Body Roundness to Predict Cardiovascular Disease; Myopia on the Rise

TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine in Baltimore, 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.

This week’s topics include body roundness to predict heart disease, blood transfusions following MI, suicide care in primary care, and increasing rates of myopia.

Program notes:

0:40 Body roundness as CVD predictor

1:41 China Health study

2:40 Widespread applicability?

3:34 Global prevalence of myopia

4:32 Almost 40% of children and adolescents by 2050

5:30 In infants and kids, neural plasticity

6:31 Prevention of myopia?

7:27 When do people who’ve had an MI need transfusion?

8:31 Hemoglobin determines

9:16 Suicide care in primary care

10:16 Model employed with random start dates

11:22 Suicide care in combination with other screening

12:29 End

Transcript:

Elizabeth: Should we be concerned about an increasing rate of nearsightedness in children and adolescents?

Rick: When do individuals who have had a heart attack need a transfusion?

Elizabeth: Can we intervene in suicide prevention in primary care?

Rick: And using body roundness index to predict cardiovascular disease.

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: Rick, how about if we start with the Journal of the American Heart Association because this issue of, gosh, how do we describe — let me call it obesity — in a way that’s meaningful for people, has been front and center for lots of folks and this is an index that’s looking at something called body roundness.

Rick: Right. It’s clear that if you look globally the incidence of obesity has gone up. The question is, well, how do you define obesity? Is it absolute weight and then we use what’s called the body mass index? But in the Asian population, the body mass index isn’t as accurate in predicting subsequent cardiovascular disease, so they have developed what’s called the “body roundness index” that looks at the waist circumference in proportion to the height. This is a complicated equation that requires a computer.

At least in the Asian population, it looks like this body roundness index may be a better predictor of cardiovascular disease. These investigators looked at almost 10,000 participants in what’s called the China Health and Retirement Longitudinal Study (CHARLS). These individuals had repeated body roundness index measurements from 2011 to 2016 and they followed them up to 2020. They actually did the trajectory and they looked at the incidence of cardiovascular disease.

What they determined is that based upon the body roundness index, compared to the lowest level, those that were in the “moderate” trajectory had a 22% increased risk of having cardiovascular disease. Those at the highest level had a 55% increase in cardiovascular disease. When they looked at the conventional risk models to predict who would have cardiovascular disease — what’s your cholesterol, do you have high blood pressure, do you smoke, and what’s your age and gender — the addition of the body roundness index improved the modeling.

Elizabeth: I would also point out that the Asian population, of course, has already been well-defined with regard to visceral fat deposition and that a smaller amount of that in an Asian person is a good deal more problematic than it is in people of other ethnicities. So, I’m wondering about the widespread applicability of body roundness.

Rick: Well, the nice thing is that there are two easy measurements — that is, you measure their waist and you determine what the height is. But you’re right, it’s a surrogate measurement of what visceral fat is. Now, obviously, to measure visceral fat takes more complicated equipment and measurements. The implication is that the visceral fat is more related to cardiovascular disease than other fat and it’s probably because it’s more proinflammatory. In my opinion, it’s a pretty simple way of a surrogate measurement of visceral fat in the Asian population.

Elizabeth: Right, in the Asian population and that’s a really important caveat. Clearly, to me, we do not have our arms around this yet. I applaud the discussion and have thought, as you have for a long time, that BMI is really pretty suspect when it comes to risk prediction or a measure of adiposity. So we do need something else.

Rick: Right.

Elizabeth: Let’s turn to the BMJ and take a look at this global prevalence trend and prediction of myopia in children and adolescents, a study looking from 1990 and projecting to 2050 — another issue that disproportionately impacts Asian people. This issue of myopia, or nearsightedness, is a global public health concern and that’s because there are just so many more people who are experiencing it. This is a meta-analysis of 276 studies looking at 5.5 million participants from 50 countries across all 6 continents.

What they have shown is that when they look at this from 1990 they find a gradual increase in pooled prevalence of myopia, ranging from 24% to almost 36%, observed during that 1990 to 2023 period, with projections saying that by 2050 we could be at almost 40% of children and adolescents experiencing myopia.

Way more people in East Asia experience this, those who are in urban areas, and females. Then with regard to adolescents and high school students, these are numbers that are approaching 50%. We need to be concerned about this and what are the factors that are associated with it. Clearly, they are fingering decreases in outdoor activities and increases in screen time as primary factors that are causing this particular problem.

Rick: For those that may not know what nearsightedness is, that’s when objects up close look pretty clear, but objects far away look pretty blurry. The reason why you’re concerned about that is not just because it requires glasses to see distant objects, but also because nearsightedness puts an individual at increased risk of having retinal detachment, glaucoma, cataracts, and other serious eye conditions.

In infants and young kids, there is a lot of neural plasticity. The brain is changing and how it interacts with the eye is changing. It appears that individuals that spend a lot of time looking at things up close and less time looking far away are more likely to develop myopia. That’s why myopia has an increased incidence in people that live in the city, at households that are more educated, and in individuals who are in higher-income countries.

Elizabeth: There is a correlation between duration of education and the occurrence of myopia. They say that earlier introduction to formal educational practices at a young age may also influence this development.

Rick: Right. Because these kids are inside, they are looking at materials up close — whether they are books or computers or screens — and they are spending less time in activity. There is a lower incidence in countries like Africa, where kids spend a lot of time outdoors, especially at young ages. Elizabeth, recommendations for preventing this or helping to stave off this increase?

Elizabeth: I went and did some additional research on this one because I was wondering if someone is already looking to be on that trajectory toward a development of myopia, which clearly is a progressive condition, does exercise and exposure to outdoor light stabilize it or ameliorate it?

The answer is, yes, it does. I think, clearly, we need to get these kids outside. The question is, is it the light exposure or the physical activity? It sounds like it’s both. I’m sort of thinking in my head, “Gosh, maybe we ought to move a lot of, like, classrooms outside and give them all standing desks, or something like that, in order to stave off this condition.”

Rick: Right. If we’re going to start education at a very young age, we need to try to reduce the excess burden of having things like homework [and] more time outside where you’re using your far vision and exposed to physical activity as well.

Elizabeth: Right. Let’s turn back to Annals.

Rick: When do individuals with a heart attack need a transfusion? Oftentimes when people have a heart attack, those people may present to the hospital and be anemic at baseline. Do you need to give them transfusions to help improve their overall outcome after they have been treated for a heart attack?

The normal hemoglobin for a male is about 14 to 18. For a female, it’s about 12 to 16. When they’re less than 10, we consider them anemic. When they’re less than 7, we consider them particularly anemic. Outside of a heart attack, we don’t transfuse somebody unless their hemoglobin gets to be less than 7. Why is that? Because when we were more liberal with it, it actually increased the risk of sepsis, infection, and transfusion-related complications. It also increased the risk of death.

But in a previous study that looked at transfusions in people with myocardial infarction, if you wait until they have a hemoglobin of 7 or 8 and you don’t treat it, they have an increased risk of a poor outcome over the next 6 months.

This data was collected in about 3500 individuals, some of whom had a hemoglobin of 7, some had a hemoglobin of 8, some 9, and some 10. What’s the overall outcome? What they determined was that if you had a hemoglobin of 7 or 8, those individuals were more likely to have complications over the next 6 months. But a hemoglobin of 9 or 10, those individuals did much better and there was really no difference between having 9 or 10.

Elizabeth: Talk to me about this finding within the context of your practice and what you’ve observed.

Rick: There was, again, a lot of confusion. This data provides information that’s really actionable. If someone comes in with a heart attack and either they have bleeding during the hospitalization or they come in anemic, I’m not going to transfuse them if they have a hemoglobin of 9 or above. But below that, I can lower their 30-day risk by at least getting them up to 9. This actually does change practice.

Elizabeth: Finally, then, we’re still in Annals of Internal Medicine. We’re going to take a look at the effectiveness of integrating suicide care in primary care practices.

It’s been noted that more than 40% of persons who die by suicide see a primary care clinician in the month before their death, and more than 75% of them in the year before their suicide death. It sure sounds like it’s an opportunity to kind of assess this in folks and see if there is a way to head it off.

I have to say that I look at this within the context of the increasing number of expectations we have of primary care, and taking a look at a multitude of risk factors and attempting to intervene. In this case, they have a strategy that they call suicide care in these primary care practices, versus usual care — 19 primary care practices within a large healthcare system in Washington State. They randomly assigned launch dates, looking at adult patients — those 18 years of age or older — with primary care visits from January 2015 to July 2018.

The intervention, of course, was this so-called suicide care model. This was EMR-based clinical decision support, monitoring supported implementation of depression screening, suicide risk assessment, and safety planning on the part of the patient. Then they looked at, “OK, was there, in their EMR or insurance claims data, any suicide attempts or deaths within 90 days of a visit?”

During their usual care, they had 260,000 patients making these primary care visits, and during their suicide care period 230,000 patients, plus or minus. What they were able to show is when they implemented the suicide care, suicide attempts within 90 days decreased from 6.57 to 4.93 per 10,000 patients.

Here is the rub for me. The suicide care was implemented in combination with care for depression and substance use disorder. I think it’s really hard to tease out where is the chicken and where is the egg.

Rick: Elizabeth, not only that, but this was a pretty intensive plan. You mentioned that it involved EMR and performance monitoring, but what happened is the primary care physicians did some screening of the individuals there at the time. If they expressed any suicide ideation or previous suicide attempts, they were connected that same day to licensed clinical social workers trained to function as integrated mental health clinicians. This was pretty intensive. It’s hard to imagine that we could actually make this occur in most clinical practices.

Elizabeth: More work needed. On that note then, 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.

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