TTHealthWatch 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 impacting on the incidence of gout, cannabis effects on driving, a viral superspreader event in Argentina, and self-knowledge of overweight and obesity.
0:50 Unique superspreader event
1:50 Isolation primarily
2:50 Model of respiratory infection
3:50 Compared to coronavirus
4:05 Cannabis products and driving
5:05 Standard deviation of lateral position
6:05 THC shown to impair driving
7:04 In conjunction with alcohol
7:44 Self knowledge of overweight and obesity
8:43 True of Blacks, more men
9:43 Idea of normal changes
10:28 Gout incidence
11:28 No diuretic use
12:30 77% of gout is avoidable
Elizabeth Tracey: What’s the effect of cannabis products on driving?
Rick Lange: Super spreaders in a virus in Argentina.
Elizabeth: What about the increasing prevalence of gout?
Rick: And do people that are overweight or obese know it?
Elizabeth: That’s what we’re talking about this week on TT HealthWatch, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a Baltimore-based medical journalist.
Rick: And I’m Rick Lange, President of Texas Tech University Health Sciences Center in El Paso, where I’m also Dean of the Paul L. Foster School of Medicine.
Elizabeth: I’m going to note for our listeners, and they’re going to note too, that today we’re actually not talking about anything that’s relative to COVID, although we are going to have some associations with COVID, I think. And so, the association is strongest with the New England Journal of Medicine, a look at this really unique virus.
Rick: This is a report of a virus that actually circulated in Argentina from November of 2018 to February of 2019. It’s called the Andes virus, but it’s a particular type called a hantavirus. People that think, “Gosh, that sounds somewhat familiar,” may recognize that about 15 years ago, here in the southwest United States, in New Mexico and Arizona, we had some hantavirus infections and it’s primarily from rodents to humans. The unfortunate thing is when humans get it they get severe pulmonary dysfunction and the mortality is high. It’s between 20% and 40%.
This report indicates that there were at least four generations of individuals that caught it from a single individual that was exposed to rodents, so there was animal-to-human transmission, and then super spreading from humans to other humans. Some of that occurred at a birthday party and social gatherings, close contacts, very similar to what we’re seeing with the coronavirus. The unfortunate thing was the mortality was about 30%.
Now, how did they deal with it? As soon as they identified a group of individuals with hantavirus, then they isolated these individuals. Before doing so, every person that got infected, infected about another 2.1 individuals. But as soon as they isolated that group, they were able to quash the virus.
So what do we learn from this? This hantavirus spreads from respiratory and aerosol droplets, very similar to COVID. It didn’t change genetically, so the social factors and the close contacts were responsible for its spread. They did identify that the people that were super spreaders were likely to have higher viral loads, very similar, by the way, to the coronavirus.
This indicates that in the future, if we identify a hantavirus, we have to be concerned about person-to-person transmissions. All the healthcare workers have to wear proper PPE, and we have to isolate individuals as well.
Elizabeth: Of course, I’m going to ask you — I’m wondering about the implications of this from the perspective of this study as a model for respiratory illnesses and the way that they can spread, and how we can interrupt highly contagious viruses.
Rick: Elizabeth, probably the only difference between this and the coronavirus is there was no genetic evolution of this particular virus, but to interrupt this, it didn’t require a vaccine at all. It just required identifying individuals and isolating them. These individuals are rarely asymptomatic, so it was easy to identify them. This just verifies what you and I have already talked about, the importance of isolation and wearing PPE for preventing spread of not only this, but the coronavirus, and we know it’s also effective for the flu as well.
Elizabeth: And it sounds like to me the other thing that’s really critically important is vigilant surveillance of emergent infections all over the globe, and potentially the use of PPE routinely in healthcare settings whenever there is a respiratory illness.
Rick: Your point’s very well taken. I mean, to be able to jump on this very early and identify individuals and their contacts and isolate them very quickly is what was able to contain it to the small number of individuals that they had compared to the coronavirus, which, by the way, has now infected over 64 million people around the world.
Elizabeth: And counting. Let’s turn to the Journal of the American Medical Association. Many states in the United States continue to decriminalize marijuana or cannabis, I guess I should call it. I have been corrected on that before, so let me try to change my term — cannabis.
This is a study that was done in the Netherlands, which is probably one of the only places where they could do such a study, between May last year and March of this year. They only had 26 participants — all young and healthy people, by the way — who volunteered to come forward and participate in a vaporization of different products of cannabis. These were THC-dominant, CBD-dominant, a THC-CBD equivalent, and a placebo.
They all sort of rolled through all of that and then they took a driving test. Of this 26 who began the study, 22 completed all 8 of the driving tests. In this driving test, they actually used a metric that I was totally unfamiliar with, but I’m sure is well known to engineers: the standard deviation of lateral position, which is a measure of weaving, and correcting, and all that sort of thing, in the lane. These tests commenced at 40 minutes and 240 minutes after their cannabis consumption.
The upshot of this study is they found that both the THC-dominant and the THC-CBD equivalent cannabis products — compared with placebo — resulted in significantly greater compromise of someone’s ability to drive, casting some question on this whole decriminalization and authorization of medical cannabis products and all that sort of thing. The authors do note that the dosage that they selected for this may not be the same as that that’s seen with a lot of these products, but it certainly raises concern, at least for me.
Rick: The two products you mentioned, the THC causes intoxication and a positive mood, and it’s been shown to impair driving. The CBD actually ameliorates those. It kind of counteracts those, so the thought was, well, gosh, if you had THC on board but also CBD both, that maybe it would impair your driving.
What this study showed was that if you have THC on board, it impairs your driving. The addition of CBD doesn’t make your driving any better. Does the CBD alone affect your driving? No, not in the small quantities that were in this study, but these quantities are much lower than what one would get medicinally, than one would get recreationally. It doesn’t simulate what happens to people that are repetitive users or frequent users. It’s not to imply that you can’t get driving impairment with CBD, but clearly CBD doesn’t improve the driving impairment that you see with even low doses of THC.
In fact, they compared it to alcohol, and this would be equivalent to a blood alcohol level of about 0.05. Remember 0.08 is considered intoxicated.
Elizabeth: Right, and the authors also note and the editorialists note that people frequently use these in conjunction with alcohol. This is something, clearly, that was not studied here, but results in, at least for me, a lot more concern about people’s ability to drive safely.
Rick: Right, Elizabeth, and they reference other studies that show that at low doses of alcohol, the addition of THC impairs your driving more than you would expect just from the serum level of the alcohol. By the way, the serum level of THC doesn’t correlate at all with driving impairment. People would just react differently to it.
Now, over 33 states have legalized marijuana. Among fatal car accidents, after alcohol I believe this is the second-most identified compound that people have in their blood system. Just a warning to individuals that either use it recreationally or medicinally, please don’t get on the road afterwards.
Elizabeth: Let’s turn to your next one. That’s in Annals of Internal Medicine.
Rick: You can’t be anywhere in the world, unless you live under a rock, that you don’t know that the incidence of obesity and being overweight is increasing, not only in the U.S., but worldwide as well. If you realize you’re overweight or obese, you’re more likely to try to lose weight. The question is, how many people are overweight or obese and don’t know it?
The authors of this particular study, to address that question, did serial cross-sectional analysis of the NHANES, the National Health And Nutrition Examination Survey from 1999 to 2016. Besides measuring weight and height, they asked people a simple question, “Do you consider yourself to be overweight, underweight, or about the right weight?”
More than 40% of US adults with overweight and nearly 10% of adults with obesity did not consider themselves to be overweight. That increased between 1999 and 2016, despite all the press that we’re hearing about increasing prevalence of obesity.
Now, what were the factors associated with that? It was especially true of Blacks, persons of low socioeconomic status. It’s not surprising a higher number of men as well, but the people that were more likely to lose weight were those that considered themselves overweight or obese, and those that got advice from their doctors to do that. But if you didn’t realize it, you were much less likely to lose weight.
Elizabeth: I find this astonishing. I just don’t understand how you could be, especially obese. I mean, the overweight definition I could understand there might be some ambiguity there, but the obesity I just do not understand what level of self-deception it takes to not identify that.
Rick: Well, the author suggests at least two things. One is, and I’ll quote, “The norms that define appropriate body weight do not align with what is considered attractive or acceptable among many cultures, especially among Black women, so culturally it’s not considered to be overweight or obese despite what the BMI says.”
Secondly is, as our weights and BMIs increase and you see more people, your idea of what’s normal changes. What used to be considered overweight 20 years ago, now, because a third of people in the United States are overweight and a third are obese, doesn’t seem quite so abnormal anymore. As a result, unless we get back to saying, “Oh, yeah. We are overweight,” or, “We are obese,” then we’re not likely to change our weight patterns.
Elizabeth: To once more draw a parallel to COVID, a profound risk factor for severe disease.
Rick: It is and unfortunately one of the things is we want to, on the one hand, evoke this positive body image. We don’t want to shame people. While on the other hand, we don’t want to tell people that, “You’re not overweight” Or, “You’re not obese” when you are, because, as you said, the long-term health implications are pretty profound.
Elizabeth: That brings us very nicely to our final one for this week, which is in JAMA Network Open. This one caught my eye because of data that’s just recently been released from the Global Burden of Disease study showing that gout is just increasing enormously worldwide.
This study takes a look at primary prevention of gout in men through modification of their obesity and other lifestyle factors. Another really big study database was used here, the Health Professionals Follow-up Study.
They analyzed just under 45,000 participants of this study with no history of gout at baseline from data that were collected in this validated questionnaire. Men were categorized to low-risk groups according to combinations of four factors: normal body mass index, no alcohol intake, adherence to a DASH type of diet — a Dietary Approaches to Stop Hypertension diet — and no diuretic use.
They looked at all of that and estimated that more than half of the incident gout cases that occurred during this time period could have been prevented by the combination of the DASH-style diet, no alcohol intake, and no diuretic use. The obesity risk factor, however, was more problematic. Basically, most of the gout that’s taking place could be avoided by modification of these risk factors and then I would also respectfully add that obesity gotten under control no doubt would have a really positive impact also.
Rick: They even broke it down a little bit more. They said if you’re obese and you modify those other three risk factors, you’re only going to decrease the risk 5%. However, if you’re normal weight or overweight, then doing those three things — getting on the proper diet, decreasing diuretic use, and avoiding alcohol — reduces your risk somewhere between 50% to 70%. Overall globally, 77% of gout is avoidable.
Elizabeth: One of the things that they cited in here is — and I didn’t know this — is that gout is the most common inflammatory arthritis in most Western countries. We know, of course, that people who experience these gout flares talk about just how incredibly painful it is. They even have a citation of the modern gout epidemic in Western countries with hospitalization rates and cost due to gout doubling in the U.S. and elsewhere. I have seen people who’ve been experiencing a gout flare and it just does not look like any fun.
Rick: It doesn’t, and, Elizabeth, let’s get a little bit more specific. The DASH diet specifically, it’s a diet high in fruits and vegetables, low-fat dairy products, and low in red or processed meat and sweetened beverages. If you’re looking for a diet that decreases the incidence of gout to help avoid the gout epidemic that you referred to, that’s the diet, as well as minimizing alcohol intake. Diuretic use, what happens is you reabsorb the uric acid, which obviously is what causes gout. Avoiding that as your antihypertensive medication, if you have gout and hypertension, changing to a different one can be beneficial as well.
Elizabeth: On that upside, on that note, that’s a look at this week’s medical headlines from Texas Tech. I’m Elizabeth Tracey.
Rick: And I’m Rick Lange. Y’all listen up and make healthy choices.