Considering the Heart | Part 1 | Type 1 Diabetes

Laddie_Head SquareThose of us with any type of diabetes are constantly told that we are at high risk for cardiovascular disease (CVD). As someone who is in relatively good health despite 39 years of Type 1 diabetes, I have been quick to play the “Not Me” card. Although I follow through with all of the tests that my doctors recommend, I do them with the conviction that I don’t have heart disease. My internal dialog has been along the lines of:

♥︎  Heart disease affects people with Type 2 who have metabolic syndrome. Metabolic syndrome is defined on Wikipedia as “a clustering of at least three of five of the following medical conditions: abdominal (central) obesity, elevated blood pressure, elevated fasting plasma glucose, high serum triglycerides, and low high-density lipoprotein (HDL) levels. Metabolic syndrome is associated with the risk of developing cardiovascular disease.”

♥︎  I have diabetes because of an autoimmune attack on my pancreas. That doesn’t have anything to do with metabolic syndrome or heart disease. I am not overweight nor do I have other characteristics of metabolic syndrome.

♥︎  I understand that heart disease can result from “poorly controlled” Type 1 diabetes. My A1c’s are well within the ADA guidelines and have been for a long time. My diabetes is “well controlled.”

♥︎  All of the recommendations for addressing cardiac risk factors for people with diabetes are based on research of people with Type 2 diabetes. There are few studies of specific cardiac risks for people with Type 1 diabetes, especially for those with A1c’s in target range.

♥︎  I am extremely active and exercise daily. I have no pain or fatigue that might suggest CVD.

♥︎  I am a woman and heart disease affects more men than women.

Considering the HeartI could go on and on listing excuses for discounting my risk for heart disease. Instead I decided to do some research by starting with the Google search term “Type 1 diabetes and heart disease.”

I was surprised to find quite a few links. Some were relevant. Others were just the inclusion of Type 1 diabetes into “general” diabetes, really meaning Type 2. By far the most helpful document I found was a 2014 article titled “Type 1 Diabetes Mellitus and Cardiovascular Disease: A Scientific Statement from the American Heart Association and American Diabetes Association.” This statement was prepared by a committee of physicians chaired by Sarah D. de Ferranti, MD, MPH and is a thorough investigation into current knowledge and studies on the relationship of Type 1 diabetes and cardiovascular disease. The introduction to the statement begins:

Despite the known higher risk of cardiovascular disease (CVD) in individuals with type 1 diabetes mellitus (T1DM), the pathophysiology underlying the relationship between cardiovascular events, CVD risk factors, and T1DM is not well understood. Management approaches to CVD reduction have been extrapolated in large part from experience in type 2 diabetes mellitus (T2DM), despite the longer duration of disease in T1DM than in T2DM and the important differences in the underlying pathophysiology.”

This statement is long, but very readable. If you have Type 1 diabetes, you should definitely read it or at least bookmark it for future use. The full text of the article is available for free. There is no way that I can summarize the statement completely, but below I will share some things that I learned:

♥︎  Although I tend to think of the link of ‘heart disease” to Type 1 diabetes, I need to consider the whole CVD package of coronary heart disease (CHD), cerebrovascular disease including strokes, and peripheral artery disease (PAD).

♥︎  While admitting that more research is needed to understand the incremental risk and clinical presentation of CVD in people with T1DM, the authors state that “Overall, CVD events are more common and occur earlier in patients with T1DM than in nondiabetic populations.” Statistics mentioned are that the age-adjusted risk in Type 1 is about 10 times that of the general population and that CVD events occur on average 10-15 years earlier than for matched non-diabetic subjects. One analysis of 5 studies indicates that for each 1% increase in A1c, the risk for peripheral artery disease goes up by 18%.

♥︎  Although rates of CVD in the general population are lower for premenopausal women than for men, this female sex protection is not seen for women with Type 1 diabetes. At all ages women with T1DM are more likely to have a CVD event than healthy women.

♥︎  Atherosclerotic abnormalities can be seen in children and adolescents with T1DM.

♥︎  Autonomic neuropathy in T1DM can result in silent (asymptomatic) cardiac events with delayed diagnosis due to absence of pain and other vascular symptoms.

♥︎  The follow-up study to the Diabetes Control and Complications Trial (DCCT: 1983-1993) was the Epidemiology of Diabetes Interventions and Complications study (EDIC: 2005). EDIC reported that intensive therapy reduced the risk of cardiac events by 42%.

♥︎  The downside of improved glycemic control is that it can lead to weight gain and insulin resistance in people with Type 1. It is assumed that as A1c levels improve, the importance of general cardiac risk factors such as central obesity, high blood pressure, high LDL cholesterol, and high triglycerides gain increasing importance.

♥︎  Most research on the incremental risk and clinical presentation of CVD in people with diabetes is based on studies of people with Type 2 or no distinction is made as to type. However, the studies which are specific to Type 1 find increased risks for people with Type 1 when compared to healthy control subjects.

One other article of particular interest is from the August 2013 issue of Diabetes Forecast and is titled What’s Behind Heart Attacks in Type 1 Diabetes? This article highlights the research of Joslin Diabetes Center Investigator Myra Lipes, MD and outlines the idea that autoimmunity may be behind the increased rates of CVD for people with Type 1. Initial studies have suggested that an out-of-control autoimmune response post-heart attack is responsible for the fact that people with Type 1 diabetes are at high risk for poor outcomes after a heart attack.

Summary:  I have learned a lot about cardiovascular disease and Type 1 diabetes. Although more studies are needed to understand the specific CVD risks for people with Type 1 diabetes, there is definite proof that I should not continue to play the “Not Me” card. In my next post of this 3-part series on cardiovascular disease, I will share information on the particular risks that women have for heart disease.

Please remember that I am not a medical professional. Although this post presents a lot of information about cardiovascular disease and Type 1 diabetes, it is by no means complete. Do your homework and talk to your medical professionals about your risk. 

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***   Relevant Articles   ***

AHA/ADA Scientific Statement: Type 1 Diabetes Mellitus and Cardiovascular Disease: A Scientific Statement From the American Heart Association and American Diabetes Association

Type 1 Diabetes and Coronary Artery Disease, Diabetes Care, November, 2006

Type 1 diabetes and cardiovascular disease, Cardiovascular Diabetology 2013

What’s Behind Heart Attacks in Type 1 Diabetes?, Diabetes Forecast, August, 2013

Wayback Wednesday: All About Diabetes and Heart Health, Diabetes Mine

 

***  Related Posts  ***

Considering the Heart | Part 2 | Women with Type 1 Diabetes

Considering the Heart | Part 3 | My Story