Shingles, a reactivated form of the chickenpox virus, is a painful rash that afflicts many people decades after the initial chickenpox infection. Now, we have data that shingles increase heart attacks (myocardial infarction) and strokes. This is more evidence that we need to end chickenpox with the chickenpox vaccine, and reduce the risk of shingles in those who have had chickenpox with the shingles vaccine.
Let’s take a look at shingles and this new study.
What is shingles?
One of the consequences of contracting chickenpox, a virus called Varicella zoster, is that the it is not destroyed by the body’s immune system in most individuals. Once the symptoms of chickenpox disappear, the virus hides itself in various nerve cells. The virus then remains hidden from the body’s immune system.
As a result of unknown factors, although stress or other infections may be involved, the zoster virus reactivates and moves along the nerve bundles, and causes a second infection, called shingles (see Note 1), which has much more serious consequences to the patient. Even though the body generated an immune response to the original zoster infection, after several decades, the response is either weakened or disappears.
The reactivated virus moves along the nerves to the skin. At that point, it causes significant pain followed by a chickenpox like rash. Usually, shingles happens when the patient is older than 50, although it can happen at any time, occasionally even in young adults.
Shingles is an entirely unpredictable disease. It really appears at random points in time in response to unknown variables.
Once shingles appears, it can be incredibly painful, depending on the location of the outbreak. It can cause a blindness, disfigurement of the area infected, permanent pain, and other conditions.
Antivirals are the primary treatment for shingles. However, antiviral effectiveness is limited to 24-72 hours after initial diagnosis. This might not allow most individuals to get diagnosed by their doctor. The initial symptoms may even appear like acne or some other skin condition, which many people might ignore.
There are two ways to prevent shingles. First, prevent a chickenpox infection in the first place. The chickenpox vaccine is part of the CDC recommended vaccine schedule, and as a result, the rate of chickenpox infections in the USA, and many other countries, has dropped significantly. Chickenpox incidence has dropped by 87% from the 4 million cases a year prior to vaccine availability (1994-95) until today.
Furthermore, chickenpox mortality has dropped by 99% from the pre-vaccine era.
A shingles vaccine is also available, and it remains only way to prevent a shingles infection. The vaccine boosts the immune system with a new immunization against the zoster virus. Zostavax (a shingles vaccine available in the USA) has been approved by the FDA for prevention of shingles in 50-59 year olds (and it has previously been approved for 60-69 year olds). If I had contracted chickenpox, I’d ask for the shingles vaccine even in my 40’s. But that’s not medical advice.
So let’s be clear about a couple of things. First, you are only at risk for shingles if you contracted chickenpox. Second, children vaccinated against chickenpox probably will never, ever contract shingles. Is this clear? Chickenpox vaccine prevents chickenpox AND shingles.
Shingles increase heart attacks and strokes
A study published in the Journal of the American College of Cardiology, examined the health records of 519,880 patients between 2003 and 2013. Amongst that group, 23,233 individuals suffered a bout of shingles. The authors then compared that group with a similar-sized group who had never contracted shingles
The researchers accounted for confounding risk factors such as age, blood pressure, diabetes, cholesterol level, tobacco smoking, alcohol intake, exercise and socioeconomic class.
The research team found that shingles raised the risk of stroke alone by 35%. And it raised the risk of heart attack alone by 59%. They found that the risk of all cardiovascular events, heart attack and stroke, was 41%
Individuals under the age of 40 who had contracted shingles were at the greatest risk of stroke. You should consider the shingles vaccine if you’re that age.
The authors concluded:
In conclusion, we have demonstrated that HZ (herpes zoster) significantly increases the risk of stroke and MI (myocardial infarction) even after rigorously adjusting possible confounding factors in a large population cohort. In propensity score-matched analysis, HZ raised the risks of the composite of cardiovascular events, stroke, and MI by 41%, 35%, and 59%, respectively. The risks were especially high in the relatively young who have fewer risk factors for atherosclerosis. Furthermore, there was a substantial temporal link between HZ and the occurrence of stroke and MI.
Shingles increase heart attacks – the summary
This large sized study gives us robust evidence that shingles can substantially increase the risk of heart attacks and strokes. It’s a good thing that we have the technology to prevent shingles.
First, we can prevent the original chickenpox infection with the chickenpox vaccine.
Second, if you contracted chickenpox, we can prevent shingles with the shingles vaccine.
Here are your choices – prevent the virus from attacking you in either form. Or let shingles increase heart attacks and strokes later on. The decision is easy – vaccines.
- Shingles is often called herpes zoster despite being the same exact virus. Since they appeared as two different diseases, they were given two different names. Despite the confusing names, the Varicella zoster virus is the cause for both chickenpox and shingles.
- Kim MC, Yun SC, Lee HB, Lee PH, Lee SW, Choi SH, Kim YS, Woo JH, Kim SH, Kwon SU. Herpes Zoster Increases the Risk of Stroke and Myocardial Infarction. J Am Coll Cardiol. 2017 Jul 11;70(2):295-296. doi: 10.1016/j.jacc.2017.05.015. PubMed PMID: 28683973.