People with chronic inflammatory bowel disease have a higher risk of developing cardiovascular disease, such as a heart attack. However, Danish research shows that the increased risk is not explained by traditional risk factors.
Inflammatory bowel disease, such as Crohn’s disease and ulcerative colitis, can affect the rest of the body and can influence the risk of developing cardiovascular disease.
A major population study in Denmark shows that people with inflammatory bowel disease also have an increased risk of developing ischaemic heart disease.
The research has been published in the Journal of Crohn’s & Colitis.
“Our study indicates that people with inflammatory bowel disease have an increased risk of developing cardiovascular disease, but this risk is not linked to the traditional risk factors for cardiovascular disease, such as high blood pressure or high cholesterol. Inflammation seems to be the triggering factor,” explains a researcher behind the study, Kristine Allin, Staff Specialist and Research Leader, Department of Epidemiology Research, Statens Serum Institut and Associate Professor, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen.
Data from more than 100,000 Danes
The researchers obtained data from the prospective Copenhagen General Population Study, in which researchers have examined the health and lifestyles of a large group of Danes since 2003 to discover how lifestyle factors affect health and how developing various diseases affects the risk of developing others.
The study includes 108,789 participants, of which 1,203 have inflammatory bowel disease: 347 Crohn’s disease and 856 ulcerative colitis.
The researchers compared various risk markers for developing cardiovascular disease such as high cholesterol, high blood pressure and high body mass index and how they differed between people with inflammatory bowel disease and the background population.
The researchers also determined how many people in each group developed cardiovascular disease.
Finally, the researchers examined markers of inflammation in each group.
Increased risk of cardiovascular disease but not linked to traditional risk factors
The study showed that 13% of the people with inflammatory bowel disease had developed cardiovascular disease versus 11% for the background population. This corresponds to about 20% more cases of cardiovascular disease among people with inflammatory bowel disease.
Surprisingly, the traditional risk factors for cardiovascular disease – blood pressure, cholesterol and body mass index – were not increased for people with inflammatory bowel disease.
However, the researchers determined the levels of the inflammation marker C-reactive protein with a highly sensitive test and found that people with inflammatory bowel disease had slightly elevated levels: 1.6 versus 1.4 mg/L in the background population.
“We were of course not surprised that people with inflammatory bowel disease have a generally increased level of inflammation,” says Kristine Allin.
Optimally managing inflammatory bowel disease could reduce the risk of cardiovascular disease
Kristine Allin explains that the result is interesting because it suggests that systemic inflammation rather than traditional cardiovascular risk factors is probably the underlying cause of the higher prevalence of cardiovascular disease among people with inflammatory bowel disease.
Inflammation affects the heart and the blood vessels and can result in blood clots in both the heart and the brain.
“This shows that optimally managing bowel inflammation is incredibly important for these people, primarily because of the inflammatory bowel disease itself but also because the systemic inflammation seems to increase their risk of developing cardiovascular disease,” explains Kristine Allin.
Optimally treating people with inflammatory bowel disease
Since people with inflammatory bowel disease generally do not have higher blood pressure or cholesterol levels than the general population, using solely traditional treatments to prevent cardiovascular disease, such as cholesterol-lowering or blood pressure medicine, may not reduce the risk of developing cardiovascular disease.
The study suggests that immunosuppressive drugs could reduce the risk of cardiovascular disease by dampening the inflammatory bowel disease; these include the new anti-tumour necrosis factor drugs that have emerged recently.
“Managing the inflammatory bowel disease is crucial to prevent it from flaring up uncontrollably. Optimizing treatment can probably also reduce the increased risk of developing cardiovascular disease,” concludes Kristine Allin.