12 Iran does not have as high a prevalence rate of IBDs as do western countries; however, due to changes in people’s lifestyle and industrialization in tandem with other Asian countries, we may expect a rising trend in our region.13 Indeed,

a proliferation in the number of published articles on IBDs during the last decade is evidence of the vigorous elevation of concerns over IBDs in Iran: where there were only 3 articles on IBDs before the year 2000 in Iran, the period between 2000 and 2012 saw the figure soar to 26 articles. A study in South Korea showed that the prevalence of UC was 7.57 in 100,000 individuals in 1997, whereas an increase of 30.87 patients in 100,000 individuals was noted in 2005.14 Inhibitors,research,lifescience,medical This rising trend is also visible in Japan. The prevalence of CD, which was 2.9 in 100,000 people in Japan in 1986, reached 13.5 in 1998.15 The prevalence of IBDs in the Middle East countries such as Lebanon16 and Israel17 also indicates a growing trend. The prevalence of UC in Kuwait in 1999 Inhibitors,research,lifescience,medical was 41.7 for 100,000 individuals.18 The annual incidence rates of UC and CD were 3.08 and 1.34 cases per 100,000 person-years in South Korea,14 1.95 and 0.51 in Japan,19 4.1

and 1.4 in Lebanon,17 and 5.04 and Inhibitors,research,lifescience,medical 5.0 cases per 100,000 person-years in Kibbutz, Israel17 respectively. A population-based study in Punjab, North India, demonstrated that the prevalence of UC was 44.3 in 100,000 persons and the incidence of this disease was 6.02 per 100,000 person-years.20 Demographic Variables: Gender Gender assessment on IBDs in Iran Inhibitors,research,lifescience,medical illustrates male/female (M/F) ratios for UC of 1.6/1,21 0.78/1.0,12 0.7/1.0,22 0.8/1.0,23 and 1.2/1.1,24 and M/F ratios for CD of 1.4/1.0,21 1.18/1.0,12 0.9/1.0,22 1.2/.8,24 and 1.3/1.0.23 It seems that female predominance in UC and male predominance in CD are the major demographic patterns of IBDs in Iran. The male predominance has been

Inhibitors,research,lifescience,medical AG-014699 in vivo reported for CD in China,25 Japan,15 and Korea.14 The M/F ratio for UC is nearly equal in Korea and Japan26 and the F/M ratio is 1.33 in Riyadh, Saudi Arabia.27 Age The mean age at diagnosis of IBDs in Iranian patients is identical to that of other Asian countries; while in four different studies, it was 33.6 for UC12,23,28 and 32.3 for CD.12,23 One peak age of onset has been reported in the second decade of life and the second peak Bay 11-7085 has not been seen in Iran.12,22,23,29 Based on one report, Asian countries have a peak age of onset at 20-39 years of age for both diseases and the second peak has not been seen in most of them; whereas a small second peak has been reported by the same author in another study.14 The trend of the second peak has also been observed in a study conducted in the Chinese population of Hong Kong.25 Urban Versus Rural Distribution This factor has been assessed in three studies in Iran. The mean percentage of UC in urban areas was reported to be 73.8%, whereas this mean percentage for CD was 86%23,29 which clearly denotes a higher prevalence rate in city dwellers.