Asthma, A Risk Factor U-Turn?

With falling mortality from effective medical management, asthma is mostly not a major underwriting consideration for Life insurers. However, asthma is currently in the headlines again as a possible risk factor for more severe forms of Covid. Dr. Achim Regenauer clarifies the situation in this interview, updating us on the latest trends and research, including on how asthma and the SARS-CoV-2 virus interact.

Can you start by telling us how asthma prevalence is trending and why?

This depends largely on the definition of asthma, geographical region and age group. In European, North American and some Asian countries, there appears to be an upward trend. For example, research based mainly on repeat studies of school age children¹ shows that asthma prevalence in most western countries increased over the last four decades of the 20th century.

The reason for this upward trend is a shift in the underlying cause/trigger or in factors that exacerbate the disease. Most notably, anthropogenic climate change has increased pollen concentrations and extended pollen seasons. Airborne pollen has a higher negative impact on bronchial reagibility than air pollution.

And is asthma mortality also increasing?

Fortunately, the mortality of asthma patients has been decreasing over the last few decades.² The most plausible explanation for this is the early use of corticosteroids, mostly via inhalators, combined with better compliance and lower rates of smoking. However, the mortality of asthma patients is still higher than that of non-asthmatics.

In fact, aside from severe asthma episodes/exacerbations, much remains unknown about the link between asthma and causes of death. One cross-sectional, multi-center study found that the most common causes of death amongst asthma patients are cardiovascular diseases, followed by malignancies and infections.³ Asthma patients who are additionally suffering from chronic obstructive pulmonary disease (COPD), a condition known as asthma–COPD overlap syndrome (ACOS), have higher mortality than asthma-only patients.⁴

We’ve seen the headlines connecting asthma with Covid. Does the latest research fully support a connection between pre-existing asthma and an increased risk of SARS CoV-2 infection or of developing a more severe form of Covid?

For the majority of patients, asthma does not appear to be a strong risk factor for acquiring a SARS-CoV-2 infection or to increase the risk of more severe Covid. One major review, for example, found no difference in the duration of hospitalization or the risk of intensive care unit (ICU) transfer between asthmatic and non-asthmatic patients.⁵

In fact, counter-intuitively, there are even several studies that indicate that asthma could be linked even to a reduced risk of Covid mortality.⁶

So far, studies have not identified any “dangerous liaisons” between asthma and Covid. However, further clinical studies will be necessary to confirm these surprising preliminary findings. The situation may therefore change and needs closely watching.

What about a connection to long Covid? Do any studies show that pre-existing asthma increases the risk of developing this post-viral condition?

Yes. Here there appears to be a connection. Consistent, demographic long Covid risk factors from across many studies include pre-existing asthma, as well as increasing age, female sex, overweight/obesity and (pre-pandemic) poor physical and mental health.

So rather than being a borderline impairment for most Life underwriters, there are several aspects of asthma that underwriters should be aware of?

Yes. The mortality of asthma patients, especially those with more severe asthma and ACOS, remains higher than non-asthma patients. The indication is that asthma patients have a more rapid decline in lung function compared to those without asthma.⁷ Studies have also identified a connection between the rate of decline in lung function and the severity of asthma symptoms. In addition, longitudinal studies have shown that asthma in early childhood results in decrements in pulmonary function that are persistent and detectable throughout childhood and adolescence, and even through adulthood. Asthma is also a risk factor for long Covid. The submission of a lung function test for Life applicants, other than for those with only mild asthma, is therefore helpful for underwriting.

Contributor

Achim Regenauer, Chief Medical Officer, Europe and Asia Pacific

Opinions expressed are solely those of the author. This article is for general information, education and discussion purposes only. It does not constitute legal or professional advice and does not necessarily reflect, in whole or in part, any corporate position, opinion or view of PartnerRe or its affiliates.

References

1 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC557212/; https://academic.oup.com/jpubhealth/article/38/3/e263/2239842?login=false

2 https://www.resmedjournal.com/article/S0954-6111(18)30242-7/fulltext

3 https://bmcpulmmed.biomedcentral.com/articles/10.1186/1471-2466-13-73

4 https://www.dovepress.com/incidence-and-long-term-outcome-of-severe-asthmandashcopd-overlap-comp-peer-reviewed-fulltext-article-COPD

5 https://www.karger.com/Article/FullText/510953

6 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401144/pdf/main.pdf

7 https://erj.ersjournals.com/content/30/3/411