Increasing Rates of Obesity Contribute to Breathlessness Symptoms

A recent Australian study, published in Respirology, aimed to determine the extent that obesity contributes to breathlessness, finding that around a quarter of breathlessness symptoms in adults could be contributed to obesity.

Increasing rates of obesity are a global health policy concern, the authors noted, with 603.7 million adults estimated to be obese in 2015. Despite one of the consequences of obesity being breathlessness, the magnitude of breathlessness symptoms associated with obesity had yet to be evaluated.

“Obesity is an important, modifiable cause of this prevalent [breathlessness] symptom, and our findings have implications for future health policy and clinical practice,” the authors of the cross-sectional study wrote.

The data from this study came from the National Breathlessness Survey in 2019, which was completed by a total of 10,072 Australian residents 18 years and older. Breathlessness was assessed using a scale ranging from 0 (“I only get breathless with strenuous exercise”) to 4 (“I am too breathless to leave the house”). Clinically important breathlessness was defined as having a score 2 (“I walk slower than people of the same age on the level because of breathlessness or have to stop for breath when walking at my own pace on the level”) or higher. Body mass index (BMI) was also reported, with obesity defined as a BMI greater than 30 kg/m2.

Participants were asked if they had ever been told by a doctor or a nurse that they had any of 32 medical conditions, including asthma, chronic obstructive pulmonary disease, back pain, arthritis, and ischemic heart disease. The participants were also asked to self-report mental health conditions using the Patient Health Questionnaire-4, with scores ranging from 0 to 12; a score of 6 or greater indicated moderate anxiety/depression symptoms and psychological distress.

Of the total participants, 305 were excluded due to clinically implausible values of BMI. Of the remaining 9769 participants, 51.4% were female, and 28.1% were obese. The prevalence of breathlessness was 9.54% (95% CI, 1.72-2.20).

Additionally, the adjusted relative risk (aRR) of obesity for breathlessness was 2.04 when adjusted for age. When adjusting for comorbid conditions, the aRR was slightly attenuated to about 1.85 to 1.98. The population attributable fraction (PAF), defined as the fraction of all cases of breathlessness that were attributable to obesity, ranged from 21.1% to 23.6% once adjusted for the presence of comorbid conditions.

Furthermore, the study found that women had higher proportions of breathlessness symptoms accounted for by obesity than men had.

The researchers acknowledged certain limitations to this study, which include the potential for variances in the relationship between breathlessness and obesity across different ethnic groups and different countries. Additionally, the relationship between obesity and breathlessness may be bidirectional, in which breathlessness may have induced obesity.

Overall, they noted, this study provides insight into a rising global health policy concern regarding breathlessness symptoms that the researchers expect will continue to increase globally.

Furthermore, the researchers suggested that increasing rates of obesity may negatively impact global workforce productivity as a result of breathlessness symptoms. However, they noted that clinicians should not assume breathlessness is always caused by obesity, and patients with obesity who report breathlessness should be evaluated for other medical causes. The authors also noted that obesity could be a potentially modifiable cause of breathlessness, so weight loss may improve breathlessness symptoms, as public health efforts aim to reverse global trends of increasing obesity prevalence.

“Our findings therefore suggest that the attribution of obesity to breathlessness could have almost doubled in 10 years,” the researchers wrote. “If this trend continues, and the aRR remains constant, a higher percentage of people in Australia will suffer from breathlessness related to obesity in the foreseeable future.”

Reference

Guo YL, Ampon MR, Poulos LM, et al. Contribution of obesity to breathlessness in a large nationally representative sample of Australian adults. Respirology. Published online November 6, 2022. doi:10.1111/resp.14400