Kimura T, et al. – The physicians conducted this case–control study to investigate whether specific meteorological factors were associated with the occurrence of ischemic colitis (IC). Possible novel factors correlated with the development of IC were lower air pressure and a decrease in air pressure from the previous day.

• Between January 2003 and June 2010, the physicians retrospectively enrolled 303 patients who had been diagnosed with IC at Suwa Red Cross Hospital in Nagano Prefecture, Japan.
• They compared the meteorological data of the days on which IC patients visited the hospital (IC+ days) with those of the days on which IC patients did not (IC- days).

• Univariate analysis demonstrated that compared with IC- days, IC+ days had significantly lower air pressure (P<0.001), depressed air pressure from the previous day (P<0.001), and fewer daylight hours (P<0.001), as well as higher air temperature (P=0.017), air humidity (P=0.004), wind velocity (P<0.001), and rainfall (P=0.012).
• Multivariate logistic regression analysis of the meteorological data revealed that air pressure (odds ratio: 0.935, P<0.001) and change in air pressure from the previous day (odds ratio: 0.934, P<0.001) were associated with onset of IC.