Volume 30, Issue 2

Background: As a result of the rising prevalence of childhood obesity, there is an increasing interest in the type 2 diabetes mellitus precursor insulin resistance (IR). The aim of this study is to review definitions (methods and cutoff values) to define IR in children and to apply these definitions to a previously described obese pediatric population. Methods: A systematic literature review on prevalence and/or incidence rates in children was performed. The extracted definitions were applied to an obese pediatric population. Results: In the 103 identified articles, 146 IR definitions were reported based on 14 different methods. Fasted definitions were used 137 times, whereas oral/intravenous glucose tolerance test-derived methods were used nine times. The homeostasis model for the assessment of insulin resistance (HOMA-IR) and fasted plasma insulin (FPI) were the most frequently used fasted methods (83 and 37 times, respectively). A wide range in cutoff values to define IR was observed, resulting in prevalence rates in the predefined obese pediatric population between 5.5% (FPI>30 mU/L) and 72.3% (insulin sensitivity index Matsuda ≤7.2). Conclusions: To compare IR incidence and prevalence rates in pediatric populations, a uniform definition of IR should be defined.

Background: Food allergy in childhood is on the rise globally and is managed with avoidance diets; recent case reports of food allergic children with nutritional rickets in the literature highlight the importance of close monitoring of bone health in this population. Methods: There is no consensus as yet with regard to bone health evaluation in food allergic children; therefore, extensive literature search was performed and the existing evidence is presented, along with a relevant algorithm. Results: Children allergic to cow’s milk protein or presenting with allergy in more than three food items, as well as patients with severe allergic phenotypes or comorbidities known to affect the skeleton, seem to be at risk of metabolic bone disorders. As a practical guide, suspicious cases can be investigated with basic bone profile, whereas more severe cases (persistent bone pain and fractures) may undergo advanced bone health assessment, with bone mineral density (BMD) and metabolic bone markers’ evaluation. Of note, these diagnostic steps call for further studies in the field of food allergy, as they are not performed as a routine. Evidence is accumulating with regard to vitamin D deficiency, osteopenia and imbalanced bone metabolism in those food allergic children who show poor dietary compliance or have inadequate medical supervision. Conclusions: Ensuring optimal bone accrual in a food allergic child is an important task for the clinician and requires close monitoring of the restrictive diet and prompt therapeutic intervention, in an effort to avoid rickets or osteopenia.

Background: Animal models have shown that the skeletal hormone osteocalcin stimulates testicular testosterone synthesis. To assess whether osteocalcin might be a useful marker to detect pubertal development disorders, we examined osteocalcin plasma concentrations in children and adolescents with and without disorders of pubertal development. Methods: Osteocalcin concentrations were investigated in a total of 244 patients with endocrine disorders (122 males, mean age: 11.87+3.77 years), including patients with precocious puberty and constitutional delay of puberty. Results: Osteocalcin concentrations were highest among adolescents with precocious puberty and advanced pubertal development (120.60±45.22 ng/mL), while the concentrations were lowest among patients with constitutional delay of puberty (102.20±37.13 ng/mL). Overall, osteocalcin concentrations were strongly correlated with markers of bone metabolism. Conclusions: Although plasma osteocalcin concentrations are associated with pubertal development in boys, it does not appear to be a useful diagnostic marker for altered pubertal development.

Background: Congenital hypothyroidism (CH) is a common endocrine disease and an important cause of mental retardation. The purpose of this study was to investigate the probable role of season and climatic factors in the incidence of CH in Kerman province, Iran. Methods: Incidence data were collected from the CH screening program files from 2005 to 2011 in Kerman province, a number of 288,437 infants were included in the study. Climate data were collected from the Meteorological Office. The relations were tested by χ 2 -test, Pearson correlation, and negative binomial regression. Results: The overall incidence of CH in Kerman province was 2.68 per 1000 births. There was a significant difference in both the monthly and seasonal incidence of CH (p<0.05). There were a few significant, but weak correlation between some climatic factors and the incidence of CH in some regions, but the results were inconsistent. Conclusions: It seems like there is no clear relation between CH incidence and climate factors, in Kerman Province. However, CH incidence was highest in October (Autumn) and lowest in June (Summer).

Background: Endocrine evaluation and long-term follow-up of seven (six male) patients with Williams-Beuren syndrome (WBS) are given. Method: Data were obtained from patients’ medical records. All patients underwent hormonal analyses and four of them underwent oral glucose tolerance test (OGTT). Results: They all had mild hypercalcemia. Three of them had overt hypothyroidism while subclinical hypothyroidism was detected in three patients. Four patients had thyroid hypoplasia and one had thyroid agenesis. Growth hormone deficiency (GHD) was determined in one patient. Impaired glucose tolerance (IGT) was found in three adolescents. All adolescents had early-onset puberty. The follow-up duration was 5.7±2.1 years. The mean growth velocity (GV) was 12.9±7.2 cm and 7.6±2 cm at the end of the first and second years of therapy, respectively. All patients had neurodevelopment retardation and were continuing to special education. Conclusions: Thyroid hypoplasia is common and agenesis can be seen in patients with WBS; therefore, thyroid hormones should be measured in the newborn period and annually. GHD should be kept in mind in patients with decreased GV. IGT might be detected in patients with WBS even in adolescence.

Background: Obesity and hypertension (HT) are well known cardiac risk factors. Our goal was to show that even if arterial blood pressure (BP) measurements of obese adolescents are normal during clinical examination, ambulatory blood pressure monitoring (ABPM) can be high, may include cardiac involvement and can also detect left ventricular mass indices (LVMI) value for obese adolescents to diagnose left ventricular hypertrophy (LVH). Methods: This study included 130 children (57 obese hypertensive, 36 obese normotensive, 14 normal weight hypertensive and 23 normal weight normotensive). Adolescents whose BP was measured during clinical examination, after 24-h BP was detected using ABPM, were examined with echocardiography for calculation of LVMI to determine cardiac risk factors for LVH. Results: There was a significant difference between the LVMI of obese-normotensive and obese-hypertensive adolescents, which showed the effect of obesity on LVMI independent of HT. Twenty (35.7%) of 56 obese adolescents with HT detected with ABPM had normal BP measurements during clinical examination. Dipper and nondipper features of obese adolescents were significantly higher in ABPM than those with normal body mass index. When the cutoff LVMI value for LVH was set at ≥38 g/m 2.7 , 38.9% of obese-normotensive and 50.9% of obese-hypertensive subjects had LVH; however, when the cutoff value was set at ≥51 g/m 2.7 , the rates were 2.8% and 19.3%, respectively. Conclusions: Obesity is a risk factor for LVH independent of HT. To identify masked HT, 24-h ABPM and cardiac examination should be routinely performed in obese adolescents. Using a limit of LVMI ≥38 g/m 2.7 in evaluating LVH secondary to HT in obese individuals may lead to an overestimated diagnosis rate of LVH.

Background: Neurofibromatosis type 1 (NF1) is a multisystem disorder characterized by progressive manifestations, which is inherited in an autosomal dominant manner. The majority of patients with NF1 experience a diffuse, significant reduction in bone mass over time, with osteoporosis, osteopenia in the absence of severe scoliosis, or gross bone deformities. This study aimed to determine the bone mineral density (BMD) status, evaluate bone metabolism, and to determine the relevant factors in children with NF1. Methods: The study population included 33 pediatric NF1 patients (20 males and 13 females). Bone metabolic markers, such as total calcium, phosphorus, magnesium, alkaline phosphatase, parathyroid hormone, and 25-OH vitamin D, the urinary calcium/creatine ratio were measured. In addition, BMD was measured at both the lumbar spine (LS) and the femoral neck in all the patients. Results: All the patients had a low 25-OH vitamin D level, but it was significantly lower in the females than in the males (p<0.009). Overall, 18.2% of the patients had skeletal abnormalities. The lumbar Z-score was ≤2 in 21.2% of the patients, whereas the femoral neck Z-score was ≤2 in 9.1%. The urinary calcium/creatine ratio was significantly higher in the female than in the male patients (p<0.027). In all, six patients had skeletal abnormalities. Conclusions: It is widely known that bone mineral metabolism markers and BMD are significantly affected in NF1 patients; however, the present study did not identify any effective parameters that could be used to predict skeletal abnormalities, or diagnose early osteoporosis and osteopenia in pediatric NF1 patients.

Background: Dyslipidemia increases the frequency and severity of micro and macrovascular complications of type 1 diabetes (T1D). The present study aims to determine the prevalence of dyslipidemia and its association with clinical and laboratory findings in diabetic children and adolescents. Methods: The study included 202 children and adolescents with T1D. Demographic data and laboratory findings were obtained from patients files. Results: Dyslipidemia prevalence was found to be 26.2%. Hypercholesterolemia (15.8%) and hyperglyceridemia (12.9%) were most common findings. Age, body mass index (BMI), hemoglobin A 1c (A 1C ) and poor metabolic control were significantly higher in cases with dyslipidemia. Smoking rate was 14.1% in the pubertal group. Poor metabolic control and dyslipidemia was found higher among smokers (p<0.05). Conclusions: Blood lipid levels should be monitored regularly and nutrition education should be repeated periodically to prevent and control dyslipidemia in patients with T1D. Smoking-related risks should be a part of patient education in the pubertal period.

Background: There is debate on which overweight and obese children should be screened for the presence of impaired glucose tolerance (IGT) by oral glucose tolerance testing (OGTT). The objective of the study was to identify risk factors predictive of the presence of IGT. Methods: In a cohort of overweight children, who underwent OGTT, we determined the association of anthropometric and laboratory parameters with IGT and whether combining parameters improved the sensitivity of screening for IGT. Results: Out of 145 patients, IGT was present in 11, of whom two had impaired fasting glucose (IFG). Elevated blood pressure (p=0.025) and elevated liver enzymes (p=0.003) were associated with IGT, whereas IFG was not (p=0.067), screening patients with either one of these parameters predicted IGT with a high sensitivity of 1.00, and a number needed to screen of 5.7. Conclusions: Screening all patients with either IFG, presence of elevated blood pressure and elevated liver enzymes, significantly increases predictability of IGT compared to using IFG alone.

Background: In recent years, several studies have been published showing different responses to growth hormone (GH) treatment in idiopathic short stature children. The aim of the present study was to investigate whether non-growth-hormone-deficient (non-GHD) short children could benefit from long-term GH treatment as GHD patients. Methods: We enrolled 22 prepubertal children and 22 age- and sex-matched GHD patients, with comparable height, body mass index (BMI), bone age, and insulin-like growth factor 1 (IGF-I) circulating levels. The patients were treated with recombinant human GH (rhGH) and followed until they reach adult height. Results: During GH treatment, the two groups grew in parallel, reaching the same final height-standard deviation score (SDS) and the same height gain. On the contrary, we found significantly lower IGF-I serum concentrations in non-GHD patients than in GHD ones, at the end of therapy (p=0.0055). Conclusions: In our study, the response to GH treatment in short non-GHD patients proved to be similar to that in GHD ones. However, a careful selection of short non-GHD children to be treated with GH would better justify the cost of long-term GH therapy.

Background: Obesity among children and adolescents is a growing public health problem. The objective of this study was to evaluate the prevalence, risk factors and metabolic consequences of obesity among schoolchildren from Kashmir, India. Methods: The study subjects (n=2024) included 870 boys and 1154 girls, aged between 6 and 18 years. Data were collected by interviewer-administered questionnaires. Information was obtained about different lifestyles, anthropometric parameters and dietary habits. Obesity was defined as body mass index (BMI) percentile as per the guidelines of Centers for Disease Control, 2000. For the evaluation of different clinical parameters, blood samples were collected from the subjects in the fasting state at 8 to 9 am after an overnight (10–12 h) fast. Results: The highest representation of subjects was from fee-paying private schools. Out of the total subjects, 6.69% were overweight and 4.64% were obese. The hip circumference, abdominal circumference, BMI, blood pressure (BP), use of ready-made foods as well as the clinical parameters like glucose, phosphorous, cholesterol and triglycerides were found significantly higher among girls than boys (p<0.05). Boys were taller and were physically more active than girls (p<0.01). Compared to the boys (3.33%), the girls were found to be more obese (5.63%). Rural dwelling subjects (4.22%) exhibited a lower percentage of obesity than urban population (5.00%). The difference in obesity among the different age groups was found statistically significant (p<0.05). Additionally, children with active lives in the form of vigorous (10.59%) or moderate (10.34%) exercise decreased their chances of gaining weight substantially. Conclusions: Results from the present study have shown that prevalence of obesity among children was high in our population.

Background: The relationship between screen time (ST) and the frequency of snack consumption in a national sample of Iranian children and adolescents was assessed. The present nationwide survey was conducted on 14,880 school students living in urban and rural areas of 30 provinces in Iran. Trained healthcare providers conducted the physical examination and completed the questionnaire of the World Health Organization – Global School-Based Student Health Survey (WHO-GSHS). Methods: The association between ST (total time spent watching TV and using a computer in leisure time) and the frequency of snack consumption was determined using ordinal logistic regression analysis. The subjects were 13,486 students out of the 14,880 invited including 50.8% boys. The mean (SD) age of participants was 12.47 (3.36) years. Results: In multivariate models, for students who had prolonged ST (more than 4 h/day), the odds of daily consumption of sweets (odds ratio, OR 1.25; 95% CI 1.14–1.4), salty snacks (OR 1.6; 95% CI 1.5–1.76), soft drinks (OR 1.52; 95% CI 1.4–1.7), canned fruit juice (OR 1.3; 95% CI 1.2–1.4), and fast food (OR 1.53; 95% CI 1.4–1.7) were higher compared to those with low ST. Furthermore, the odds of daily consumption of milk in students who had prolonged ST (more than 4 h/day) were lower compared to those with low ST (OR 0.9; 95% CI 0.8–0.99). Conclusions: Prolonged time spent watching TV and using a computer during leisure time might be associated with unhealthy dietary habits. Moreover, inactivity induced by prolonged ST may also lead to unhealthy dietary habits and in turn excess weight in children and adolescents.

Background: Growth hormone (GH) transduction defect (GHTD) is a growth disorder with impaired signal transducer and activator of transcription 3 (STAT3) phosphorylation mediated by overexpression of cytokine-inducible SH2-containing protein (CIS), which causes increased growth hormone receptor (GHR) degradation. This study investigated the role of epidermal growth factor (EGF) in the restoration of normal GH signaling in GHTD. Methods: Protein expression, cellular localization and physical contact of proteins of the GH and EGF signaling pathways were studied by Western immunoblotting, immunofluorescence and co-immunoprecipitation, respectively. These were performed in fibroblasts of one GHTD patient (P) and one control child (C) at the basal state and after induction with human GH (hGH) 200 μg/L (GH200), either with or without silencing of CIS mRNA, and after induction with hGH 1000 μg/L (GH1000) or 50 ng/mL EGF. Results: The membrane availability of the EGF receptor (EGFR) and the activated EGFR (pEGFR) was increased in P only after simultaneous GH200 and silencing of CIS mRNA or with GH1000, whereas this occurred in C after GH200 alone. After EGF induction, the membrane localization of GHR, STAT3 and that of EGFR were increased in P more than in C. Conclusions: In conclusion, in GHTD, the EGFR seems to participate in successful GH signaling, but induction of GHTD fibroblasts with a higher dose of hGH is needed. The EGF/EGFR pathway, in contrast to the GH/GHR pathway, seems to function normally in P and is more primed compared to C. The involvement of the EGFR in successful GH signaling may explain the catch-up growth seen in the Ps when exogenous hGH is administered.

Background: Turner syndrome (TS) is the most common sex chromosome abnormality in females, typically associated with primary amenorrhea and premature ovarian failure due to gonadal dysgenesis. The association of TS with hypopituitarism is an uncommon finding. The objective of the study was to describe an adolescent with TS with hypergonadotropic hypogonadism and subsequent hypogonadotropic hypogonadism. Case presentation: A 16-year-old female with primary amenorrhea was diagnosed with TS based on karyotype 45,XO. Other laboratory values included FSH 45.52 IU/L, LH 17.4 IU/L, undetectable estradiol, and prolactin 1.08 nmol/L. Two months later and before treatment, she presented with severe headache and a new left cranial nerve VI palsy. Brain MRI showed a 2.7-cm hemorrhagic pituitary macroadenoma expanding the sella. Laboratory evaluation showed FSH 5.9 IU/L, LH 0.9 IU/L, prolactin 0.09 nmol/L, and GH 1.03 ng/mL. She underwent transphenoidal hypophysectomy, and pathology revealed pituitary adenoma with immunohistochemical staining positive for growth hormone and prolactin. She subsequently developed multiple pituitary hormone deficiencies. Review of the literature identified eight case reports of women with TS who developed pituitary adenomas. Conclusions: This case illustrates an uncommon co-occurrence of TS and pituitary macroadenoma. Sequential gonadotropin measurements demonstrate the evolution of hypergonadotropic hypogonadism into hypogonadotropic hypogonadism due to hemorrhagic pituitary macroadenoma.

Carnitine palmitoyltransferase II (CPT-II) deficiency is an autosomal recessively inherited disorder involving the β-oxidation of long-chain fatty acids, which leads to rhabdomyolysis and subsequent acute renal failure. The clinical phenotype varies from a severe infantile form to a milder muscle form. Here, we report a 9-year-old boy referred to our hospital for the investigation of hematuria with a 2-day history of dark urine and malaise. As no erythrocytes in the microscopic examination of the urine and hemoglobinuria were present, myoglobinuria due to rhabdomyolysis was the most probable cause of dark urine. After excluding the other causes of rhabdomyolysis, with the help of metabolic investigations, the patient was suspected to have CPT-II deficiency, the most common cause of metabolic rhabdomyolysis. Our aim in presenting this case is to emphasize considering rhabdomyolysis in the differential diagnosis of dark urine in order to prevent recurrent rhabdomyolysis and renal injury.

Three siblings with thiamine-responsive megaloblastic anemia (TRMA) with a homozygous c.454delGGCATinsAT mutation in SLC19A2 are described. The index case presented at 14 months’ old with severe non-ketotic hyperglycemia, dehydration, seizures and sinovenous thrombosis. She was started on insulin and developed sensorineural hearing loss around 2 years old. Two siblings were found to have the same mutation and were started on thiamine. One sibling developed transient hyperglycemia after several years of thiamine supplementation of 12 mg/kg that resolved with an increased thiamine dose (23 mg/kg). A younger sibling continues to remain diabetes-free on thiamine (24 mg/kg). The clinical course in this family suggests that there is an effect of thiamine on pancreatic beta cell function in patients with TRMA given the resolution of impaired fasting glucose with increasing thiamine dose in one sibling and the lack of diabetes to date in the siblings that were treated early with thiamine.

Background: Glycogen storage disease (GSD) type IX and growth hormone (GH) deficiency cause ketotic hypoglycemia via different mechanisms and are not known to be associated. We describe a patient presenting with severe ketotic hypoglycemia found to have both GSD IX and isolated GH deficiency. Case presentation: A 3-year-and-11-month-old boy with a history of prematurity, autism, developmental delay, seizures, and feeding difficulty was admitted for poor weight gain and symptomatic hypoglycemia. He was nondysmorphic, with a height of 93.8 cm (2%, –1.97 SDS), and has no hepatomegaly. He developed symptomatic hypoglycemia, with a serum glucose level of 37 mg/dL after 14 h of fasting challenge. Critical sample showed a GH of 0.24 ng/mL. GH provocative stimulation testing was done with a peak GH of 2.8 ng/mL. Brain magnetic resonance imaging showed a hypoplastic pituitary gland. Given the clinical symptoms, suspicion for mitochondrial disease was high. Dual Genome Panel by Massively Parallel Sequencing revealed a hemizygous variant c.721A>G (p1241V) in the X-linked PHKA2 gene, a causative gene for GSD IX. Red blood cell PhK enzyme activity testing was low, supporting the diagnosis. Conclusions: Given the patient’s developmental delays that were not explained by GH deficiency alone, further investigation showed two unrelated conditions resulting in deranged metabolic adaptation to fasting leading to severe hypoglycemia.