A history of herpes zoster, or shingles, was found to have an apparent association with an increased risk of stroke and heart attack, according to a research letter published july 3 in the journal of the american college of cardiology.

researchers in south korea, led by sung–han kim, md, phd, used the national health insurance service's "medical check–up" database to identify patients with newly diagnosed shingles, stroke and heart attack using the relevant international classification of disease–10 diagnostics codes. a total of 519,880 patients were followed from 2003–2013. there were 23,233 cases of shingles during this period. the final cohort of 23,213 was matched with the same number of shingles–free control subjects.

shingles was found to raise the risk of a composite of cardiovascular events including heart attack and stroke by 41 percent, the risk of stroke by 35 percent and the risk of heart attack by 59 percent. the risk for stroke was highest in those under 40 years old, a relatively younger population with fewer risks for atherosclerosis. the risks of both stroke and heart attack were highest the first year after the onset of shingles and decreased with time. however, these risks were evenly distributed in the shingles–free group.

"while these findings require further study into the mechanism that causes shingles patients to have an increased risk of heart attack and stroke, it is important that physicians treating these patients make them aware of their increased risk," kim said.