In the northern hemisphere, the incidence of inflammatory bowel diseases (IBD) has a north–south gradient, suggesting a link between ultraviolet (UV) exposure or vitamin D status and the pathogenesis of IBD.
Dr Limketkai and colleagues from Maryland, USA tested the association of UV exposure with the rates and severity of IBD hospitalization.
The researchers conducted a retrospective nationwide analysis of 649,932 Crohn's disease (CD), 384,267 ulcerative colitis (UC), and 288,894,297 non-IBD hospitalizations in the US between 1998 and 2010.
Mean UV exposure was assigned to each hospitalization using surface measures from the National Oceanic and Atmospheric Administration.
|Low UV was associated with prolonged hospitalizations,|
|Alimentary Pharmacology & Therapeutics|
The team noted that relative rates across UV exposures were estimated for IBD hospitalizations, prolonged hospitalizations, bowel surgeries and deaths.
Among IBD patients, lower UV exposures had increased hospitalization rates for CD and UC.
The research team found that low UV groups had greater relative rates of prolonged hospitalizations, bowel surgeries, and CD deaths.
The researchers observed that among non-IBD patients, low UV was associated with prolonged hospitalizations, and deaths, but not bowel surgeries.
Dr Limketkai's team comments, "Lower ultraviolet exposure is associated with greater rates of hospitalization, prolonged hospitalization and the need for bowel surgery in IBD."
"This trend for bowel surgery was not seen with non-IBD encounters."