Influence of climatic factors in the incidence of upper gastrointestinal bleeding

BACKGROUND AND AIM: Previous reports have indicated seasonal fluctuations in the incidence of peptic ulcer activity, but the reasons for the seasonal pattern are not clear. We assessed the seasonal incidence of hematemesis caused by peptic ulcers or gastroesophageal varices, and the correlations between those and climatic factors. METHODS: We examined the number of cases of upper gastrointestinal (GI) bleeding caused by gastric ulcer (GU), duodenal ulcer (DU), or gastroesophageal varices (varix) diagnosed by urgent endoscopies between 1 January 1996 and 31 December 1999 in our hospital (Tokyo Metropolitan Bokutou Hospital). We evaluated the monthly and seasonal incidence of them and investigated correlations among the incidence and climatic factors. RESULTS: Four hundred and forty-one patients participated in this study, including 275 patients with GU (62.4%), 51 (11.6%) with DU, and 115 (26.0%) with varix. The number of cases of hematemesis caused by GU showed significant monthly and seasonal fluctuations (P = 0.0002, P = 0.0018): it decreased in summer and increased in autumn-winter. Moreover, there were inverse relations between the monthly number of cases of hematemesis caused by GU and the mean temperature (P = 0.0016) and vapor pressure (P = 0.0013), and a parallel relation to the mean atmospheric pressure (P = 0.0057). In contrast, the number of cases of hematemesis caused by DU and varices did not show any monthly or seasonal fluctuations. CONCLUSIONS: We found that the incidence of hematemesis because of GU had an inverse relationship to temperature and vapor pressure, and had a parallel relation to atmospheric pressure. Therefore, climatic factors may play an important role in hemorrhage from GU.