For some people, the body's reaction to stress may raise the odds of developing high cholesterol, the results of a new study suggest.
Researchers in the U.K. found that healthy middle-age adults whose cholesterol rose in response to a stressful task were more likely than their peers without this increase to have high cholesterol several years later.
It's been known that blood cholesterol can show a short-lived rise in response to stress, study co-author Dr.Andrew Steptoe told Reuters Health. The new findings, he said, suggest that these transient increases may predict long-term elevations in cholesterol.
A number of studies have linked chronic stress to a higher risk of heart disease, and it's possible that stress-related changes in cholesterol contribute to this, according to Steptoe, who is based at University College London.
Steptoe and colleague Lena Brydon report the findings in the journal Health Psychology.
To see if stress-related spikes in cholesterol can have long-range effects, the researchers followed 199 middle-aged adults over 3 years. At the start of the study, participants performed two moderately stressful computer-based tasks; blood samples were taken before and after the tests to measure any changes in cholesterol levels. The men and women were then divided into three groups based on the extent of their cholesterol response.
Three years later, participants had their blood cholesterol measured again. Those in the group with the greatest cholesterol response to stress were the most likely to have high cholesterol.
Overall, 56 percent had a total cholesterol level that surpassed the cut-off for diagnosing high cholesterol, compared with only 16 percent of the group whose cholesterol levels had been least affected by stress.
Changes in metabolism
Even when the researchers weighed other factors such as age, body weight and smoking, the group with the highest stress response was 13 times more likely than the group with the lowest response to have high cholesterol 3 years later.
They were also four times more likely to have high levels of LDL cholesterol, the "bad" form that contributes to artery-clogging plaques.
The findings suggest that chronic stress can contribute to high cholesterol in some people, though the reason is unclear, according to Steptoe and Brydon.
One possibility, they note, is that changes in metabolism in response to stress ultimately cause the liver to boost production of LDL particles. There is also evidence that stress can temporarily limit the body's clearance of cholesterol from the blood.
According to Steptoe, it's possible that such effects could be modified if people changed their conscious reactions to stress.
Stress management, he noted, has been shown to lower levels of the stress hormones cortisol and epinephrine. Steptoe said he is not aware of any studies that have tested whether the same is true of cholesterol levels.