Dr. Roach: High troponin levels follow after a bout of food poisoning

Dear Dr. Roach: I am a 77-year-old male who apparently suffered a case of food poisoning. I say apparently because no cause was ever discovered for the uncontrollable vomiting and diarrhea that lasted for a whole day, then reoccurred briefly the following morning.

A trip to the emergency room involved many tests, but nothing turned up except a troponin level well over 0.04 ng/mL, which prompted an angiogram that didn’t reveal any problems with my heart. What else might have caused my high troponin level?

— Anon.

Dear Anon.: A troponin level is a standard blood test usually used to evaluate patients for heart attacks. However, newer, highly sensitive assays have proven that tiny levels of troponin may be detected in nearly everybody.

A level above 0.04 ng/mL is often used as the cutoff for the “normal” range, but depending on the assay and population studied, a few healthy people may have levels above this. People with heart attacks may have troponin levels in the hundreds or thousands. The higher the troponin level, the more muscle damage there is.

The fact that your coronary arteries show no blockages is very good news. Other types of heart damage may also cause a high troponin level, including inflammation of the heart (myocarditis) and heart failure. Also, critical illness can cause high troponin levels (at much higher levels than you may have had) in people who don’t have heart blockages. (A median of 0.57 ng/mL was found in people with septic shock.)

I found a long list of reported causes of elevated troponin levels, but gastroenteritis was not on the list. I suspect your body was working so hard to fight off the infection without enough fluid that your heart needed more oxygen-carrying blood than it got, leading to tiny amounts of injury to the heart muscle despite normal heart arteries. You can lose a lot of fluid with vomiting and diarrhea, and people at age 77 don’t have as much reserve as they did when they were younger.

Dear Dr. Roach: I’m a 56-year-old male who never had the chicken pox. When the first of my children was born, I had blood tests done to see if I’d ever been exposed. I had not, so I received the chicken pox vaccine in case my children were to expose me. Twenty-five years later, many friends and colleagues have either received the shingles vaccine or have had a shingles outbreak. My question to you is: Since I’ve never had chicken pox, do I still need the shingles vaccine?

— D.S.S.

Dear D.S.S.: Yes, the shingles vaccine is still recommended. Shingles is a recurrence of the chicken pox virus. The vaccine you got was a live but weakened form of chicken pox. It has a lower risk of causing shingles than getting the actual chicken pox, but there is still a risk.

Shingles is so bad that the vaccine is absolutely worth it, in my opinion. Even people who have had the old, one-shot vaccine (Zostrix), as well as those who don’t recall having had chicken pox, should get the new, two-dose vaccine (Shingrix), which is not a live virus. It’s better to just get the vaccine than get blood testing done in people who don’t recall getting chicken pox as a child.

Readers may email questions to ToYourGoodHealth@med.cornell.edu.