How are metabolism and nutrition linked to COPD?
People with chronic obstructive pulmonary disease (COPD) often have problems that are linked to the body’s metabolism and nutrition. Metabolism is the group of chemical processes in the body that digest food and turn it into energy to power the body’s functions.
Conditions linked to nutrition and metabolism that COPD patients often have are:
- Metabolic syndrome
- Diabetes
- Having an unhealthy body weight
What is metabolic syndrome?1,2,3
Metabolic syndrome is the name for a group of symptoms called “metabolic risk factors”:
- A large waist, with excess fat around the stomach
- High level of triglycerides – a type of fat – in the blood
- Low HDL cholesterol level
- High blood pressure
- High blood sugar
A person who has at least three of these symptoms has metabolic syndrome. This means that the person has a high risk of having problems like heart disease, diabetes, and stroke.
People with COPD have a higher risk of developing metabolic syndrome than people without COPD. Younger COPD patients and patients at Stage I or II of the disease tend to have metabolic syndrome more often.
Cigarette smoking can cause both COPD and metabolic syndrome. Being overweight is a cause of metabolic syndrome, and people with COPD can be overweight because they are not able to be very physically active.
Treating metabolic syndrome is important because it lowers the risk of other serious medical problems for people with COPD.
What is diabetes?3,4
Diabetes is a condition where the amount of sugar (also called “glucose”) in the blood is too high. Many foods contain glucose. A substance called insulin is made by the body to process the glucose we eat. It turns the glucose into energy that can be used by the body.
The bodies of people with diabetes do not make enough insulin naturally. This means that too much glucose builds up in their blood. If it is not treated, diabetes can cause many other serious health problems.
People with COPD have a higher risk of developing diabetes, especially if they are overweight. Another reason that people with COPD are more likely to develop diabetes is due to a type of medicine called “steroids” that is used to treat the symptoms of COPD.
Taking steroids can make a person have a slightly higher risk of getting diabetes.
However, that risk is more strongly linked to steroids that are taken orally, in a tablet or pill. Also, the side effects linked to steroids taken orally are higher if:
- The steroid is taken in high doses
- The steroid is taken in smaller doses over a longer period of time
COPD patients tend to use inhaled steroids, which carry a lower risk of side effects. When COPD patients take oral steroids, it is more often on a short-term basis to help treat a COPD flare-up. This also carries a lower risk of side effects, such as diabetes.
Sometimes changes in diet and lifestyle can treat diabetes. In other cases, diabetes is treated with different types of medicine to make sure that the amount of glucose in the blood is not too high.
How is having an unhealthy body weight linked to COPD?4
Many people with COPD have problems keeping a healthy body weight:
- Some people gain weight
- Some people have trouble keeping weight on
Healthcare providers use a measurement called the body mass index (called “BMI” for short) to find out if a person is a healthy weight. The BMI compares a person’s height and weight to calculate a number:
- BMI less than 18.5 = underweight
- BMI between 18.5 - 24.9 = healthy weight
- BMI between 25 – 29.9 = overweight
- BMI more than 30 = obese
People with COPD often have BMIs showing that they are overweight or obese. One reason for this is that taking steroids to treat COPD symptoms can cause a person to gain weight. Another reason is that many people with COPD are not able to be very physically active or to exercise, which can lead to gaining weight. People with Stage I or Stage II COPD are more likely to be overweight than people with later stages of COPD.
It is important for COPD patients to have a healthy body weight, because being overweight can make COPD symptoms worse. Carrying more weight is more work for the body and for the lungs. Not being active enough can make a person feel even more breathless and tired. COPD patients should eat a healthy diet and exercise regularly to maintain a healthy body weight.
Being underweight is also a problem for many COPD patients. This usually affects people in the later stages of the disease. With COPD, a person needs to use a larger amount of energy just to breathe. Eating can make the person feel even more out of breath or trigger coughing. Because of this, some patients do not eat enough nutritional calories to maintain a healthy weight and provide their body with enough energy to function.
Healthcare providers often advise COPD patients who are underweight to consume as many calories as they can. Protein drinks can help with this when chewing and eating solid food takes too much energy and breath. Smaller, more frequent meals can also be helpful. This can help them gain weight. In some cases, medicines may also be prescribed to increase appetite.