Can what you eat affect your disease?
Editor's note: In this article, Anna Hemnes, MD, provides an overview of her 2013 webinar from PHA Classroom, “Can What You Eat Affect Your Disease State?” She highlights the metabolic role of diabetes, nutrition and exercise in PH.
Research into pulmonary hypertension in the past decade has highlighted a potential role for metabolism in some forms of PH. In particular, how the body handles sugar (glucose) and fat (lipid) may be different in and potentially even worsen some forms of pulmonary hypertension.
PH, Sugars and Fats
Pulmonary arterial hypertension and pulmonary venous hypertension, often from left heart failure or diastolic dysfunction, are closely tied to insulin resistance, pre-diabetes and/or diabetes mellitus, which are problems in which the body’s ability to move sugars into cells is impaired and blood glucose may be elevated. Often these conditions are found with obesity as well. Exactly what causes these metabolic problems and how these fat and glucose abnormalities might affect the lung’s blood vessels is an active area of research and is not well understood yet. Importantly, although it has not been shown that treating glucose disorders like insulin resistance and diabetes mellitus improve PH, it is well known that treating glucose disorders like diabetes reduces cardiovascular death, kidney disease and other problems that are complications of elevated glucose in the blood.
So, what should we do with this information?
Because sugar and fat disorders are common in PH, it is a good idea to discuss these problems with your healthcare provider. Sometimes a simple fasting blood test will be required to diagnose elevated blood sugar or blood lipid levels. If you already know you have a sugar or fat metabolism problem, you may be following a special diet, such as a low-carbohydrate or low-cholesterol diet. Occasionally these are called a “heart-healthy diet.” Or you may be taking medications for these conditions. If so, continuing on your diet or medication program and close follow up with your doctor is appropriate.
If you have diabetes, pre-diabetes or elevated cholesterol or other blood lipid conditions and you are not being treated, you can discuss if therapy is needed with your healthcare provider. Generally primary care physicians treat these conditions, or your PH provider might help you with them. Because there are known complications for all patients with diabetes mellitus and elevated cholesterol regardless of whether patients also have PH, it is important to be treated to reduce those complications, even if doing so may not improve your PH. If you do not have any problems with diabetes or elevated lipids, it is often still a good idea to follow a heart-healthy diet to maintain a healthy weight. There are lots of resources on following a healthy diet, but some can be found on PHA's website and also on the American Heart Association’s website.
Can exercise help?
Many patients are curious about exercise and whether it is beneficial for PH patients. There are times when patients cannot exercise, for instance those who pass out when they do minimal exercise such as walking around or up stairs. However, many patients can do some form of exercise such as walking, water aerobics or stationary bike riding. It is important to discuss if this is appropriate with your PH physician before starting an exercise program. Some data indicate that exercise may improve PH symptoms in patients who can tolerate it, so it is a great way to control weight, improve strength and possibly improve your endurance in every day activities. Exercise can also help with controlling elevated blood sugar, which may help diabetes mellitus and insulin resistance. Generally, we recommend light aerobic activities like walking, but recommend staying away from lifting more than 10-15 lbs., which may put too much stress on the heart.
Bringing It All Together
To summarize, we are learning more about how metabolic problems like elevated blood sugar and fats affect pulmonary hypertension, but don’t know yet if treating these conditions will improve pulmonary hypertension. While we learn the answers to these questions in the coming years, it is a good idea to control elevated blood sugar if you have diabetes mellitus, high cholesterol or other lipids and to maintain a healthy weight. You can work with your health care provider to achieve these goals and to discuss if exercise might be appropriate for you.
By Anna Hemnes, MD, Assistant Director, Pulmonary Vascular Center, Vanderbilt University Medical Center, Nashville, Tenn.
Enjoy Dr. Hemnes’s entire webinar on this topic. PHA Classroom regularly hosts live e-learning events like Dr. Hemnes's talk for patients, family members and friends. Recordings are then posted on PHA Classroom for future viewing. Visit the PHA Classroom to learn more.
This article orginally appeared in the Fall 2014 issue of Pathlight.