Effect of the COVID-19 Lockdown on Asthma Biological Rhythms

Modifiable risk factors for asthma exacerbations during the COVID-19 pandemic: a population-based repeated cross-sectional study using the Research and Surveillance Centre primary care database

Background

There were substantial reductions in asthma exacerbations during the COVID-19 pandemic for reasons that remain poorly understood. We investigated changes in modifiable risk factors which might help explain the reductions in asthma exacerbations.

Methods

Multilevel generalised linear mixed models were fitted to examine changes in modifiable risk factors for asthma exacerbations during 2020-2022, compared to pre-pandemic year (2019), using observational, routine data from general practices in the Oxford-Royal College of General Practitioners Research and Surveillance Centre. Asthma exacerbations were defined as any of GP recorded: asthma exacerbations, prescriptions of prednisolone, accident and emergency department attendance or hospitalisation for asthma. Modifiable risk factors of interest were ownership of asthma self-management plan, asthma annual review, inhaled-corticosteroid (ICS) prescriptions, influenza vaccinations and respiratory-tract-infections (RTI).

Findings

Compared with 2019 (n = 550,995), in 2020 (n = 565,956) and 2022 (n = 562,167) (p < 0.05): asthma exacerbations declined from 67.1% to 51.9% and 61.1%, the proportion of people who had: asthma exacerbations reduced from 20.4% to 15.1% and 18.5%, asthma self-management plans increased from 28.6% to 37.7% and 55.9%; ICS prescriptions increased from 69.9% to 72.0% and 71.1%; influenza vaccinations increased from 14.2% to 25.4% and 55.3%; current smoking declined from 15.0% to 14.5% and 14.7%; lower-RTI declined from 10.5% to 5.3% and 8.1%; upper-RTI reduced from 10.7% to 5.8% and 7.6%. There was cluster effect of GP practices on asthma exacerbations (p = 0.001). People with asthma were more likely (p < 0.05) to have exacerbations if they had LRTI (seven times(x)), had URTI and ILI (both twice), were current smokers (1.4x), PPV vaccinated (1.3x), seasonal flu vaccinated (1.01x), took ICS (1.3x), had asthma reviews (1.09x). People with asthma were less likely to have exacerbations if they had self-management plan (7%), and were partially (4%) than fully COVID-19 vaccinated.

Interpretation

We have identified changes in modifiable risk factors for asthma exacerbation that need to be maintained in the post-pandemic era.

Funding

Asthma UK Centre for Applied Research and Health Data Research UK.

Dysregulation of mood, energy, and social rhythms syndrome (DYMERS): A working hypothesis

A syndrome centered on the dysregulation of behavioral rhythms (DBR) is discussed. Recent pandemic brought to observe: (1) Having a DBR affecting sleep patterns, eating habits, and social interactions, before the lockdown period, was a determinant for depressive episodes during the lockdown; (2) In tighter lockdowns, DBR triggered depressive episodes in bipolar patients; (3) DBR in healthcare workers under pressure was a determinant of burnout; (4) DBR influenced the course of chronic diseases by altering immune responses. In addition, it was found that scoring positive on the Mood Disorder Questionnaire (MDQ) was closely associated with the dysregulation of sleep rhythms. MDQ is a screening tool for bipolar disorder (BD), criticized for detecting too many false positives. Studies showed that positivity to the MDQ implied a severe impairment of quality of life even in people without psychiatric diagnoses. According to this evidence, three different hyperactivation levels could be proposed (from normality to pathology): firstly, an adaptive increase in energy (e.g. athletes performing well); secondly, a DBR determined from the continuous stimulation of stress hormones, with possible positive scores on the MDQ without a diagnosis of bipolar disorder, like in burnout syndromes and, thirdly, hyperactivity during manic episodes. The Dysregulation of Mood, Energy, and Social Rhythms Syndrome (DYMERS), the second level of the scale, is proposed as a working hypothesis. DYMERS is also seen as a vulnerable condition that may evolve in other disorders (including BD) according to the individual susceptibility (including genetic predisposition) and the specific nature/level of the stressor.

Circadian immunity from bench to bedside: a practical guide

The immune system is built to counteract unpredictable threats, yet it relies on predictable cycles of activity to function properly. Daily rhythms in immune function are an expanding area of study, and many originate from a genetically based timekeeping mechanism known as the circadian clock. The challenge is how to harness these biological rhythms to improve medical interventions. Here, we review recent literature documenting how circadian clocks organize fundamental innate and adaptive immune activities, the immunologic consequences of circadian rhythm and sleep disruption, and persisting knowledge gaps in the field. We then consider the evidence linking circadian rhythms to vaccination, an important clinical realization of immune function. Finally, we discuss practical steps to translate circadian immunity to the patient's bedside.

Effect of extreme temperatures on asthma hospital visits: Modification by event characteristics and healthy behaviors

Although ambient temperature has been linked to asthma exacerbation, impacts associated with extreme temperature events remain unclear. This study aims to identify the events characteristics that elevate risk of asthma hospital visits, and to assess whether healthy behavior changes due to the COVID-19 prevention and control policy may modify the relationships. Data of asthma hospital visits from all medical facilities in Shenzhen, China during 2016-2020 were assessed in relation to extreme temperature events using a distributed lag model. Stratified analysis was conducted by gender, age and hospital department to identify susceptible populations. Through events defined by various duration days and temperature thresholds, we explored the modification by events intensity, length, occurrence time and healthy behaviors. The cumulative relative risk of asthma during heat waves compared to other days was 1.06 (95%CI: 1.00-1.13) and for cold spells was 1.17 (95%CI: 1.05-1.30), and that of males and school-aged children were generally higher than other sub-groups. There were significant effects of heat waves and cold spells on asthma hospital visits when the mean temperature was above 90th percentile (30 °C) and below 10th percentile (14 °C) respectively, and the relative risks were higher when events lasted longer, became stronger, occurred in daytime and in early summer or winter. During the healthy behaviors maintaining period, the risk of heat waves increased whilst the risk of cold spells reduced. Extreme temperatures may pose considerable impact on asthma and the health effect can be modified by the event characteristics and anti-epidemic healthy behaviors. Strategies of asthma control should consider the heightened threats of the intense and frequent extreme temperature events in the context of climate change.

The prevalence of childhood asthma: interpreting falling rates in the context of shifting measurement and the COVID-19 pandemic

PURPOSE OF REVIEW

The estimated prevalence of childhood asthma in the United States, as measured by the National Health Information Survey (NHIS), has decreased by 30% since 2017. This review provides context for observed changes in asthma rates by describing recent shifts in NHIS data collection and analysis, and considers whether the COVID-19 pandemic might impact asthma prevalence in years to come.

RECENT FINDINGS

The NHIS underwent a planned redesign in 2019 with updated sampling weights to better match the U.S. population. In early 2020, the COVID-19 pandemic resulted in unplanned modifications to NHIS implementation, which may have included fewer children from populations at a heightened risk for asthma. Decreasing prevalence estimates in recent years are likely at least in part due to these survey changes rather than true epidemiologic shift. However, pandemic-related changes to risk factors for childhood asthma (including exposure to rhinovirus infections and allergic sensitization) may also influence prevalence in the future.

SUMMARY

Recent changes in estimated rates of childhood asthma in the USA are likely driven by changes to survey methods and implementation, both before and during the COVID-19 pandemic. Additional years of data are needed to determine whether a true shift in disease prevalence is occurring.

Age-dependent rebound in asthma exacerbations after COVID-19 lockdown

Background

Virus mitigation measures enacted early in the coronavirus infectious disease 2019 (COVID-19) pandemic suppressed common respiratory viruses and reduced the number of obstructive lung disease exacerbations. However, many localities began to ease these precautions in the year 2021, leading to a resurgence of non-COVID viruses. How asthma and chronic obstructive pulmonary disease (COPD) activity responded to this upswing in viral abundance is unclear.

Objective

Our aim was to examine how viral resurgence during the relaxation of COVID-19 restrictions affected asthma and COPD exacerbations.

Methods

We analyzed electronic medical records for emergency department (ED) respiratory virus positivity, asthma visits, and COPD visits. We compared the 52-week interval before the COVID-19 restrictions (the pre-lockdown period [March 22, 2019-March 19, 2020]), the 52-week period immediately following enactment of the restrictions (the lockdown period [March 20, 2020-March 18, 2021]), and the 52-week period thereafter (the post-lockdown period [March 19, 2021-March 18, 2022]). We used MetaCYCLE to analyze seasonal trends in our data.

Results

The post-lockdown period was marked by a 400% increase in viral positivity compared with during the lockdown period. Asthma- and COPD-related ED visits each rose 37% compared with during the lockdown, with the rebound in asthma ED visits concentrated in individuals younger than 20 years. Interestingly, after the lockdown period, asthma ED visits overcorrected in children younger than 5 years, rising 81% compared with before the lockdown. Seasonal rhythms in asthma and COPD exacerbations were suppressed during the lockdown and recovered after the lockdown.

Conclusions

COVID-19 precautions had the unexpected effect of magnifying early-childhood asthma activity once common respiratory viruses recurred. These results may have implications for the future use of virus mitigation strategies in young children.