While not all people with COPD have diabetes, some do. In fact, studies seem to show that just under 20% of people with COPD also have diabetes. Here’s all you need to know about links between COPD and diabetes. (1)
So, what is diabetes?
Those of you who have diabetes probably know more than I ever will about this disease. So, you can just skip to my next question. For the rest of us, here’s a quick summary of diabetes. It begins with…
Glucose. It’s is a simple sugar, and is a source of energy used by cells of your body. It comes from carbohydrates in the foods you eat, such as fruits, breads, rice, potatoes, oatmeal, vegetables, dairy, etc. As these foods are metabolized (broken down) by your digestive system, glucose is the byproduct. It is released into your bloodstream where it is referred to as blood glucose or blood sugar. Under normal conditions, your pancreas measures the amount of glucose in your blood. If it is too high it secretes Insulin. If it is too low it secretes glucagon. (1)
Insulin. Glucose cannot enter cells on its own. So, when the pancreas recognizes glucose levels are rising (like when you’re eating), it secretes Insulin. It’s a protein secreted from beta cells in the pancreas that bind with receptors on cells of muscle tissue, skeletal muscle tissue, and fat tissue telling them to take in glucose from the bloodstream. These cells then use this glucose as energy to do whatever that cell’s job is. Insulin also signals your liver to absorb Insulin and convert it to glycogen which is stored in the liver and muscles. Glycogen acts as an “energy reserve” between meals. (1, 3-4)
Glucagon. Say it’s been awhile since you’ve eaten. In this case, glucose levels start to decline. Your pancreas recognizes this and secretes glucagon from alpha cells. Glucagon is a protein that tells the liver to break glycogen down into glucose, which is released into your bloodstream to increase your blood glucose levels. (1, 3-5)
Diabetes. More precisely called diabetes mellitus. Certain abnormalities cause blood glucose levels to get too high, a condition called hyperglycemia. There are 2 types.
- Type 1 Diabetes. It’s an autoimmune disease where your own immune system attacks beta cells that make Insulin in your pancreas. Your pancreas, therefore, does not secrete enough insulin. It’s usually diagnosed in young adults and children. It requires injectable Insulin, and so it’s often called Insulin Dependent Diabetes. (6)
- Type 2 Diabetes. Your pancreas makes insulin, but your body is unable to use it. This is referred to as insulin resistance. Beta cells in your pancreas respond by secreting more Insulin. When they can no longer keep up, they stop producing Insulin. It’s usually diagnosed in overweight adults. It can be treated with exercise and diet, although sometimes Insulin is required. (6-7)
What are links between diabetes and COPD?
About 10.5% of the general population has a diagnosis of diabetes. However, about 18.7% of the COPD population has a diagnosis of diabetes. Researchers are not sure whether diabetes causes COPD or whether COPD causes diabetes. It may be possible that both are true. (8)
Diabetes. Researchers are not sure why people develop diabetes. They are also unsure of how diabetes might cause COPD. However, some studies do show that people with diabetes had some loss of lung function resulting in a diagnosis of either asthma or COPD. Some studies point to the hyperglycemia itself, while others point to Insulin treatment. So, further studies are needed to understand how diabetes might cause COPD.
COPD. Other studies seem to show that COPD might cause diabetes.There are a variety of theories here.
- Mediators of Inflammation. One theory is that the same inflammatory chemicals responsible for airway changes (chemokines, cytokines) in COPD may also get into your blood system and cause damage to other systems, including the pancreas or liver.
- Oxidative Stress. Another theory is that some of the 5,000 plus chemicals in cigarette smoke may cause an increase in free radicals and a decrease in antioxidants, thereby causing oxidative stress. This damages airways causing COPD, but it may also occur in the pancreas causing diabetes.
- Hypoxia. As COPD advances, it can cause a drop in oxygen levels. When tissues of your body don’t receive enough oxygen, it’s called hypoxia. The exact mechanisms of how this might cause diabetes remains a mystery, but this is just one theory.
- Systemic Corticosteroids. More than 70% of people diagnosed with COPD will require systemic corticosteroids at some point. These are often needed to overcome COPD flare-ups. However, it is well known that corticosteroids can increase blood glucose levels and cause type 2 diabetes. Among the COPD population, taking systemic corticosteroids increases the risk of developing diabetes by 34%. This is why some people diagnosed with COPD may require regular glucose checks. Usually, when this treatment is stopped, glucose levels return to normal. (8-9)
What to make of this?
Again, not all people diagnosed with COPD will be diagnosed with diabetes. However, it does seem to affect enough of those living with this disease to generate concerns and to inspire further research in this area. Further research in this area should lead to better wisdom to allow people diagnosed with COPD live better and longer.