The epidemic of childhood obesity and the COVID-19 pandemic: metabolic characteristics and effects of therapy.

INTRODUCTION: The aim of the study was to analyse whether children whose obesity occurred during the pandemic differed metabolically from children who were obese earlier and to assess the effect of one-year treatment following the end of pandemic restrictions. MATERIAL AND METHODS: A prospective study of 55 children aged 10-18 years who were referred to the outpatient's clinic during the pandemic due to obesity was conducted. The following clinical data were analysed: time of obesity onset, body mass index (BMI) z-score, body mass composition, blood pressure, abdominal ultrasound, biochemical parameters of lipid and carbohydrate metabolism, aminotransferases and fetuin-A concentration. Participants received recommendations to improve their diet and increase physical activity (PA). After 3, 6 and 12 months, we assessed: BMI z-score, compliance with recommendations, and biochemical parameters. RESULTS: No significant differences between pandemic obesity and non-pandemic obesity were observed at the beginning and after one year. Children who followed the dietary recommendations had a significantly lower BMI z-score after 3 months (median 2.08 vs. 1.89, p = 0.044). Children who reported increased PA (47.3%) also showed lower BMI z-scores after 6 (median 2.12 vs. 1.86, p = 0.53) and 12 months (median 2.12 vs. 1.78, p = 0.008). The beneficial effect of PA was demonstrated in lower levels of fetuin-A in children with increased PA after 6 months (median 480 vs. 395 mg/ml, p = 0.07). CONCLUSIONS: The "obesity pandemic" does not appear to be metabolically distinct from obesity that developed earlier and lasted longer. An increase in PA and compliance with dietary recommendations remain important elements of therapy, particularly in the context of metabolic complications. Fetuin-A may serve as a potential parameter for assessing compliance with PA recommendations and the rate of obesity progression.