Common Comorbidities of COPD
Patients with COPD typically have multiple comorbidities, many that share risk factors. In particular, smoking cigarettes and obesity are well-documented causes of inflammation. Systemic inflammation — the activity of immune-related cells in the body that promote inflammation — increases risk for COPD as well as a variety of other chronic conditions, such as cardiovascular or metabolic conditions. Having COPD can increase risk for developing a comorbid condition or vice versa. In addition, COPD comorbidities may exist because COPD and common comorbid conditions frequently occur in older age. Common comorbidities of COPD include:
Various forms of cardiovascular disease, including hypertension, coronary artery disease, and heart failure, are the most common and most notable COPD comorbidities, because they have a significant impact on mortality. One systematic review found that patients with COPD had 2.5 times higher odds of developing any form of cardiovascular disease, including ischemic heart disease, cardiac dysrhythmia, heart failure, and arterial diseases like hypertension.
Diabetes and Metabolic Syndrome
The prevalence of diabetes among COPD patients ranges from 10% to 19%; the prevalence of metabolic syndrome among COPD patients has been estimated to be between 20% and 50%, depending on COPD severity. Research on COPD and type 2 diabetes suggests that systemic inflammation may increase the risk for or impact the trajectory of each condition. Lung inflammation is the hallmark of COPD; systemic inflammation, in part driven by obesity, can reduce insulin resistance and increase risk for type 2 diabetes. In addition, the use of inhaled steroids – a common medication for COPD treatment – increases risk for the development of diabetes and influences disease progression.
Osteoporosis results in reduced bone density and increased risk for bone fractures. Smoking and systemic inflammation increase risk for both COPD and osteoporosis; some research suggests that steroid use may also be a risk factor for osteoporosis. Fractures due to falls among older adults are more severe among individuals with osteoporosis, and functional impairment and physical limitations resulting from COPD can increase that risk. Declining health status due to older age increases risk for both osteoporosis and COPD.
Individuals with low lung function are 2 to 4 times more likely to have lung cancer compared to those with normal lung function. Exposure to respiratory irritants, such as cigarette smoke or environmental pollutants, are risk factors for both conditions. Symptoms of COPD, such as obstructed airflow, respiratory exacerbations in the past year, and visual emphysema, have been shown to increase the odds of developing lung cancer.
Mood disorders, particularly depression, are common among individuals with COPD. The prevalence of depression among individuals with COPD is estimated to range from 20% to 60%, depending on COPD severity and screening techniques. Most research suggests that mood disorders may result from or be amplified by COPD. Functional impairment resulting from depression can reduce a COPD patient's ability to socialize, which may increase isolation. COPD and various comorbidities may also cause an individual distress that could contribute to depression, such as declining health status, reduced quality of life, or overwhelming financial burdens. In addition, age can influence the relationship between depression and COPD. Older adults are more likely to experience social isolation, which has negative mental health impacts, and are more likely to have COPD due to declining health status and the cumulative impact of smoking and other respiratory irritants.
Approximately 10% of COPD patients have obstructive sleep apnea and about 20% of people with sleep apnea are also diagnosed with COPD. Overlap of the two conditions can result in even lower oxygen levels in the blood while an individual sleeps, but it is still unclear whether the two respiratory conditions lead to worse health impacts compared to each condition separately. In general, patients with COPD often report greater sleep disturbances than individuals without COPD, including interrupted sleep and less deep sleep.
Since patients may manage a large quantity of pharmacologic treatments for multiple conditions, medication reconciliation is a critical component of COPD management. Patients should take the correct medications at the appropriate dosages and frequencies. For example, it is important that patients stop taking certain medications when directed or that they not accidentally take someone else's medication. In addition, some medications may produce adverse effects when combined, so it is important that healthcare providers keep an accurate and updated record of a patient's prescription medications to avoid medication-related complications.