Tetrahydrocannabinol in Pediatrics: Room for Improvement?

Introduction: The use of medical cannabis in pediatrics is not common in clinical practice, and there is a lack of prospective studies, especially in pediatric subpopulations. This study aimed to provide data on the off-label administration of tetrahydrocannabinol (∆9-THC) in a pediatric tertiary center in Austria. Methods: A retrospective data analysis was performed to assess the use of ∆9-THC at the Department of Pediatrics and Adolescent Medicine at the Comprehensive Center of Pediatrics (Medical University Vienna) from 2016 to 2018. The use of ∆9-THC in the Pediatric Department at the Medical University Vienna between 2016 and 2018 was analyzed using a retrospective design. Results: The most common diagnoses of patients receiving ∆9-THC were brain cancer and genetic diseases, including inborn metabolic disorders. The 32 patients who had received ∆9-THC had an arithmetic mean of 9.42 diagnoses and were treated with an arithmetic mean of 13.52 other drugs. Eleven of the 32 patients died by the end of the study period, indicating palliative use. Conclusion: The data shows that only severely ill patients were treated with ∆9-THC. A lack of information on the drug's indications, duration, and dosage was noticed in the files, which could represent problems for patient safety.

Macrophage-associated markers of metaflammation are linked to metabolic dysfunction in pediatric obesity.

BACKGPOUND: Metabolically driven chronic low-grade adipose tissue inflammation, so-called metaflammation, is a central feature in obesity. This inflammatory tone is largely driven by adipose tissue macrophages (ATM), which express pro- and anti-inflammatory markers and cytokines such as, e.g., IL-1 receptor antagonist (IL-1RA), CD163 and osteopontin (OPN). Metaflammation ultimately leads to the development of cardiometabolic diseases. This study aimed to evaluate the association between selected adipose tissue macrophage-associated markers and metabolic comorbidities in pediatric obesity. METHODS: From a pediatric cohort with obesity (n = 108), clinically thoroughly characterized including diverse routine blood parameters, oral glucose tolerance test and liver MRI, plasma IL-1RA, soluble (s)CD163 and OPN were measured by ELISA. RESULTS: We observed significantly higher IL-1RA, sCD163, and OPN levels in the plasma of children with metabolic-dysfunction associated fatty liver disease (MAFLD) and metabolic syndrome. Moreover, IL-1RA and sCD163 correlated with hepatic disease and apoptosis markers alanine aminotransferase and CK-18. IL-1RA concentrations additionally correlated with insulin resistance, while children with disturbed glucose metabolism had significantly higher levels of sCD163. CONCLUSION: MAFLD and other metabolic disorders in pediatric patients with obesity are associated with an elevation of adipose tissue macrophage-related inflammation markers.

Risk Scores for Metabolic Dysfunction-Associated Fatty Liver Disease in Pediatric Obesity.

INTRODUCTION: Early noninvasive detection of incipient liver damage is crucial to prevent long-term adverse health outcomes. A variety of scores to assess liver status have been proposed, mostly for adult populations. Validation of noninvasive hepatic scores to identify children at risk of metabolic dysfunction-associated fatty liver disease (MAFLD) is a gap in research, particularly in youth with severe obesity considering pubertal stage and sex. METHODS: In a well-characterized pediatric population aged 9-19 years (n = 115), 19 published liver scores were analyzed. The area under the receiver operating characteristic curve (AUROC) for determination of MAFLD as assessed by magnetic resonance imaging was calculated. RESULTS: The pediatric indices PNFI, B-AST, and M-APRI and several scores developed in adults significantly differed in children with MAFLD compared to children without, while some established indices did not. Only nonalcoholic fatty liver disease liver fat score (NAFLD-LFS) and the model by Cao et al. [PLoS One. 2013;8(12):e82092] showed acceptable predictive accuracy (AUROC >0.8) independently of pubertal stage and sex. When stratifying for pubertal stage and sex, the GSG-Index was superior in pubertal girls, and NAFLD-LFS performed best in pubertal boys. CONCLUSION: NAFLD-LFS and the model by Cao et al. [PLoS One. 2013;8(12):e82092] were well suited to predict MAFLD in youth with severe obesity. In pubertal children, GSG-Index and NAFLD-LFS performed best in girls and boys, respectively.

Plasma Myostatin Increases with Age in Male Youth and Negatively Correlates with Vitamin D in Severe Pediatric Obesity.

Obesity already causes non-communicable diseases during childhood, but the mechanisms of disease development are insufficiently understood. Myokines such as myostatin and irisin are muscle-derived factors possibly involved in obesity-associated diseases. This explorative study aims to investigate whether myostatin and irisin are associated with metabolic parameters, including the vitamin D status in pediatric patients with severe obesity. Clinical, anthropometric and laboratory data from 108 patients with severe obesity (>97th percentile) aged between 9 and 19 years were assessed. Myostatin, its antagonist follistatin, and irisin, were measured from plasma by ELISA. Myostatin concentrations, particularly in males, positively correlated with age and pubertal stage, as well as metabolic parameters such as insulin resistance. Irisin concentrations correlated positively with HDL and negatively with LDL cholesterol values. For follistatin, the associations with age and pubertal stage were inverse. Strikingly, a negative correlation of myostatin with serum vitamin D levels was observed that remained significant after adjusting for age and pubertal stage. In conclusion, there is an independent association of low vitamin D and elevated myostatin levels. Further research may focus on investigating means to prevent increased myostatin levels in interventional studies, which might open several venues to putative options to treat and prevent obesity-associated diseases.

Vascular access for lipid apheresis: a challenge in young children with homozygous familial hypercholesterolemia.

BACKGROUND: Homozygous familial hypercholesterolemia (hoFH) is a rare genetic disorder leading to extremely increased LDL-cholesterol (LDL-C), resulting in high cardiovascular risk in early childhood. Lipid apheresis (LA) is an effective treatment and should be started as early as possible to prevent premature cardiovascular events. As peripheral punctures in children can be challenging due to small vessels and anxiety, this study aimed to evaluate feasibility and safety of central venous catheters (CVCs) as vascular access for LA in young children with hoFH. METHODS: Retrospective analysis (2016-2019) on four children with hoFH aged 3-5 years, performing weekly or biweekly LA with a CVC. RESULTS: LDL-C decreased by> 60%. In three children, the use of a permanent CVC for 698, 595, and 411 days, respectively, avoided difficult peripheral access, without the occurrence of occlusion or thrombosis. Unfortunately, one child had recurrent CVC-related infections and needed an arteriovenous fistula from the age of 5. Although the mean dwell time per catheter was 212 days, there were, as expected, severe side effects of early catheter infections with sepsis and accidental self-removal. Starting LA at an early age improved or stabilized carotid intima-media thickness (IMT) in three children. However, IMT did increase in one child caused by intolerance to peripheral punctures and LA interruption. CONCLUSIONS: Permanent CVCs are a viable temporary access choice for LA in young children with hoFH until peripheral venipuncture is practicable. The risk of CVC-related infections needs to be taken into account.

Tryptophan Metabolism Is Associated with BMI and Adipose Tissue Mass and Linked to Metabolic Disease in Pediatric Obesity.

The obesity epidemic has contributed to an escalating prevalence of metabolic diseases in children. Overnutrition leads to increased tryptophan uptake and availability. An association between the induction of the tryptophan catabolic pathway via indoleamine 2,3-dioxygenase (IDO) activity and obesity-related inflammation has been observed. This study aimed to investigate the impact of pediatric obesity on tryptophan metabolism and the potential relationship with metabolic disease. In this prospective cohort study, plasma kynurenine, tryptophan, and serotonin levels were measured by ELISA, and IDO activity was estimated by calculating the kynurenine/tryptophan ratio in a clinically characterized population with severe obesity (BMI ≥ 97th percentile) aged 9 to 19 (n = 125). IDO activity and its product kynurenine correlated with BMI z-score and body fat mass, whereas concentrations of serotonin, the alternative tryptophan metabolite, negatively correlated with these measures of adiposity. Kynurenine and tryptophan, but not serotonin levels, were associated with disturbed glucose metabolism. Tryptophan concentrations negatively correlated with adiponectin and were significantly higher in prediabetes and metabolically unhealthy obesity. In conclusion, BMI and body fat mass were associated with increased tryptophan catabolism via the kynurenine pathway and decreased serotonin production in children and adolescents with severe obesity. The resulting elevated kynurenine levels may contribute to metabolic disease in obesity.

The Effect of a Fat-Restricted Diet in Four Patients with Familial Chylomicronemia Syndrome: A Long-Term Follow-Up Study.

(1) Background: Familial chylomicronemia syndrome (FCS) is a very rare autosomal recessive disorder characterized by severely elevated triglycerides and clinical symptoms in early childhood mainly presenting with abdominal pain, acute pancreatitis and hepatosplenomegaly. Primary treatment is a lifelong very strict low-fat diet, which might be challenging in pediatric patients. So far, data about children with FCS are rare. The aim of this study was to show the familial chylomicronemia syndrome traffic light table for pediatric patients and to assess the dietary fat intake and impact on triglycerides in children with FCS. (2) Methods: We performed a retrospective analysis in four children (50% male) affected by FCS from the Department of Pediatrics and Adolescent Medicine, Medical University of Vienna between January 2002 and September 2020. (3) Results: The four patients presented with classical FCS symptoms and showed baseline triglycerides (TG) exceeding 30,000 mg/dL in two patients, 10,000 mg/dL and 2400 mg/dL in one patient each. After diagnosis, fat percentage of total daily caloric intake was decreased and resulted immediately in triglyceride reduction. In all patients, FCS was genetically confirmed by mutations in genes encoding lipoprotein lipase. Acute pancreatitis and hepatosplenomegaly disappeared under the fat-restricted diet. A FCS traffic light table was developed as a dietary tool for affected families. (4) Conclusions: A restriction of dietary fat between 10% to 26% of the total daily caloric intake was feasible and effective in the long-term treatment of genetically confirmed FCS in children and could reduce the risk for acute pancreatitis. The dietary tool, the pediatric FCS traffic light table and the age-appropriate portion sizes for patients between 1 to 18 years, supports children and their parents to achieve and adhere to the lifelong strict low-fat diet.

Circulating microRNAs 34a, 122, and 192 are linked to obesity-associated inflammation and metabolic disease in pediatric patients.

BACKGROUND: Obesity-associated chronic low-grade inflammation leads to dysregulation of central lipid and glucose metabolism pathways leading to metabolic disorders. MicroRNAs (miRNAs) are known to control regulators of metabolic homeostasis. We aimed to assess the relationship of circulating miRNAs with inflammatory modulators and metabolic disorders in pediatric obesity. METHODS: From a pediatric cohort with severe obesity (n = 109), clinically thoroughly characterized including diverse routine blood parameters, oral glucose tolerance test, and liver MRI, a panel of 16 circulating miRNAs was quantified using qRT-PCR. Additionally, markers of inflammation TNFα, IL1 receptor antagonist, procalcitonin, CRP, and IL-6 were measured. RESULTS: Markers of obesity-associated inflammation, TNFα, IL-1Ra, and procalcitonin, all significantly correlated with concentrations of miRNAs 122 and 192. Concentrations of these miRNAs negatively correlated with serum adiponectin and were among those strongly linked to parameters of dyslipidemia and liver function. Moreover, miRNA122 concentrations correlated with HOMA-IR. Several miRNA levels including miRNAs 34a, 93, 122, and 192 were statistically significantly differing between individuals with prediabetes, impaired glucose tolerance, metabolic syndrome, or nonalcoholic fatty liver disease compared to the respective controls. Additionally, miRNA 192 was significantly elevated in metabolically unhealthy obesity. CONCLUSIONS: A miRNA pattern associated with obesity-associated inflammation and comorbidities may be used to distinguish metabolically healthy from unhealthy pediatric patients with obesity. Moreover, these changes in epigenetic regulation could potentially be involved in the etiology of obesity-linked metabolic disease in children and adolescents.

A branched-chain amino acid-based metabolic score can predict liver fat in children and adolescents with severe obesity.

BACKGROUND: Eighty percent of adolescents with severe obesity suffer from non-alcoholic fatty liver disease (NAFLD). Non-invasive prediction models have been tested in adults, however, they performed poorly in paediatric populations. OBJECTIVE: This study aimed to investigate novel biomarkers for NAFLD and to develop a score that predicts liver fat in youth with severe obesity. METHODS: From a population with a BMI >97th percentile aged 9-19 years (n = 68), clinically thoroughly characterized including MRI-derived proton density fat fraction (MRI-PDFF), amino acids and acylcarnitines were measured by HPLC-MS. RESULTS: In children with NAFLD, higher levels of plasma branched-chain amino acids (BCAA) were determined. BCAAs correlated with MRI-PDFF (R = 0.46, p < .01). We identified a linear regression model adjusted for age, sex and pubertal stage consisting of BCAAs, ALT, GGT, ferritin and insulin that predicted MRI-PDFF (R = 0.75, p < .01). ROC analysis of this model revealed AUCs of 0.85, 0.85 and 0.92 for the detection of any, moderate and severe steatosis, respectively, thus markedly outperforming previously published scores. CONCLUSION: BCAAs could be an important link between obesity and other metabolic pathways. A BCAA-based metabolic score can predict steatosis grade in high-risk children and adolescents and may provide a feasible alternative to sophisticated methods like MRI or biopsy in the future.