By Lisa Farr, M.Ed, Director, Exercise Physiology Core Lab
Interview with: Katie Love, MD
Type 1 diabetes occurs when the insulin-producing beta cells of the pancreas are damaged through an
auto-immune process. This process happens in genetically susceptible individuals and is probably
triggered by one or more environmental factors, such as viral infection. Over time, once enough of the
beta cells are destroyed, blood glucose begins to rise, and the diagnosis of type 1 diabetes is established.
Most people are diagnosed as children, teens, or young adults.
Mortality is three times higher in people with type 1 diabetes than the general population, and the main
driver of this is cardiovascular disease. Individuals with type 1 diabetes are at a 3-10 fold increased risk
of cardiovascular disease compared to the general population, and they tend to develop it at younger
ages. This risk increases with poor control of blood glucose, referred to as “glycemic control.”
Best estimates indicate that over 75% of adults living with type 1 diabetes are not achieving optimal
glucose control.
Most people with type 1 diabetes develop insulin resistance. Insulin resistance means that cells in
multiple parts of the body, including the muscles, liver, heart, and brain, don’t respond well to insulin.
The vascular system takes a hit in diabetes, in part related to insulin resistance.
We know that insulin resistance and poor vascular health are more common when people don’t
exercise. We also know that blood sugar is harder to control under these conditions.
Exercise is an extremely potent intervention for improving vascular health and blood glucose regulation.
Some, but not all, studies show that people with type 1 diabetes who exercise spend more time “in
range” (ie at goal glucose levels) on days they exercise when compared to days they don’t. So a person
with type 1 diabetes could see a daily benefit of being an exerciser. But there are also important long
term benefits of exercise—exercise has been shown to decrease cardiovascular disease event rate, and
improve all-cause mortality in type 1 diabetes.
Unfortunately, people with type 1 diabetes are less likely to exercise than the general population.
One of the questions this study will seek to answer is—what happens to vascular health and insulin
resistance if a person with type 1 diabetes does begin an exercise program? And sticks to it? What
happens to blood glucose control?
It will also examine these same questions in individuals who are prescribed a medication called
dulaglutide. Dulaglutide also potentially has positive effects on insulin resistance and the vascular
system. Perhaps it could be cardioprotective in type 1 diabetes?
Thus, the overarching goals of this study are to better understand how and in what ways exercise or this
medication might help people with type 1 diabetes.
Another goal is to better understand the barriers people with type 1 diabetes face when beginning or
sticking with an exercise program.
Questions and Answers with Katie Love, MD, a UVA Endocrinologist and Principal Investigator for
HSR210198-Therapeutic Strategies for Microvascular Dysfunction in Type 1 Diabetes
Question
Why did you want to study this issue?
Answer
I’m an endocrinologist. But I’m also someone living with type 1 diabetes. I was diagnosed at the age of 4.
So in addition to the scientific interest, and the clinical interest in learning more to provide better care
for my patients, I have a personal interest.
There are a few studies that show that people with type 1 diabetes live longer, healthier lives if they
exercise. And that individuals with diabetes can better control blood sugar and reduce their risk of
cardiovascular disease if they exercise. But overall I’ve been surprised by the lack of research—most of it
has been in type 2 diabetes.
People living with type 1 diabetes are at a much higher risk for cardiovascular disease than the general
population. It’s the leading cause of death in type 1 diabetes. And we know the risk is highest when
glucose control is poor. Yet about 75% of adults with type 1 diabetes are not meeting goals for glucose
control.
We know that poor glucose control increases the incidence of diabetes complications, and results in an
unhealthy vascular system. We know that type 1 diabetics develop something called insulin resistance,
and that insulin resistance predicts many of the complications we see in diabetes, including
cardiovascular disease. Exercise and certain medications have both been shown to improve insulin
resistance and cardiovascular disease in type 2 diabetes. The hope is that this will be similar in type 1
diabetes.
We think we can improve vascular health and reduce risk of cardiovascular disease and other diabetesrelated complications with exercise, and perhaps also with a certain class of drugs called glucagon-likepeptide-1-receptor agonists (GLP-1 RA’s). This study will examine both (as well as placebo) by doing a
variety of tests at baseline and again after 14 weeks of intervention. In addition, we’ll do a number of
surveys to get a sense of what people’s barriers to exercise are. We’ll also do these 3 months after the
study has ended, as we are very interested in who continues to exercise and who doesn’t and why.
Question
So what do you think is the real-life application of your study?
Answer
I think research like this ultimately helps us provide better care for our patients. It drives us to do more
research—to better understand the mechanisms involved, which can allow us to develop better
therapies to prevent the cardiovascular conditions so common in type 1 diabetes.
I think the surveys we are doing will also be very important. As health care clinicians we sometimes
assume we know why people don’t exercise, but we’re not always correct. For example, most clinicians
think people with type 1 diabetes exercise less than the non-diabetic population because of fear of
hypoglycemia. But some small surveys have not borne that out. It appears that people with type 1
diabetes don’t exercise enough for the same reasons as most people- things like time and motivation.
We’re hoping to gain more insight into that question with this study—particularly because we’ll track
their exercise during the study period and after it has ended.
Question
Can you describe the basics of the study procedure?
Answer
We are recruiting people with type 1 diabetes between the ages of 18 and 40 who are not regular
exercisers but are otherwise healthy. Enrolled subjects will be randomized to one of three groups—
exercise, medication, or placebo. The exercise intervention is 14 weeks of supervised high intensity
interval training on a stationary bike. We chose high intensity interval training because previous studies
have shown it is more effective while also being less likely to cause hypoglycemia. The medication and
placebo groups will receive weekly injections.
We’ll do a variety of tests on the subjects at baseline and repeat these 14 weeks later after they’ve been
exercising or taking the medication/placebo. We’ll measure fitness with a VO2 peak test; body
composition with a Bod Pod, and we’ll do a number of different labs. Some labs are specific to diabetes,
such as tests to determine how well the pancreas is working (C-peptide level and blood sugar control),
and others are related to cardiovascular risk and overall health. Subjects will wear a continuous glucose
monitor for 10 days at the beginning of the study and again at the end—this provides information about
glycemic variability. We’ll do a test called an insulin clamp which allows us to measure insulin sensitivity.
We’ll study blood flow by performing ultrasounds of the heart and the leg muscles. We’ll look at how
well the vessels dilate and respond to insulin. And we’ll look at the relationships between vascular
perfusion, fitness, insulin resistance, and glucose variability.
We will get a lot of useful information from this study and we do share results with our subjects, so they
will get a lot of useful information too. And for those randomized to the exercise program—well, 14
weeks of supervised exercise is a great jump start!
While catching up with Dr. Love we took the time to get a little personal too.
Question
Are you an exerciser Dr. Love?
Answer
I am! My parents pushed this my entire child hood as they believed in the health benefits. I spent my
childhood dancing—hip hop!—and then became a runner in my teens. I ran all through high school,
medical school, and residency—it was great stress relief. I’m still a runner but now that I have 2 little
ones in addition to being a Doc it is harder to make time. My husband and I try to support each other’s
exercise and we’ve purchased a home treadmill to make it easier. We try to do outdoorsy active things
with our kids to set a good example.
Question
What advice do you give your patients about exercise?
Answer
I share that I have type 1 diabetes too…and that for me too it can be challenging some days to fit it
in…but that my glucose control is so much better regulated if I exercise every day. Exercise really allows
you to live your best life. If there is one thing I would encourage everyone to do—people with type 1
diabetes or not– it would be exercise. There is not a drug I could give that would mean more to health.
