Predicting the chances of someone developing a disease is not an exact science, but researchers from Pittsburgh say comparing the ratio of harmful factors with protective ones may give a more accurate picture.
In a study to find out how heart disease risks in patients with type 1 diabetes can be better assessed, researchers from the University of Pittsburgh Graduate School of Public Health looked to evidence collected between 1950 and 1980.
Diabetes affects 25.8 million Americans according to figures from a 2011 fact sheet published by the Centers for Disease Control and Prevention (CDC). And figures from 2004 show that adults with diabetes are between two and four times more likely to die from heart disease than those without diabetes.
The CDC fact sheet explains that type 1 diabetes is usually diagnosed in children and young adults. The body’s immune system destroys pancreatic beta cells. These are the only cells in the body that make insulin, the hormone that regulates blood glucose. People with type 1 diabetes must have insulin, delivered by injection or a pump, to survive.
In adults, type 1 diabetes accounts for approximately 5% of all diagnosed cases of diabetes, according to the CDC. And there is no known way to prevent people developing type 1 diabetes.
Oxidative stress ‘not only risk factor’
The Pittsburgh study, funded by the National Institutes of Health and published in Diabetes Care, suggests that if physicians include levels of protective antioxidants, they will have a better chance of assessing a patient’s risk of developing heart disease.The researchers collated information from the Pittsburgh Epidemiology of Diabetes Complications – a major study of type 1 diabetes cases diagnosed, or seen within one year of diagnosis, at one Pittsburgh hospital over a 30 year period.
Lead author and assistant professor of epidemiology at Pitt Public Health, Tina Costacou, explains that current clinical practice focuses on a patient’s risk factors alone to determine the likelihood of developing a disease.
But the study reveals that the combination of both good and bad factors gives a better indication. She says:
“In our study, we found that the risk of people with type 1 diabetes developing heart disease is better predicted by looking at the ratio of factors representing protection – for example, antioxidants – to those representing harm – for example oxidative stress levels.Currently, doctors most commonly determine heart disease risk by looking at the level of harmful risk factors alone, which may not give an accurate picture of the person’s risk.”
The study showed that patients with high levels of oxidative stress who also had high levels of the antioxidant vitamin E had a lower risk of developing heart disease, compared with those with high oxidative stress levels but lower levels of the protective antioxidants.A study published online at NCBI concludes that “oxidative stress may play a crucial role in cardiac and vascular abnormalities in different types of cardiovascular diseases.” And physicians continue to use it as a risk factor marker.But, the Pittsburgh study points out that although both groups had high levels of oxidative stress, they were at very different risk of developing heart disease.Prof. Costacou concludes that while further studies are needed, it may be a mistake to look at oxidative stress in isolation.
“This improved way of determining risk is not necessarily limited to the hypothesis of oxidative stress and antioxidants in terms of heart disease development; it could be expanded to other risk/protective factors and other pathologic conditions,” she says.
“If further supportive data are published, it may one day become possible to better classify a person’s disease risk and individualize treatment based on simultaneous assessment of risk and protective factors.”