The researchers found that after a week of diagnosis, stroke risk nearly doubled. While heart attack risk rose as well, it was not as significant. Within six months risk for both conditions normalized.
Study author, Caroline Minassian, Ph.D., said, “The study highlights when patients with shingles may be most vulnerable. If we know when these events are more likely to happen, this may potentially help to prevent strokes and heart attacks in older people.”
Shingles is caused by the same virus that causes chickenpox, and previously having chicken pox increases the risk of shingles in the future. Seniors commonly develop shingles, but it is a treatable condition. Furthermore, to reduce their risk they can receive a vaccine for it, which cuts their risk by half and significantly reduces symptoms.
Stroke and heart attack risk was assessed on five different occasions during the study period. Up to three months after shingle diagnosis, stroke risk significantly increased with the highest increase occurring within the first week. After six months, that risk reduced. Heart attack risk saw the same jump and decline.
Although the study found a link between shingles, stroke and heart attack risk, they did not explore the mechanisms as to why shingles increases the risk of heart events. Minassian did explain, “However, possible reasons might include the overall higher level of inflammation in the body associated with a viral infection, or [virus-induced] blood vessel damage. Acute increases in blood pressure relating to shingles-associated pain or stress may also play a role.”
Researchers also explained that shingles is not the only illness linked with cardiovascular risk; influenza, too, can increase the risk of heart events.
The findings were published in PLOS Medicine.