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New research shows that breathlessness in middle-aged adults is more common in women and is associated with overweight/obesity, respiratory disease, stress, and depression, cardiac disease, and anemia.

“These findings inform on key factors to consider in the clinical evaluation of people with breathlessness and support the importance of lifestyle interventions to prevent and reduce the burden of breathlessness across the population,” wrote researchers in the journal Respiratory Research.

According to the investigators, activity-related breathlessness impacts 10% to 25% of middle-aged and older individuals in the general population and “knowledge is limited on the contribution of medical conditions to the burden of breathlessness in the population,” they wrote.

To fill this gap in knowledge, investigators conducted a population-based, cross-sectional analysis of the Swedish CArdioPulmonary bioImage Study (SCAPIS), which enrolled individuals aged 50 to 64 years from 2013 to 2018 at 6 study centers. They also evaluated breathlessness in clinically relevant subgroups by sex, smoking history, and presence or absence of self-reported cardiorespiratory disease.

For the purpose of the study, breathlessness was defined as a self-rated modified Medical Research Council (mMRC) score of at least 2 and was evaluated in relation to various self-reported medical conditions (reported by patients as being physician diagnosed). The analysis also included self-reported data on demographics, smoking history, pack-years of smoking, education, type of residence, stress, depression, and exercise level.

The analysis also included patient data regarding body mass index (BMI), postbronchodilator spirometry forced expiratory volume in 1 second, forced vital capacity, pulmonary emphysema, chronic airflow limitation, coronary artery calcifications, and coronary artery stenosis. Population attributable fractions (PAFs) were calculated based on the prevalence of each condition and its adjusted odds ratio (aOR).

The analysis included 25 948 individuals, with a mean age of 57.5 years and mean BMI of 26.9 kg/m². Among the cohort, 51% were women, 37% were former smokers, 12% were current smokers, 43% were overweight, 21% were obese. Also, among the cohort, 25% had respiratory disease, 14% had depression, 9% had cardiac disease, and 3% had anemia.

FINDINGS

Results showed that breathlessness (mMRC ≥2) was present in 3.7% (n=952) of participants. Compared with individuals without breathlessness, those with breathlessness were more frequently women and had increased rates of previous or current smoking, obesity, lung function impairment, and lower socioeconomic status.

Individuals with breathlessness compared to those without breathlessness had an increased prevalence of obesity (56% vs 19%), respiratory disease (49% vs 24%), stress (41% vs 20% reporting constant stress for 1 year or longer), depression (37% vs 13%), cardiac disease (19% vs 9%), and anemia (5% vs 3%) (P < .001 for all comparisons), according to investigators.

Medical conditions with the highest PAFs for breathlessness were overweight and obesity (62.9%; 95% CI 59.6%-66.0%), stress (60.2%; 95% CI 31.6%-76.8%), respiratory disease (29.1%; 95% CI 20.1%-37.1%), depression (22%; 95% CI 17.1%-26.6%), cardiac disease (9.5%; 95% CI 6.3%-12.7%), and anemia (2.0%; 95% CI 0.8%-3.3%).

Investigators observed that women had a higher prevalence of breathlessness (5% vs 2%), lower BMI, more stress, depression, and anemia but less cardiac disease, compared with men. Breathlessness occurred in 5.7% of those who currently smoked, 4.3% of those who formerly smoked, and 2.7% of those who never smoked.

“This study provides novel data on the most common underlying medical conditions to consider in the clinical evaluation of people with breathlessness, and given the population-based design, the findings may pertain particularly to people evaluated in primary care,” noted study authors.

Limitations of the current study include the absence of physiologic assessments such as cardiac ultrasound for heart failure and no evaluation of the effects of aerobic fitness. Also, breathlessness was measured with the mMRC scale, which is likely to underestimate the presence and burden of breathlessness.

“Further research is needed on the impact of medical conditions in younger and older age groups and on the broader interplay between physiological, psychological, social, and environmental factors on breathlessness, including from longitudinal studies,” concluded researchers.

Source: Ekström M, Sundh J, Andersson A, et al. Exertional breathlessness related to medical conditions in middle-aged people: the population-based SCAPIS study of more than 25,000 men and women. Respir Res. 2024;25:127. doi:10.1186/s12931-024-02766-6