In a study published in ACR Open Rheumatology,1 investigators explored the connection between patients with systemic lupus erythematosus (SLE) and an increased risk of asthma and chronic obstructive pulmonary disease (COPD), which concurrently correlated with worse patient-reported outcomes (PROs) cross-sectionally.
Over the course of 3 years, investigators used 2 US-based SLE cohorts, FORWARD (The National Databank for Rheumatic Diseases in Wichita, Kansas) and the University of California San Francisco’s Lupus Outcomes Study (LOS), to examine prevalence, incidence, and impact of asthma and COPD for patients with SLE. They defined prevalence as the presence of the conditions at the onset of the study and incidence as any new reports over the 3 years. In the FORWARD group, participants received questionnaires every 6 months, while the LOS group collected data from annual telephone interviews. Both groups provided sociodemographic and health status details, which included smoking history. The PRO section asked about pain, sleep, health ratings, any depressive symptoms, lupus activity, and flare.
The mean age for the FORWARD group was 50.5 years and participants were 87.2% white non-Hispanic with a mean SLE duration of 15.8 years and 36.1% obesity. The LOS participants had a mean age of 46.7 years, 68.5% were white non-Hispanic, they had an SLE duration of 12.6 years, and 25.7% obesity. More than 90% of both cohorts were female and 40% had a history of smoking.
In the FORWARD cohort, both patients with asthma at baseline and those who developed it within the 3-year period were more frequently female, had obesity, and higher SLE activity ratings. Both patients with COPD at baseline or those who developed COPD tended to be older, obese, had lower incomes, a history of smoking, and had active lupus with a longer duration. In the LOS cohort, participants with asthma or COPD at baseline or those who developed it within the study period were generally older, had a history of smoking and obesity, had lower incomes and education, and rated their lupus as more active.
The Rheumatic Disease Comorbidity Index (RDCI) reported comorbid conditions including cardiovascular conditions, stroke, hypertension, depression, diabetes, cancer, ulcer, and fracture in the FORWARD cohort. LOS summarized conditions such as hypertension, heart disease, myocardial infarction, stroke, cancer, ulcer, and back problems.
A longitudinal analysis was created to compare preexisting asthma and COPD with the individual’s last observation at the end of the 3-year study. Two models were created, adjusting for baseline age, sex, race, disease duration, education, income, obesity, history of smoking, comorbidities, and lupus manifestations. The second model added the baseline value of the dependent variable (PRO) to account for any changes.
At the start, the LOS cohort reported 36% of patients with either asthma or COPD and the FORWARD group had 19.8% (487/2457) with asthma and 8.3% (179/2149) with COPD. During the course of 3 years, 87 reported asthma (4.4%) and 101 reported COPD (4.2%). The national average of adult females with asthma is 9.7% and COPD is 6.1%.
Analysis showed that asthma and COPD were associated with greater self-reported SLE activity and worse lupus-specific and generic PROs, even after adjusting for sociodemographic and health factors, including smoking. “A clear pattern of worse status on PROs was noted when comparing individuals with asthma or COPD and those without in both cohorts…Self‐reported SLE disease activity was also greater in those with these comorbidities,” stated investigators. “Symptoms from asthma and COPD may lead patients to perceive worsening in their SLE that would not be recognized in clinical assessments of SLE activity, potentially leading to discordance in patient and provider assessments.”
This study was limited by the possibility that self-reporting may lead to inaccuracies, including under-responding. Additionally, current smokers and those with low education are less likely to follow up, which can lead to underestimation. However, strengths of the study include the large size of the cohort and a variety of PROs.
“We found evidence of increased prevalence of asthma and COPD in these cohorts of individuals with SLE. We also found that the presence of these conditions was associated with worse status on physical function, fatigue, perceived cognitive function, and pain, all of which are important PROs in SLE, in both cohorts,” explain investigators. “These findings suggest that health care providers should routinely screen individuals with SLE for asthma and COPD and ensure that they are receiving adequate treatment for those conditions. In addition, counseling for smoking cessation and screening for occupational exposures that are linked to the development of pulmonary conditions is also advisable. Future analyses of PROs in SLE should also include asthma and COPD as important comorbid conditions.”
Katz P, Pedro S, Trupin L, Yelin E, Michaud K. The Impact of Asthma and Chronic Obstructive Pulmonary Disease (COPD) on Patient-Reported Outcomes in Systemic Lupus Erythematosus (SLE) [published online ahead of print, 2021 Feb 20]. ACR Open Rheumatol. 2021;10.1002/acr2.11212. doi:10.1002/acr2.11212