Characterization of peripheral blood T follicular helper (TFH) cells in patients with type 1 Gaucher disease and carriers.

BACKGROUND: Gaucher disease (GD) is the most common autosomal recessive lipid storage disease. In this study, the changes in TFH cells and IL-4 and IL-21 cytokines in blood samples of GD patients, carriers and healthy volunteers were investigated. METHODS: Two pretreatment type 1 GD patients, 20 currently treated type 1 GD patients, 6 carriers, and 27 healthy volunteers were enrolled in the study. TFH cell (CD45RA-CD4+CXCR5+) number, phenotype (PD1, ICOS expression), and cytokine production (IL-21, IL-4) were assessed via flow cytometric assays. RESULTS: No significant differences were found between the groups with respect to the number, frequency and PD1 or ICOS expression of TFH cells between healthy controls, patients and carriers. However, IL-4+ TFH cells were significantly reduced both in percent and number in the treated GD patients compared with healthy controls (p < 0.05). Interestingly, the IL-21+ TFH cell number was increased in treated GD patients. When TFH cells were examined based on CXCR3 expression, the frequency of the PD1+Th17-Th2-like fraction (CXCR3-) was found to be significantly increased in treated GD patients. CONCLUSION: To our knowledge, this is the first study to assess TFH cells in GD patients, and to show that the production of IL-4 and IL-21 by TFH cells and their subsets may be altered in type 1 GD patients.

Evaluation of the effect of obesity, dietary glycemic index and metabolic profiles on the cardiovascular risk in children with classical phenylketonuria.

OBJECTIVES: To compare the glycemic index(GI),obesity,echocardiographic,and arterial stiffness measurements with the healthy control group to evaluate the cardiovascular risk of pediatric classical phenylketonuria(PKU). METHODS: The study was a prospective observational,involving 104 pediatric volunteers between 2019 and 2020.Two groups were formed:the PKU patient group and the healthy control group.These two groups were further divided into three subgroups:obese,overweight,and normal weight.The patients' anthropometric measurements,body fat analysis,biochemical analysis, GI and glycemic load(GL),arterial stiffness measurements,and echocardiographic findings were recorded. RESULTS: The PKU patient group's glucose,total cholesterol,LDL,and HDL values were significantly lower than the healthy control group(p = 0.010 for glucose and p = 0.001 for total cholesterol,LDL and HDL).Triglyceride levels were higher in the PKU patient group than in the healthy controls(109.6 vs. 76.7 mg/dl,p = 0.001). GI and GL were significantly lower in the PKU patient group than in the healthy control group(GI 453 vs. 392.9,p = 0.017 and GL 101.1 vs. 85.5,p = 0.036).Left ventricular mass(LVM)-z-score and LVM index were significantly higher in the PKU group than in the healthy control group(LVM z-score 0.9 vs. 0.5,p = 0.014 and LVM index 38.9 vs. 32.7 g/m2.7,p = 0.001). A moderately statistically significant positive correlation was found between the mean phenylalanine(phe) value and pulse wave velocity(PWV) among the PKU patient groups(R: 0.477,p < 0.001).A moderately statistically significant positive correlation was also found between waist circumference and PWV in the PKU patient group(R:0.541, p < 0.001). CONCLUSIONS: Our study found that close follow-up of phe levels and PWV is more critical than obesity, GI, and GL in the cardiovascular evaluation of classical PKU patients.A large number of multicenter pediatric studies are needed in this area.

PPM1K defects cause mild maple syrup urine disease: The second case in the literature.

Maple syrup urine disease (MSUD) is an inborn error of metabolism caused by the insufficient catabolism of branched-chain amino acids. BCKDHA, BCKDHB, DBT, and DLD encode the subunits of the branched-chain α-ketoacid dehydrogenase complex, which is responsible for the catabolism of these amino acids. Biallelic pathogenic variants in BCKDHA, BCKDHB, or DBT are characteristic of MSUD. In addition, a patient with a PPM1K defect was previously reported. PPM1K dephosphorylates and activates the enzyme complex. We report a patient with MSUD with mild findings and elevated BCAA levels carrying a novel homozygous start-loss variant in PPM1K. Our study offers further evidence that PPM1K variants cause mild MSUD.

The etiology and age-related properties of patients with delirium in coronary intensive care unit and its effects on inhospital and follow up prognosis.

Background and purpose: Delirium is a syndrome frequently encountered in intensive care and associated with a poor prognosis. Intensive care delirium is mostly based on general and palliative intensive care data in the literature. In this study, we aimed to investigate the incidence of delirium in coronary intensive care unit (CICU), related factors, its relationship with inhospital and follow up prognosis, incidence of age-related delirium and its effect on outcomes. Methods: This study was conducted with patients hospitalized in CICU of a tertiary university hospital between 01 August 2017 and 01 August 2018. Files of all patients were examined in details, and demographic, clinic and laboratory parameters were recorded. Patients confirmed with psychiatry consultation were included in the groups of patients who developed delirium. Patients were divided into groups with and without delirium developed, and baseline features, inhospital and follow up prognoses were investigated. In addition, patients were divided into four groups as <65 years old, 65-75 yo, 75-84 yo and> 85 yo, and the incidence of delirium, related factors and prognoses were compared among these groups. Results: A total of 1108 patients (mean age: 64.4 ± 13.9 years; 66% men) who were followed in the intensive care unit with variable indications were included in the study. Of all patients 11.1% developed delirium in the CICU. Patients who developed delirium were older, comorbidities were more frequent, and these patients showed increased inflammation findings, and significant increase in inhospital mortality compared to those who did not develop delirium (p<0.05). At median 9-month follow up period, rehospitalization, reinfarction, cognitive dysfunction, initiation of psychiatric therapy and mortality were significantly higher in the delirium group (p<0.05). When patients who developed delirium were divided into four groups by age and analyzed, incidence of delirium and mortality rate in delirium group were significantly increased by age (p<0.05). Conclusion: Development of delirium in coronary intensive care unit is associated with increased inhospital and follow up morbidity and mortality. Delirium is more commonly seen in geriatric patients and those with comorbidity, and is associated with a poorer prognosis. High-risk patients should be more carefully monitored for the risk of delirium.

Neutropenia and Increased Mean Corpuscular Volume (MCV) With Abnormal Neurologic Findings: A Case of Cobalamin D Deficiency.

BACKGROUND: Disorders of intracellular cobalamin (Cbl) metabolism are classified from A to J according to biochemical phenotype, and genetic and complementation analyses. CblD-deficient patients present with developmental, hematologic, neurologic, and metabolic findings. CLINICAL OBSERVATION: An 11-year-old boy presented with neutropenia, increased mean corpuscular volume, psychomotor retardation, and seizures. His plasma total homocysteine and urinary methylmalonic acid levels were elevated, and a homozygous nonsense mutation [p. R250X (c.748C>T] leading to premature termination of translation was identified in the MMADHC gene, which was compatible with CblD defect. CONCLUSION: In the presence of increased mean corpuscular volume and other hematologic manifestations, such as leukopenia, thrombocytopenia, and megaloblastic anemia, with severe nonspecific or mild neurologic symptoms, Cbl synthesis defects should be considered.

The Inflammation-Based Glasgow Prognostic Score as a Prognostic Factor in Patients with Intensive Cardiovascular Care Unit.

Background: The Glasgow prognostic score (GPS), which is obtained from a combination of C-reactive protein (CRP) and serum albumin level, predicts poor prognoses in many cancer types. Systemic inflammation also plays an important role in pathogenesis of cardiovascular diseases. In this study, we aimed to investigate the effect of inflammation-based GPS on in-hospital and long-term outcomes in patients hospitalized in intensive cardiovascular care unit (ICCU). Methods: A total of 1004 consecutive patients admitted to ICCU were included in the study, and patients were divided into three groups based on albumin and CRP values as GPS 0, 1, and 2. Patients' demographic, clinic, and laboratory findings were recorded. In-hospital and one-year mortality rates were compared between groups. Results: Mortality occurred in 109 (10.8%) patients in in-hospital period, 82 (8.1%) patients during follow-up period, and thus, cumulative mortality occurred in 191 (19.0%) patients. Patients with a high GPS score had a higher rate of comorbidities and represented increased inflammatory evidence. In the multivariate regression model there was independent association with in-hospital mortality in GPS 1 patients compared to GPS 0 patients (Odds ratio, (OR); 5.52, 95% CI: 1.2⁻16.91, p = 0.025) and in GPS 2 patients compared to GPS 0 patients (OR; 7.01, 95% CI: 1.39⁻35.15, p = 0.018). A higher GPS score was also associated with a prolonged ICCU and hospital stay, and increased re-hospitalization in the follow-up period. Conclusion: Inflammation based GPS is a practical tool in the prediction of worse prognosis both in in-hospital and one-year follow-up periods in ICCU patients.

Long-term efficacy of lipoprotein apheresis in the management of familial hypercholesterolaemia: Application of two different apheresis techniques in childhood.

Lipoprotein apheresis is used to treat patients with familial hypercholesterolemia (FH). The aim of the present study is to clarify the lipoprotein apheresis procedure performed by cascade filtration (CF) or double filtration plasmapheresis (DFPP) on pediatric patients in terms of side effects, laboratory results and cardiovascular follow-up. Data of ten pediatric patients were analyzed retrospectively. The average age of the patients was 12.1 ± 3.4 years. Percentage of long term reduction of low density lipoprotein cholesterol was 62.35 ± 7.19% (n = 3) for CF and 63.66 ± 6.63% (n = 3) for CF plus DFPP, 64.79 ± 8.29% (n = 7) for DFPP. Cardiovascular disease was not detected in thirty percent of the patients. Lesions remained stable in fifty percent of patients with heart valve lesions. Valvular lesions worsened in twenty percent of patients. Lipoprotein apheresis can be used effectively and successfully in pediatric patients as well as adults for homozygous FH.

Tyrosinemia type II: Novel mutations in TAT in a boy with unusual presentation.

Tyrosinemia type II is a rare autosomal recessive disorder caused by deficiency of tyrosine aminotransferase (TAT). It may occur with ocular and cutaneous symptoms with or without mental retardation, but epileptic seizure is a rare presentation of this disease. Herein we report the clinical, biochemical and genetic features of a 4-year-old boy who presented with afebrile seizure and photophobia. Genomic DNA was obtained from peripheral blood leukocytes from the whole family. Sequencing analysis was performed using the MiSeq next-generation sequencing platform. Sequencing of TAT indicated two new homozygous mutations p.L312P (c.935T>C) and p.T408M (c.1223C>T) for the proband and his asymptomatic sister. During a 2 year follow-up period, the patient had overall poor compliance with protein-restricted diet, but his asymptomatic sister had good compliance with the diet. Cognitive function of the patient worsened steadily, but his asymptomatic sister maintained normal mental status. Tyrosinemia type II should be considered in the differential diagnosis of children presenting with epileptic seizure and photophobia; furthermore, early diagnosis and protein-restricted regimen are important to reduce the risk of long-term complications of tyrosinemia type II such as mental disability.

The Effects of Ketogenic Diet on Seizures, Cognitive Functions, and Other Neurological Disorders in Classical Phenotype of Glucose Transporter 1 Deficiency Syndrome.

OBJECTIVES: The purpose of this study was to characterize patients who were diagnosed with glucose transporter protein 1 deficiency syndrome (Glut1D), and also to assess the efficacy of ketogenic diet (KD) therapy on seizure control, cognitive functions, and other neurological disorders. PATIENTS AND METHODS: We studied six unrelated patients with the classical phenotype of Glut1D, focusing on clinical and laboratory features, the KD therapy and outcome over the 25-month follow-up period. RESULTS: Five patients became seizure-free with the onset of ketosis, and anticonvulsants were discontinued. Other neurological features such as ataxia, spasticity, and dystonia showed a less striking improvement than seizure control. There was no significant change in the intelligence quotient (IQ) level or microcephaly. In all patients, alertness, concentration, motivation, and activity resulted in a moderate improvement of variable degree. The early-onset adverse effects of KD were observed in five patients. The KD regimen failed in one patient, therefore, his diet was changed with an alternative to KD. CONCLUSIONS: Treatment with KD resulted in a marked improvement in seizures and cognitive functions but its effect appeared to be less striking on the other neurological disorders of the patients. When the classic KD is not tolerated, an alternative to KD may be helpful.

Clinical, Electrodiagnostic, and Genetic Features of Tangier Disease in an Adolescent Girl with Presentation of Peripheral Neuropathy.

Tangier disease (TD) is a rare, autosomal recessive inherited disorder caused by a mutation in the adenosine triphosphate-binding cassette transporter 1 (ABCA1) gene, which results in a decrease in plasma high-density lipoprotein (HDL) levels. Peripheral neuropathy can be seen in approximately 50% of patients with TD, which usually occurs after the age of 15 years, and is characterized by relapsing-remitting mono- or polyneuropathy or syringomyelia-like neuropathy. Herein, we report a 16-year-old female patient who was initially diagnosed with peripheral neuropathy at the age of 13 years. Whole exome sequencing was performed, and a nonsense mutation (p.Arg1817X) in ABCA1 was identified. The patient was investigated for systemic findings of TD after the genetic diagnosis was made, and low (< 5 mg/dL) levels of HDL cholesterol were detected by lipid electrophoresis. Other family members were reexamined after the diagnosis of the proband, and asymptomatic sister of the proband was diagnosed with TD. We would like to emphasize that TD should be considered in the differential diagnosis of pediatric patients presenting with peripheral neuropathy; furthermore detection of HDL levels by lipid electrophoresis is a simple but indicative diagnostic test.

Oxidative and chromosomal DNA damage in patients with type I Gaucher disease and carriers.

BACKGROUND AND AIMS: Gaucher disease (GD) is caused by a genetic deficiency of the beta-glucocerebrosidase enzyme which results in the accumulation of glucosylceramide in macrophages. This accumulation may induce oxidative stress, resulting in DNA damage in patients with GD. The aim of this study was to assess plasma 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and cytokinesis-block micronucleus cytome (CBMN-cyt) assay parameters in the peripheral blood lymphocytes of patients with GD and carriers, evaluate the possible associations of these values with GD, and determine whether they can be used as potential biomarkers in GD. METHODS: This study included 20 patients with type 1 GD, six carriers, and 27 age- and sex-matched healthy controls. CBMN-cyt assay parameters in peripheral blood lymphocytes of the patients with GD, carriers, and controls were evaluated and 8-OHdG levels in their plasma samples were measured. RESULTS: CBMN-cyt assay parameters in patients with GD and carriers were not significantly different when compared with controls (p > 0.05). However, plasma 8-OHdG levels were found to be higher in both patients with GD and carriers than in control subjects (p < 0.01). CONCLUSIONS: Oxidative DNA damage may be a useful prognostic tool, whereas the CBMN-cyt assay cannot be used as a predictive biomarker of GD.

Novel mutations of ABCA1 transporter in patients with Tangier disease and familial HDL deficiency.

The objective of the study was the characterization of ABCA1 gene mutations in 10 patients with extremely low HDL-cholesterol. Five patients (aged 6 months to 76 years) presented with splenomegaly and thrombocytopenia suggesting the diagnosis of Tangier disease (TD). Three of them were homozygous for novel mutations either in intron (c.4465-34A>G) or in exons (c.4376delT and c.5449C>T), predicted to encode truncated proteins. One patient was compound heterozygous for a nucleotide insertion (c.1758_1759insG), resulting in a truncated protein and for a nucleotide substitution c.4799A>G, resulting in a missense mutation (p.H1600R). The last TD patient, found to be heterozygous for a known mutation (p.D1009Y), had a complete defect in ABCA1-mediated cholesterol efflux in fibroblasts, suggesting the presence of a second undetected mutant allele. Among the other patients, four were asymptomatic, but one, with multiple risk factors, had severe peripheral artery disease. Three of these patients were heterozygous for known mutations (p.R130K+p.N1800H, p.R1068C, p.N1800H), while two were carriers of novel mutations (c.1195-27G>A and c.396_397insA), predicted to encode truncated proteins. The pathogenic effect of the two intronic mutations (c. 1195-27G>A and c.4465-34A>G) was demonstrated by the analysis of the transcripts of splicing reporter mutant minigenes expressed in COS-1 cells. Both mutations activated an intronic acceptor splice site which resulted in a partial intron retention in mature mRNA with the production of truncated proteins. This study confirms the allelic heterogeneity of TD and suggests that the diagnosis of TD must be considered in patients with an unexplained splenomegaly, associated with thrombocytopenia and hypocholesterolemia.

Hemophagocytic syndrome in a 4-month-old infant with biotinidase deficiency.

Hemophagocytic syndromes such as hemophagocytic lymphohistiocytosis (HLH) are life-threatening hyperinflammatory conditions caused by inherited or acquired immune disorders. Awareness of the clinical symptoms and diagnostic criteria for hemophagocytic syndromes is crucial to start timely life-saving therapy. We present a case of a 4-month-old boy presenting with HLH. However, the patient was subsequently diagnosed with biotinidase deficiency and was successfully treated with biotin-replacement therapy, upon which the hemophagocytic syndrome ceased. Subsequent laboratory evaluations revealed normal lymphocyte cytotoxicity and no mutations in genes associated with familial HLH were found. Biotinidase deficiency should be considered as a differential diagnosis of patients fulfilling HLH criteria.

Successful treatment of homozygous familial hypercholesterolemia using cascade filtration plasmapheresis.

OBJECTIVE: The aim of this study was to report the efficacy of low-density lipoprotein cholesterol (LDL-C) apheresisusing a cascade filtration system in pediatric patients with homozygous familial hypercholesterolemia (FH), and toclarify the associated adverse effects and difficulties. MATERIAL AND METHODS: LDL-C apheresis using a cascade filtration system was performed in 3 pediatric patientswith homozygous FH; in total, 120 apheresis sessions were performed. RESULTS: Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dL to 145 ± 43 mg/dL (p= 0.011). We observed an acute mean reduction in the plasma level of total cholesterol (57.9%), LDL-C (70.8%),and high-density lipoprotein cholesterol (HDL-C) (40.7%). Treatments were well tolerated. The most frequent clinicaladverse effects were hypotension in 3 sessions (2.5%), chills (1.7%) in 2 sessions, and nausea/vomiting in 3 sessions(2.5%). CONCLUSION: Our experience using the cascade filtration system with 3 patients included good clinical outcomes andlaboratory findings, safe usage, and minor adverse effects and technical problems. CONFLICT OF INTEREST: None declared.

Identifying the effects of excess weight, metabolic syndrome and insulin resistance on liver stiffness using ultrasound elastography in children.

BACKGROUND: Metabolic syndrome (MetS) and insulin resistance (IR) are known predictors of nonalcoholic fatty liver disease (NAFLD) which is one of the significant comorbidities of obesity. Obese children with MetS and IR are reported to be more likely to have advanced liver fibrosis compared to those without MetS or IR. The aim of this study is to determine the effects of excess weight, MetS and IR on liver fibrosis assessing liver stiffness in children using ultrasound elastography and compare gray scale ultrasonographic findings of hepatic steatosis (HS) with liver fibrosis. METHODS: The study group involved 131 overweight/obese children. The control group involved 50 healthy lean children. Groups were adjusted according to body mass index (BMI) and BMI-standard deviation scores (SDS). Liver stiffness measurements which are expressed by shear wave velocity (SWV) were performed for each individual. The study group was further subgrouped as children with MetS and without MetS, with IR and without IR. RESULTS: The mean SWV of liver was 1,07 ± 0,12 m/s in the control group and 1,15 ± 0,51 m/s in the study group. The difference was significant (p=0,047). SWV of liver was weakly correlated with age, BMI, BMI-SDS, Homeostatic Model Assessment-Insulin Resistance and high-density lipoprotein cholesterol. The mean SWV of the liver in the study group for children without MetS was 1,1 ± 0,44 m/s, with MetS was 1,23 ± 0,70 m/s. The difference was not significant (p=0,719). The mean SWV of the liver in the study group for children without IR was 1,02 ± 0,29 m/s, with IR was 1,24 ± 0,61 m/s. The difference was not significant (p=0,101). In multivariate regression analysis, the only independent factor affecting liver stiffness was BMI-SDS (OR:2,584, 95% CI: 1,255- 5,318, p=0,010). CONCLUSIONS: Obesity itself, regardless of MetS or IR seems to be the major problem affecting liver stiffness in this study. However, large scale longitudinal studies might clarify this issue.

A teenager boy with a novel variant of Sitosterolemia presented with pancytopenia.

BACKGROUND: Sitosterolemia, also known as phytosterolemia, results from increased intestinal absorption of plant sterols and decreased intestinal and biliary excretion of sterols, resulting in increased levels of plant sterols in the plasma. The most common symptoms include xanthomas, premature atherosclerosis, hemolytic anemia and macrothrombocytopenia, however delayed diagnosis or misdiagnosis also occur. PATIENT AND METHODS: Clinical exome sequencing was performed on a 10-year-old boy whom we followed up with signs of pancytopenia accompanied by macrothrombocytopenia and stomatocytosis. In addition, the blood sterol levels of the patient and his family were studied. RESULTS: A novel homozygous c.904 + 5G > C intronic variant was detected in ABCG5 gene in index case. The mother and father were identified as carriers. The blood plant sterol levels of the patient and his family were studied, and the levels in the patient confirmed Sitosterolemia. Sitosterol levels decreased dramatically with restricted diet and ezetimibe treatment. CONCLUSION: In children, signs of Sitosterolemia may be subtle and the only symptom may be hematological. Therefore, Sitosterolemia should be kept in mind in children with stomatocytosis and macrothrombocytopenia.

Three-Country Snapshot of Ornithine Transcarbamylase Deficiency.

X-linked ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle defect. The disease severity ranges from asymptomatic carrier state to severe neonatal presentation with hyperammonaemic encephalopathy. We audited the diagnosis and management of OTCD, using an online 12-question-survey that was sent to 75 metabolic centres in Turkey, France and the UK. Thirty-nine centres responded and 495 patients were reported in total. A total of 208 French patients were reported, including 71 (34%) males, 86 (41%) symptomatic and 51 (25%) asymptomatic females. Eighty-five Turkish patients included 32 (38%) males, 39 (46%) symptomatic and 14 (16%) asymptomatic females. Out of the 202 UK patients, 66 (33%) were male, 83 (41%) asymptomatic and 53 (26%) symptomatic females. A total of 19%, 12% and 7% of the patients presented with a neonatal-onset phenotype in France, Turkey and the UK, respectively. Vomiting, altered mental status and encephalopathy were the most common initial symptoms in all three countries. While 69% in France and 79% in Turkey were receiving protein restriction, 42% were on a protein-restricted diet in the UK. A total of 76%, 47% and 33% of patients were treated with ammonia scavengers in Turkey, France and the UK, respectively. The findings of our audit emphasize the differences and similarities in manifestations and management practices in three countries.

Phenylketonuria with acute myeloblastic leukemia in a 9-year-old boy: reporting a rare case.

Phenylketonuria is a genetic metabolic disorder resulting in phenylalanine accumulation in blood. Phenylacetate, which is an abnormal phenylalanine metabolities, was hypothesized to have anticancer activity. Two-years-old boy was diagnosed with classical phenylketonuria because of mental motor retardation. When the patient was 9-year-old, he developed acute myeloblastic leukemia. Here, we present the case with phenylketonuria and acute myeloblastic leukemia because of its extreme rarity.

Determining the effects of excess weight on renal cortical stiffness in children and adolescents with point Shear Wave Elastography.

AIM: To determine the early effects of excess weight on renal cortical stiffness in children and adolescents using point shear wave elastography (pSWE). MATERIALS AND METHODS: One hundred and forty-six overweight and obese children (43.2% male; mean age, 12.6±2.9 years: range 4.3-18) and 48 lean children (27.1% male: mean age, 12.4±3.4: range 4.8-18.9) were included in the study and control group, respectively. pSWE measurements of the two kidneys were performed. The mean value of shear wave velocity was compared between groups. RESULTS: The mean shear wave velocity was 2.79±0.53 m/s for the control subjects and 3.09±0.59 m/s for the overweight-obese subjects. The differences between the two groups were sta-tistically significant (p=0.001). There was no correlation between shear wave velocity and age or depth. A positive correlation was found between shear wave velocity and body mass index, body mass index-standard deviation score. CONCLUSION: Renal cortical stiffness was higher in children with excess weight than in lean children. This study is the first attempt at applying pSWE to investigate the early adverse effects of excess weight.

Evaluation of micronutrient levels in children and adolescents with obesity and their correlation with the components of metabolic syndrome.

BACKGROUND: Obesity is a significant public health problem worldwide. Vitamin deficiencies, developing due to monotype nutrition, are more likely to be observed in patients than healthy children. The present study evaluates vitamin and micronutrient levels in children and adolescents with obesity and metabolic syndrome compared to healthy controls. METHODS: The study included 73 patients with obesity, 64 patients with metabolic syndrome and 71 healthy children (control group) aged 10 to 16 years. Physical examinations were performed, and waist circumference and systolic blood pressure measurements were recorded. Fasting blood glucose, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, insulin, vitamin A, vitamin E, vitamin B1, vitamin B2, vitamin B6, vitamin B12, folic acid and free carnitine levels were analyzed. The homeostatic model of assessment-insulin resistance (HOMA-IR) index was calculated and recorded. RESULTS: The mean age of all patients was 11.9±2.6 years. The serum insulin level and HOMA-IR index were found to be significantly higher in the obesity and metabolic syndrome groups. No significant difference was found between the groups in terms of vitamin A, vitamin B6 and free carnitine levels. Significantly decreased vitamin E, vitamin B2, vitamin B12 and folic acid and increased vitamin B1 levels were observed in the obesity and metabolic syndrome groups. CONCLUSIONS: Compared to healthy children, children with obesity and metabolic syndrome may have varying degrees of micronutrient and vitamin deficiency due to poor and unbalanced eating habits. These deficiencies should also be considered in the treatment and follow-up of obesity and metabolic syndrome.