Exercise capacity after COVID-related multisystem inflammatory syndrome in children-A cross-sectional study

Background

After recovery from COVID-19 associated multisystem inflammatory syndrome in children (MISC), exercise restrictions were advised for 6 months. Studies done to assess exercise capacity at 3–6 months post recovery from MISC, prior to withdrawal of exercise restrictions, yielded varying information. Whether their exercise capacity was on par with their peers at/beyond 1-year post-recovery needed to be assessed.

Objectives

Primary: To compare the exercise capacity between children with a history of MISC and unaffected children

Secondary: To compare the exercise capacity between a) children with a history of MISC and children with a history of COVID but not MISC b) children with a history of COVID but not MISC and unaffected children.

Methods

Children (aged ≥8 years) who had recovered from MISC >1-year ago (n = 21) were compared with unaffected children (n = 42) and children who had COVID but not MISC (n = 21) respectively using cardiopulmonary exercise testing (CPET). Comparisons were made between 1. Post-MISC vs unaffected 2. Post-MISC vs post-COVID 3. Post-COVID vs unaffected.

Results

Compared with unaffected children, post-MISC and post-COVID groups had similar peak oxygen uptake (VO₂ max) but significantly lesser exercise duration. Children who were very sick during their hospitalization for MISC had an exercise capacity comparable to others in the post-MISC group. Overweight/obese children in post-MISC group had a significantly lesser exercise capacity. But, the numbers of overweight/obese children and very sick children were not adequate to run a separate sub-group analysis.

Conclusions

At/beyond 1 year post-recovery from MISC, exercise capacity was comparable to healthy children and children who had COVID but not MISC, but exercise duration was significantly less. Overweight/obese children need to be followed up longer with emphasis on regular exercises. Children who were very sick during MISC hospitalization had recovered their exercise capacity.