Longitudinal anthropometry and body composition in children with SARS-CoV-2-associated multisystem inflammatory syndrome

Objectives: Acute COVID-19 infection has been shown to negatively affect body composition among adult and malnourished or obesity children. Our aim is to longitudinally evaluate body composition in children affected by the Multisystem Inflammatory Syndrome (MIS-C). Methods: In this cohort study we recruited 40 patients affected by MIS-C, aged 2 to 18 years old, who were admitted in our clinic between December 2020 and February 2021. Physical examination for each participant included weight, height, body mass index (BMI) z-score, circumferences, skinfolds assessment. The same measurements were repeated during outpatient follow-up at 10 (T2), 30 (T3), 90 (T4) and 180 (T5) after hospital discharge. Fat mass and fat free mass were calculated according to skinfolds predictive equations for children and adolescents. A control group was randomly selected among patients attending a pediatric nutritional outpatient clinic. Results: BMI z-score significantly decrease between pre-admission and hospital discharge. Similarly, arm circumference (AC) z-score, arm muscular area (AMA) z-score, and arm fat area (AFA) z-score significantly decreased, during hospital stay. Fat mass index (FMI) significantly increased over time, peaking at T3. Fat free mass index (FFMI) decreased during hospitalization. Conclusion: To the best of our knowledge this is the first study to assess body composition in a numerically large pediatric MIS-C population from acute infection to six months after triggering event. FMI and anthropometric parameters linked to fat deposits were significantly higher six months after acute event. Thus, limiting physical activity and having sedentary lifestyle may lead to an accumulation of adipose tissue even in healthy children who experienced MIS-C and long hospitalization.