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 standards for osteoporosis screening, PET and aortic aneurysm prediction, HbA1c in women of reproductive age, and atrial fibrillation in the hospital.
Program notes:
0:40 Inflammation of the aorta
1:41 Tested in people with giant cell arteritis
2:41 All large arteries
2:52 Performance measures for osteoporosis
3:52 Use in all scenarios
4:52 No DEXA in women younger than 65 not at risk
5:46 Atrial fibrillation in the hospital and its recurrence
6:46 14 day EKG monitoring
7:27 Hemoglobin A1c in younger women
8:30 Accounting for gender differences
9:30 Because younger women menstruate
10:30 Red blood cell turnover
12:02 End
Transcript:
Elizabeth: How good are the benchmarks for screening for osteoporosis in adults?
Rick: Assessing inflammation of the aorta.
Elizabeth: How do we account for increased risk of health consequences of type 2 diabetes in younger women?
Rick: And if you have atrial fibrillation when you're in the hospital, are you more likely to get it later?
Elizabeth: That's what we're talking about this week on TTHealthWatch, 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, we're spending a lot of time in Annals of Internal Medicine this week. Why don't you go ahead and start with one of yours?
Rick: Let's talk about this inflammation of the aorta. It's a relatively rare disease called giant cell arteritis. This particular one affects the large arteries -- so the ones to the head -- and it can actually cause people to lose their vision, or inflammation of the largest artery i.e. the aorta, the one that leads from the heart to the rest of the body.
What happens is there is an acute episode where there is an inflammation and then subsequently over the next months or years, especially in the aorta, that inflammation can lead to continued weakening of the aorta in an aneurysm form. We know that if an aneurysm gets to be a certain size, it's more likely to burst.
When you have someone that has inflammation of the aorta, can you use some test to predict whether they are more likely to develop an aneurysm? We know that positron emission tomography, called PET scanning, can detect inflammation pretty much anywhere in the body. They said, "Maybe we can use that, look at the aorta, and if it looks like the PET is positive, maybe that will predict outcome later."
They tested that in 106 patients that had giant cell arteritis. They did a PET scan and then they followed these individuals every year for a 10-year period. With the initial PET scan, they scored how positive it was. What they discovered was, those that had a negative PET scan were unlikely to develop an aneurysm. Those however that had a positive PET scan were 10 times more likely to develop an aortic aneurysm over the next 10 years.
Elizabeth: All right. If we are able to predict future problems, then what are we going to do about it?
Rick: I think what we can say is, "Let's say you have a PET scan that's negative; you don't need to have annual exams. But if it is positive, you need to watch the growth of the aorta." Then when it gets to be a certain size, you want to operate or intervene at that time.
Elizabeth: Let's back up just a little bit, if you will, about giant cell arteritis. My exposure to this has been that people usually have a dissection of the temporal artery in order to establish the diagnosis. When people have this, is it global?
Rick: No, it only affects the large arteries. So you're right. The vessels to the head, the carotid, or the temporal, the optic, they are all large arteries, as is the aorta.
Elizabeth: Since we're in Annals of Internal Medicine, let's turn to this issue of quality indicators for osteoporosis in adults. How well do these performance measures really stack up?
Almost 13% of adults older than 50 years of age in the United States have osteoporosis, which is a rather startling number as far as I am concerned -- largely white and Asian females, but still affecting males and females of all ethnicities. It's a major health issue and we know that. It predisposes to fractures, of course, and we know what the outcome of a lot of fractures are.
They took a look at this review of current performance measures on osteoporosis because these are used to inform physicians, payers, and policymakers in how they select what's appropriate to be doing when we're trying to assess this condition. The bad news is that they did a search looking at all of these performance measures. They identified six of them. Only one of them was found to be valid at all levels of what they call "attribution."
All right. Are we going to be able to use this in all of these scenarios where we might want to?
Rick: Here is why this is important to the medical practice. When we say performance standards, they hold us accountable to it. The government, private insurance, healthcare plans, kind of hold us accountable for these. Then you say, first of all, are they valid measures? Can you measure it? Does it mean something? Does it improve clinical care? Can you attribute it at all three levels: at the individual physician? Should they be responsible? Should the group practice be responsible, and/or should the health plan level be responsible?
It shows of the six performance standards routinely used by all of these organizations, only one of them can be attributed to all three, so again this is important information. You can't hold people accountable for something that isn't valid or that they're not responsible for.
Elizabeth: Some of their specifics that they cite in here fly in the face of common practices. For example, the ACP, the American College of Physicians, does not support the use of DEXA scans in females younger than 65 years of age who have no risk factors for osteoporotic fractures. However, there [are] many, many, many, many women who are younger than 65 years of age, who are routinely given DEXA scans to assess their osteoporosis status.
Rick: Right. The other thing is, there is insufficient evidence for screening males that are 70 years or older, yet for some plans that's a performance measure. Are you doing it in your patients? You say, "Well, wait a minute. There is no data to support that." Kudos to the authors for being really critical.
Elizabeth: Let me just also skewer another sacred cow. Here, they talk about not supporting the behavior of monitoring vitamin D levels in managing low bone mass at the individual physician or group practice level. That's another one that people are routinely undergoing all the time. I thought also the conclusion was a little disturbing because they didn't say, "Hey, here is what to do." They said, "Wow! We really need to figure out what to do."
Rick: Yep. The first place to start is to do a rigorous analysis like this.
Elizabeth: Staying again in Annals.
Rick: This is a problem that I see fairly commonly. Arterial fibrillation is the most common arrhythmia and it affects millions of people worldwide. It increases the risks of stroke and heart failure and death. Once you discover it, if the person is at risk for a stroke, you put them on anti-coagulation -- blood thinners -- to prevent them from having a stroke. There also a procedure that can cure it called radiofrequency oblation.
But what about the individual that comes in with pneumonia or they have some sort of medical stress? Or they are going to have surgery and they have it, and they have atrial fibrillation afterwards and it goes away on its own, or you may have to treat it. But does that mean that person is at risk at a time when they are not under medical stress?
These authors did a really interesting thing. They looked at three academic hospitals in Ontario, Canada -- a shout-out to our friend, Tom, that's a faithful listener from Canada -- and they estimated the risk of recurrent atrial fibrillation in individuals that never had it, except it was discovered in the hospital. Once they identified those individuals and they were sent home in a regular sinus rhythm, they brought them back in 1 to 6 months and they put a 14-day EKG monitor on them, to see if they would have atrial fibrillation.
By the way, they compared it to a group that never had atrial fibrillation in the hospital, and here is what they discovered. Those that had never had atrial fibrillation in the hospital, their risk of having it was only 5%. But if you had it in the hospital, even [transiently], your risk was about 33%. For us as clinicians, if we see the patient in the hospital and they have it, we need to follow them because if they have it after the hospitalization and they are at high risk for stroke, they should probably be on an anticoagulant.
Elizabeth: This is a really startling finding as far as I'm concerned, because a third of these folks are going to end up with this and it clearly suggests that there's an intervention that is potentially indicated.
Rick: This will change practice outright.
Elizabeth: Then, let's finally turn to a journal that we never talked about anything from before. This is called Diabetes Therapy. This is a preprint and it was presented at the European diabetes association meeting that's going on right now. This is the kind of thing I call a "duh" finding -- that is, D-U-H -- because it appears to me that this thing has been hiding in plain sight and kudos to these authors for actually bringing it into evidence.
This paper is entitled "Is the Current Cut Point for Glycated Haemoglobin (HbA1c) Correct for Diagnosing Diabetes Mellitus in Premenopausal Women? Evidence to Inform Discussion." The authors begin their paper with the statement that women are on average diagnosed with diabetes mellitus at a later age than men, but have higher mortality.
What they decided to do was look at this diagnosis based on the use of hemoglobin A1c, what is that reference range, the cutpoint, and whether there is any accounting for gender differences with regard to that. They analyzed hemoglobin A1c levels of almost 147,000 individuals who had single testing only and had hemoglobin A1c levels between 2012 and 2019. Then they replicated this assessment in six laboratories with almost a million individuals tested between 2019 and 2021.
Women who were younger than 50 years of age, who had a hemoglobin A1c testing, was lower than that in men by a mean of 1.6 mmol. When they compared that to those who were greater than 50 years of age, that was less pronounced.
They estimate that this could account for almost 35,000 undiagnosed women younger than 50 years of age in England and Wales who would be reclassified to have diabetes mellitus and they say that could contribute to up to 64% of the difference in mortality rates between men and women.
Their hypothesis is that the reason that this hemoglobin A1c is artificially lower is because women menstruate and they lose a certain amount of blood every month. Because of that, that exposure of the erythrocyte and its ability to sort of have that average level of glycation that's evident in the hemoglobin A1c is shorter, so it's artificially lower during that time.
Rick: What we use to either diagnose pre-diabetes or diabetes in terms of the hemoglobin A1c level, that reference range was based on a study of 205 individuals with type 1 diabetes and 124 controls without diabetes. That's a pretty small number and we have been using that for a long time.
Somebody took a back step and said, "Wait a minute. Let's use a larger group of individuals and see what the normal hemoglobin A1c is. Let's see if it's different for males and females." That's what this is. They showed that, "Wait a minute, overall the hemoglobin A1c in women pre-menopausal is lower, so we need to have a different standard." Kudos to them for saying as you said what the obvious is, kind of a "duh" study.
A red blood cell usually lasts for 120 days. Now, in women, the red blood cells last less because they're menstruating and they are turning over red blood cells more often. That's why the hemoglobin A1c, the glucose that's attached to that red blood cell, turns over faster and that's why the numbers are probably different. What that means is there is a lot of people walking around with early diabetes and we just don't know who they are. For the pre-menopausal women, we need to be addressing that.
Elizabeth: Absolutely. I mean, it just suggests then for a specific population there needs to be scales that are appropriate, and the only we're going to be able to develop that is by looking really carefully at what exactly is that measurement. To take that even further, this presence of what we're calling pre-diabetes for longer in women must account for this increased predilection for cardiovascular disease.
Rick: Right. Because we know what happens is if we make the diagnosis in the old standard, we say, "Oh, they have only had diabetes for 3 years." Well, actually they probably had it for 10 years and we didn't know it for the first 7 because we used the wrong standard. That's why, the hypothesis suggests, is why they may have a worse outcome, because they have had it for longer and we just didn't know it.
This applies to women under the age of 50. Over the age of 50, there is still a little bit of difference between the men and women, but it's a lot less marked.
Elizabeth: It's that finding hiding in plain sight. We are happy that you've identified this. 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.