepero et al (16) did not identify any monthly or seasonal fluctuations in the incidence of EVB.…”

“…The seasonal variations in EVB have been still controversial (8)(9)(10)(11)(12)(13)(14)(15)(16). It is mostly believed that EVB occurs with seasonal variation, predominantly during the winter (8)(9)(10)(11)(12)(13) or spring season (14). In contrast, only two studies in Spain and Japan concluded there was no seasonal fluctuation of EVB (15,16).…”