Itching and Dialysis; New Smallpox Vaccine: It’s PodMed Double T!

Allergies & Asthma

PodMed Double T is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week. A transcript of the podcast is below the summary.

This week’s topics include atrial fibrillation and the Apple watch, itching relief for people on dialysis, a new type of smallpox vaccine, and affordability of a sustainable diet.

Program notes:

0:40 Affordability of an optimum diet

1:40 Data from 2011

2:40 A lot of people can’t afford it

3:40 About 2,500 calories per day

4:21 The Apple watch and afib

5:21 Monitor and correlate with EKG

6:22 Consequences of detecting a problem

7:15 Itching and hemodialysis

8:16 Placebo group also reported improvement

9:17 Helped itch related quality of life

10:10 A new kind of smallpox vaccine

11:11 Can have serious infections with vaccine

12:48 End

Transcript:

Elizabeth Tracey: Can we help people with dialysis who have itching?

Rick Lange, MD: Using a smartwatch to detect heart rhythm abnormalities.

Elizabeth: What about the affordability of a best diet for people worldwide?

Rick: And a new smallpox vaccination.

Elizabeth: That’s what we’re talking about this week on PodMed TT, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a medical journalist at Johns Hopkins, and this will be posted on November 15th, 2019.

Rick: And I’m Rick Lange, President of the Texas Tech University Health Sciences Center in El Paso, where I’m also Dean of the Paul L. Foster School of Medicine.

Elizabeth: Rick, I’d like to turn first to the Lancet. This was a look at something that I think is increasingly important for so many reasons. And basically, it was an analysis of the affordability of what’s called the EAT-Lancet Reference Diet. This was a diet that was developed by a number of experts a few years ago where they said, “What do we need to do to maximize the distribution of different types of foods, carbohydrates, fats, and proteins as well as the nutritive value of the diet? How can we create such a thing that’s both globally sustainable and affordable for most people?”

So they did that, and then they took a look in this study at how affordable is that for people across the globe? I was a little disappointed because they used retail prices from 2011, which seems like a really long time ago to me, for 744 foods in 159 countries. And it still remains hard for me to believe that the latest data available is from 2011. But in any case, that’s what they used.

Then, they said, “How much is this diet going to cost per day and how does that relate to each country’s mean per-capita household income?” Is it affordable? They concluded that the EAT-Lancet diet would cost about $2.84 per day of U.S. dollars, which seems really modest for most of us. The largest share of those costs was the cost of fruits and vegetables, which, of course, the diet relies quite heavily on, followed by legumes and nuts and then meat, eggs, and fish.

The most distressing thing, I thought, was they estimated that the cost of this particular diet exceeds the household per capita income for over 1.5 billion people globally. While this thing might be great in terms of health and global health, global sustainability and the environment, that’s an awful lot of people for whom it’s simply out of range.

Rick: It is, and as the article identified, most of those people are in sub-Saharan Africa and in Asia. Spending less than $3 a day on an adequate diet — a diet that’s rich in fruits, vegetables, legumes, nuts, and minimizes meats and has all the protein and nutrients, and spending less than $3 a day — that’s less than people spend on a Big Mac meal. To make this happen, we’ve got to find ways to either raise the income or to deliver nutrition in a more cost-effective way or to make the food more affordable. But unless we do that, even identifying the optimal diet and not making it available to much of the world isn’t very helpful.

Elizabeth: I thought it was interesting this diet provides about 2,500 kilocalories per day. I’m wondering about the adequacy of that for many.

Rick: What this paper is — it’s a follow up on one published in 2019 that said globally what would be the best diet to provide all the caloric needs and the nutrient needs and to make it as healthy as possible? Now that we’ve identified that diet, and as you mentioned, that diet is 2,500 calories. It’s just across the population, by the way. Some will need more. Some will need less depending upon their work and whether they’re male or female and also their age as well, but across the board, 2,500 calories would be sufficient.

Elizabeth: I’m wondering about maybe we should have a tax on high-income individuals who don’t follow the diet to help to fund it for those who really can’t afford it.

Rick: What you’re talking about is reallocating resources. We have that ability right now. We don’t do a very good job of it. Again, we need to raise the income of countries of poor-income countries, find ways of making the food more affordable, and deliver it in a more affordable way. That’s more sustainable.

Elizabeth: Let’s turn to the New England Journal of Medicine where we will spend the rest of our time. Which of those would you like to choose?

Rick: Let’s pick the smartwatch. This is an interesting study on so many different fronts. Over the coming years, we’re going to talk about more remote monitoring and using wearable devices to help monitor our health. In this particular case, they said, “Can we use a smartwatch and a routine available app to diagnose atrial fibrillation?” The reason why that’s of interest is we know that atrial fibrillation is a potential risk for stroke. Rather than doing a randomized, controlled trial, they recruited people over the web.

There were almost 420,000 participants who over an 8-month period signed up. They said they didn’t have atrial fibrillation. They would download this app and they have followed these individuals over that 8 months. It identified a possible abnormal rhythm in about 0.5%. In that 0.5%, they sent EKG leads so they could actually put them on the chest and monitor to see whether in fact they did have atrial fibrillation, and if so, did the EKG leads on the chest correlate with what was going on with the watch? Of the 0.5%, only about a fourth actually returned them with the reporting, but when it did, there was concordance that showed the same rhythm abnormality in about 70% of individuals.

What does this tell us? First of all, in the general population, atrial fibrillation is pretty rare. The follow up on this is not as good as a randomized, controlled trial. Then of those they determined had an abnormal rhythm, only a fourth of those turned back data. This shows we can do some studies from applications using smartwatches and monitoring devices using the web; however, they’re not quite as good as randomized, controlled trials. How applicable is it? That still remains to be determined.

Elizabeth: I think so. I do, also, worry about a few things, of course. I worry about people signing up to allow themselves to be monitored and to allow that data then to be transmitted all over the place. That is an invasion of privacy and it’s sort of startling to me that people aren’t more sensitive to that, I guess.

Then I wonder about the consequences of, if we detect a problem and you’ve already identified this is only going to expand. Pretty soon, it’s going to be blood sugar. It’s going to be other things that have a long-term impact on somebody’s health. Then what do we do? What’s appropriate? Is it appropriate, for example, to even penalize people for not taking steps to do the preventative things because ultimately we all pay for people who have these consequences.

Rick: That goes to your point about whether this information is protected or not. You may or may not want to have that disseminated. It may or may not have implications regarding treatment and/or things like your insurability. I agree. It was kind of an interesting study, less about the results and more about the implications.

Elizabeth: Yeah. I do predict, however, we’re going to be seeing a lot more of this what I’m going to call “crowdsourced” kind of studying.

Rick: I totally agree. Let’s talk about your paper on hemodialysis and the itching associated with it.

Elizabeth: Of course, people who are on hemodialysis and who have kidney failure, unfortunately, about 60% of them, it turns out, experience pretty profound itching. That can have a really terrible impact on their sleep. It can cause depression. It reduces their quality of life. We already know that just being on dialysis alone has a lot of deleterious impact on someone’s life, so to add itching — and especially moderate to severe itching — to that condition is really just adding more burden.

In this study, they took a look at something that’s called difelikefalin. This is a selective type of opioid agonist. They had 378 patients who were included in this study, and 82 of 158 of those in the difelikefalin group had a decrease of at least 3 points in one of their itching scales. That was almost 52%, of those folks as compared with 51 of 165 or 31% who were in the placebo group. Interestingly, at least again to me, the placebo group also reported a decrease in their itching score. We see this so many times in those placebo groups.

Other indices also established the efficacy of this treatment. I would note the treatment is intravenous, so that’s a bit of a burden, and diarrhea, dizziness, and vomiting were more common in the difelikefalin group than they were in the placebo group. So while it did look like in this phase III trial there was a benefit to this agent, I think we need to go back to the drawing board and find something a little better. That’s my opinion.

Rick: This is the first time I think we’ve actually reported on itching in now our 16th year of doing PodMed. I’m glad you picked this article because it really is a serious problem for people that are on hemodialysis. There are thousands of people on hemodialysis. As you mentioned, this is an IV medication given three times weekly. The itching was measured over a 12-week period. This decreased the number of patients who itched and what I found was an interesting thing called the “itch-related quality of life,” which is also improved. But they are developing an oral form of this medication, which I think will make it easier to take.

The side effects occurred in less than 10% of individuals. The important thing is this opioid receptor acts particularly in the periphery. It acts in the body and it doesn’t cross the blood-brain barrier, so it doesn’t have potential for abuse, for example. So it’s a unique agent. It is a disease that really does affect quality of life. This is the only available treatment. We’ll get newer agents, oral agents, agents that are better tolerated, perhaps, and even have a higher efficacy.

Elizabeth: I thought it was interesting that a large number of people did not respond to this treatment, even in the intervention group.

Rick: There may be more than one mechanism for the itching.

Elizabeth: We need to understand that a little bit better, but hope for some, so that’s a good thing. Let’s turn to our final one and that is a different kind of smallpox vaccine.

Rick: Most of us don’t even think about smallpox vaccines anymore because we’re not getting vaccinated anymore. Elizabeth, you and I did, but the last smallpox infection was reported in Somalia in 1977. It’s thought to be eradicated; however, there’s concern it could be used by bioterrorists or it could emerge on its own. We have a number of people that aren’t vaccinated now.

That particular infection, smallpox, is a variola viral infection. It’s closely related to what’s called vaccinia. For those of us that got the smallpox, remember this vaccinia, it’s a live virus. It’s injected underneath the skin, and it causes a pustule because the virus is actually replicating and causing inflammation, and we develop an immune response to that inflammation. That cross-reacts and protects us from smallpox, a closely related virus.

The trouble with using that — because it’s a live, attenuated virus — is that people have immune disorders or HIV infection or cancer, or even atopic dermatitis, can have serious, life-threatening infections as a result of it. Let’s try to develop another vaccination that doesn’t have these characteristics, but how do you test it because smallpox isn’t available? That’s where this particular study is unique. Here’s what they did.

We have a number of troops that are going to go over to South Korea. We would typically give them a smallpox vaccination, but let’s give them this new, modified vaccine called modified vaccinia Ankara, MVA. Let’s give it to them beforehand, and the unique thing about this vaccine is it only replicates once. They gave this modified vaccine in half the troops. Those that received the modified vaccinia Ankara, the MVA, developed neutralizing antibodies, and then when they gave them the smallpox vaccine, they did not develop the welt. Almost 100% of them developed no welt at all, but they had the antibodies. That suggests this will be effective for treating smallpox.

Now, the nice thing about this particular vaccine is — because it doesn’t replicate — you can attach other things to it to develop immunizations against other potential infections. This is a really unique study called a phase III efficacy study done in about 420 individuals that suggests we may have a new way of developing a vaccine for smallpox and related vaccinations without giving a live virus.

Elizabeth: Excellent. I’m not sure what else to say about that other than that sounds like really good news. On that note, then, that’s a look at this week’s medical headlines from Texas Tech. I’m Elizabeth Tracey.

Rick: I’m Rick Lange. Y’all listen up and make healthy choices.

2019-11-16T14:00:00-0500

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