Background & aims: Children with acute lymphoblastic leukemia (ALL) receive high doses dexamethasone during treatment, which induce acute side effects. The aims of the current study were to... Show moreBackground & aims: Children with acute lymphoblastic leukemia (ALL) receive high doses dexamethasone during treatment, which induce acute side effects. The aims of the current study were to determine the influence of a five-day dexamethasone course on changes in leptin, fat mass, BMI, hunger, sleep and fatigue and to explore associations between these changes.Methods: Pediatric ALL patients were included during maintenance treatment. Data was collected before (T1) and after (T2) a five-day dexamethasone course (6 mg/m(2)/day). BMI, fat mass (bioelectrical impedance analysis) and leptin were assessed on both timepoints, as well as parent-reported questionnaires regarding hunger, fatigue and sleep problems. Changes between T1 and T2 were assessed using paired tests. Correlation coefficients were calculated to assess associations between these changes (Delta scores: T2-T1). Univariable regression models were estimated to study associations between covariates and elevated leptin.Results: We included 105 children with median age 5.4 years (range 3.0-18.8). Leptin and fat mass, as well as hunger scores, fatigue and sleep deteriorated after five days of dexamethasone (p < 0.001), in contrast to BMI (p = 0.12). No correlations between delta leptin and delta fat mass, BMI, hunger, fatigue or sleep were found. Elevated leptin on T1 was associated with older age (odds ratio (OR) 1.51, 95%-confidence interval (95%-CI) 1.28-1.77), higher fat mass (OR 1.19, 95%-CI 1.07-1.33) and earlier maintenance week (OR 0.96, 95%-CI 0.92-0.99).Conclusions: Five days of high dose dexamethasone treatment lead to direct and significant changes in leptin, hunger scores and fat mass. Since children with ALL are at increased risk for metabolic adverse events, understanding underlying mechanisms is important, and a dexamethasone-induced state of acute leptin resistance might play a role. Show less