BACKGROUND\nMETHOD\nINTERPRETATION\nAdults with SARS-CoV-2 infection have shown higher risks of dyslipidaemia and abnormal body mass index (BMI). Whether similar associations exist in children and adolescents is unclear.\nWe did a retrospective cohort study using the RECOVER paediatric Electronic Health Record (EHR) datasets from 25 US children's hospitals, covering March 2020 to September 2023. For dyslipidaemia analyses, we included 384,289 patients aged 0-21 years with at least 6 months of follow-up and 1,080,413 COVID-19-negative controls. For BMI analyses, we included 285,559 patients aged 2-21 years and 817,315 controls. Documented infection was defined as a positive PCR, serology, or antigen test, or a clinical diagnosis of COVID-19 or post-acute sequelae of SARS-CoV-2. Outcomes were new diagnoses of dyslipidaemia, defined by laboratory thresholds for total cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, and non-HDL cholesterol, and abnormal BMI (BMI-for-age ≥95th percentile at ages 2-19 years or BMI ≥30 kg/m2 at ages 19-21 years). Adjusted relative risks (aRRs) were estimated using propensity score-stratified Poisson regression. Sensitivity analyses included empirical calibration with negative control outcomes and stratification by baseline obesity.\nChildren and adolescents with documented COVID-19 were associated with higher risks of new-onset dyslipidaemia and abnormal BMI in the post-acute period compared with COVID-19-negative peers. Associations were consistent across lipid fractions, remained after empirical calibration, and were similar after accounting for baseline obesity.
