Ulcerative colitis (UC) and Crohn's disease have been linked to geographical differences between the northern and southern U.S., according to a new study.
Ulcerative Colitis, Crohn's Cases Show North-South Divide
Posted by Claire Shefchik on November 1, 2011 4:55 PM
"This differential risk may be explained by differences in UV light exposure, vitamin D status, or pollution," hospital researcher Dr. Hamed Khalili told Science Daily.
Investigators from Massachusetts General Hospital examined results from two studies of nurses enrolled in the U.S. Nurses Health Study I and II revealed a north-south divide in U.S. incidences of Crohn's disease and ulcerative colitis.
In a 4,209,454 person-year follow-up, the team confirmed 284 cases of Crohn's disease and 332 cases of ulcerative colitis. They found that where the women lived at age 30 was associated with incidences of the diseases. Women in the southern part of the U.S. had a 50 percent lower chance of Crohn's and a 35 percent lower chance of UC when compared to women in the northern latitudes. Researchers said further studies are needed to examine underlying genetic, lifestyle and environmental factors.
The study was presented at the American College of Gastroenterology's 76th Annual Scientific Meeting, Oct. 28-Nov. 2 in Washington, D.C.