The risk for stroke may be more than double in the first week following a shingles diagnosis, with myocardial infarction (MI) risk also increasing, according to research published December 15 online ahead of print in PLoS Medicine.


Caroline Minassian, PhD, and colleagues analyzed data from 42,954 Medicare recipients who were diagnosed with shingles and a stroke between 2006 and 2011. Also included were 24,237 patients with shingles who experienced an MI in the same time frame. The average patient age was 80 years; about two-thirds were women, and about 90% were white. Stroke and MI occurrence were tracked during five different periods of time in the year following a shingles diagnosis: week 1; weeks 2 to 4; weeks 5 to 12; weeks 13 to 26; and 6 months.


Compared with the risk of stroke prior to a shingles diagnosis, the risk increased for up to 3 months following a shingles diagnosis. The biggest increase, more than twofold, occurred during the first week. That risk decreased after 6 months, the investigators found. An increase in MI risk followed a similar trajectory, with almost a twofold risk occurring during the first week following a shingles diagnosis.


The study team said there was no evidence that shingles vaccinations had either prevented or aggravated stroke or MI risk. “However, this finding requires further study due to low vaccine uptake in our study population,” said Dr. Minassian.