Obesity and COPD

Obesity and chronic obstructive pulmonary disease (COPD) are linked with each other in several ways. Breathing difficulties characteristic of COPD can make it hard to maintain a healthy weight, and excess weight can exacerbate COPD symptoms. Both can also lead to heart disease, the risk of which may be compounded if you have both conditions.

But the relationship between the two conditions is complex. Being very underweight is associated with a higher risk of COPD-associated mortality, so weight also seems to have a protective effect in some cases.

Shared Health Effects

COPD and obesity are both serious medical conditions that lead to slowly declining health.

The breathing difficulties that come with COPD can reduce your body's oxygen supply, causing fatigue. Related exercise intolerance (shortness of breath caused by physical activity) can lead to a sedentary lifestyle, a risk of which is obesity. In the long term, COPD leads to heart failure.

Obesity affects lung function in many ways as well, and the impact is worse if you have COPD. Excess weight increases the work of breathing, which is already impaired in COPD. The additive effects can make it a struggle to breathe and cause dyspnea (shortness of breath). Fatigue that can occur from carrying excess weight only heightens the challenges of daily activities.

Obesity also increases the risk of pulmonary disease, stroke, heart attack, and dementia.

Nighttime Breathing

Obesity is linked to sleep apnea, a condition characterized by periods of interrupted breathing during sleep. COPD is a major risk factor for transient nocturnal desaturation, which is characterized by low blood oxygen levels during sleep.

While sleep apnea and transient nocturnal desaturation are different problems, they have the same consequences: low energy and impaired health due to decreased blood oxygen levels. The additive effects of obesity and COPD can worsen daytime symptoms and lead to more severe health consequences resulting from low nighttime oxygenation.

Diagnostic Testing

Obesity is usually diagnosed using body mass index (BMI), which is a flawed but commonly used measure of the relationship between weight and height.

You can use a BMI chart to know if you are overweight or obese:

• Underweight: <18.5
• Normal: 18.5 to 24.9
• Overweight: 25 to 29.9
• Obese: >30.0

The BMI chart isn't perfect, as it doesn't take into account factors like body type and build, but it is a good place to start. You may wish to talk to your healthcare provider, who can consider some of these other variables and give you an estimate of your ideal weight.

Pulmonary Tests

The severity of your COPD can be assessed with imaging tests (such as chest X-ray or computed tomography, CT). Pulmonary function tests (PFTs) are used to evaluate lung function in COPD.

Common PFTs include:

• Forced expiratory volume in one second (FEV1)
• Forced vital capacity (FVC)
• Total lung capacity (TLC)

Treatment

If you are overweight or obese with COPD, weight loss is an important aspect of treatment. Safe and effective weight loss generally requires a combination of diet and physical activity.

Exercise and Pulmonary Rehabilitation

Exercise is encouraged in COPD, but you should start with a medically-guided exercise regimen that is created for you. A pulmonary therapist can work with you to improve your exercise tolerance.

Incorporating pulmonary rehabilitation into your COPD treatment and weight loss plan can improve your respiratory abilities during exercise—as well as at rest, and possibly at night too.

Diet

Your healthcare provider may advise you about factors you need to consider in addition to the need to lose weight when designing your eating plan. For example, if you are low in a nutrient such as calcium or vitamin B12, you will need to incorporate foods rich in these nutrients when planning your diet.

Diabetes can be a complicating factor as well because it requires you to carefully plan your meals to optimize your glucose intake. And if your cholesterol or triglyceride levels are high, you may need to maintain a diet that helps you decrease these levels while you lose weight.

A Word From Verywell

Obesity and COPD are common, but there are nuances to the relationship between the two diseases. If you are obese with COPD, a healthy approach to weight loss can help. Keep in mind that you may lose weight if your COPD worsens. Working with your medical team to put some weight on may help prevent serious consequences of your COPD.