Review of Inflammatory Bowel Disease in China

Table 3

Ages and gender distribution of UC and CD.

Region	UC			CD
	Peak age of onset (years)	Mean age of onset (years)	Ratio (male/female)	Peak age of onset (years)	Mean age of onset (years)	Ratio (male/female)
Mainland China [3, 4]	40–49	44.1	1.34 : 1	31–40	37.7	1.67 : 1
Hong Kong [6]	30–39	40.6	1.34 : 1
Hong Kong [7]	25–34*; 45–54**	40.4; 37^◆	1.07 : 1
China [25]					37.2 Mainland; 32.1 Hong Kong	2.5 : 1
Japan [10]	30–35		1.15 : 1	30–35		2.3 : 1
Korea [12]		35^◆	0.99 : 1		21.5^◆	2.83 : 1
Western countries [22]	30–40			20–30

∗The first peak age of onset, **the second peak age of onset, and ^◆median age.