Il Tae Hwang

Low Vitamin D Levels Are Associated with Both Iron Deficiency and Anemia in Children and Adolescents

Background: We aimed to examine the association between vitamin D deficiency and anemia in a nationally representative sample of Korean children and adolescents. Methods: Cross-sectional data on 2526 children and adolescents aged 10–20 years from the Korea National Health and Nutrition Examination Survey-V (2010–2012) were used. Anemia was defined according to specifications of the World Health Organization. Iron deficiency was defined as serum ferritin level of <12 ng/mL and transferrin saturation (TSAT) <16%. Results: The prevalence of vitamin D deficiency in Korean children and adolescents was high especially in female (35.7% vs. 50.9%, P < 0.001). The prevalence of anemia was also higher in female (1.1% vs. 6.8%; P < 0.001). In logistic regression, risk factors for anemia were female sex, old age, post-menarche, low household income, vitamin D deficiency, and iron deficiency. The Odds Ratio for anemia, iron deficiency and iron deficiency anemia (IDA) in subjects with vitamin D deficiency (<15 ng/mL) were 1.81(95% CI, 1.13–2.88), 1.94(95% CI, 1.27–2.97), and 2.26 (95% CI, 1.20–4.24) after controlling for other risk factors. However, after examining the sexes separately, only female subjects showed statistical significance. After further controlling for iron deficiency, the risk of anemia was not significant (P = 0.261). Conclusions: Vitamin D deficiency is associated with increased risk of anemia, especially iron deficiency anemia, in healthy female children and adolescents. However, the association is attenuated after adjustment for iron deficiency. Further studies are needed to determine whether vitamin D deficiency is the cause of anemia, or bystander of nutritional deficiency which cause iron deficiency.

Reference values for serum levels of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in Korean children and adolescents.

OBJECTIVEnMeasurements of serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) are utilized in the diagnostic work-up and clinical management of children with growth disorders. We designed this study to establish the reference values of serum IGF-I and IGFBP-3 levels according to age, sex and pubertal stage in Korean children and adolescents.nnnMETHODSnFor the study, 1378 healthy Korean children and adolescents aged 0 to 17 years (722 boys, 656 girls) were randomly selected. Blood samples were collected, and the stored sera were assayed for IGF-I and IGFBP-3 using immunoradiometric assay (IRMA, Immunotech). The R 2.8.1 program (Bell Laboratories) was used to generate reference percentile curves for IGF-I and IGFBP-3 according to age, sex, and pubertal stagennnRESULTSnSerum IGFBP-3 level was higher in girls compared to that in boys of the same ages throughout the pubertal period, whereas IGF-I was only higher for girls younger than 13 years of age. Serum levels of IGF-I and IGFBP-3 increased steadily with age in the prepubertal stage, followed by a progressive decline thereafter. Peak levels of serum IGF-I and IGFBP-3 were observed two years earlier in girls compared to those in boys (13 vs. 15 years of age, respectively). Serum IGF-I and IGFBP-3 concentrations were highest at Tanner stage IV in boys and girls, with a subsequent decline.nnnCONCLUSIONSnOur reference value model based on age, sex, and pubertal stage can improve the diagnostic utility of IGF-1 and IGFBP-3 levels in the evaluation and management of Korean children and adolescents with growth disorders.

The effect of gonadotrophin‐releasing hormone agonist treatment over 3 years on bone mineral density and body composition in girls with central precocious puberty

Puberty is a period characterized by growth spurt and rapid change in body composition. The effect of GnRH agonist therapy for central precocious puberty on bone mineral density is unclear. We demonstrated changes in bone mineral density in subjects with central precocious puberty, who were treated with GnRH agonist for more than 3 years.

New Korean reference for birth weight by gestational age and sex: data from the Korean Statistical Information Service (2008-2012)

Purpose To construct new Korean reference curves for birth weight by sex and gestational age using contemporary Korean birth weight data and to compare them with the Lubchenco and the 2010 United States (US) intrauterine growth curves. Methods Data of 2,336,727 newborns by the Korean Statistical Information Service (2008-2012) were used. Smoothed percentile curves were created by the Lambda Mu Sigma method using subsample of singleton. The new Korean reference curves were compared with the Lubchenco and the 2010 US intrauterine growth curves. Results Reference of the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles birth weight by gestational age were made using 2,249,804 (male, 1,159,070) singleton newborns with gestational age 23-43 weeks. Separate birth weight curves were constructed for male and female. The Korean reference curves are similar to the 2010 US intrauterine growth curves. However, the cutoff values for small for gestational age (<10th percentile) of the new Korean curves differed from those of the Lubchenco curves for each gestational age. The Lubchenco curves underestimated the percentage of infants who were born small for gestational age. Conclusion The new Korean reference curves for birth weight show a different pattern from the Lubchenco curves, which were made from white neonates more than 60 years ago. Further research on short-term and long-term health outcomes of small for gestational age babies based on the new Korean reference data is needed.

Hypoparathyroidism, sensorineural deafness, and renal dysgenesis syndrome with a GATA3 mutation

Hypoparathyroidism, sensorineural deafness, and renal dysgenesis syndrome is an autosomal dominant disease caused by mutations in the GATA3 gene on chromosome 10p15. We identified a patient diagnosed with hypoparathyroidism who also had a family history of hypoparathyroidism and sensorineural deafness, present in the father. The patient was subsequently diagnosed and found to be a heterozygote for an insertion mutation c.255_256ins4 (GTGC) in exon 2 of GATA3. His father was also confirmed to have the same mutation in GATA3.

Clinical and radiological findings of incidental Rathke's cleft cysts in children and adolescents

Purpose In the pediatric population, Rathkes cleft cysts (RCCs) are known to be an infrequent cause of headaches, visual disturbances, and pituitary dysfunction. We investigated the clinical characteristics of children in whom RCCs were incidentally discovered and evaluated whether RCCs influence the treatment response of patients with proven endocrinopathy. Methods A retrospective analysis was conducted in 34 patients with RCCs who were diagnosed between 2006 and 2013 at Hallym University Medical Center. Their clinical, hormonal, and imaging findings were reviewed. We evaluated the clinical outcomes of the patients with concomitant RCCs and endocrinopathy compared to matched controls. Results Twenty-six of 34 patients with radiologically proven RCCs had endocrine disorders. They were 9 boys and 17 girls, with ages ranging from 4.8 to 17.4 years at the time of the diagnosis. Of these, 7 (27%) had idiopathic short stature, 7 (27%) had growth hormone deficiency (GHD), and 12 (46%) had central precocious puberty (CPP). Nineteen of 26 patients (73.1%) showed low signal intensities on T1-weighted images (T1WI) and high signal intensities on T2-weighted images. The incidence of hypointensity on T1WI was higher in the patients with RCCs accompanied by endocrinopathy than in those without endocrinopathy (P=0.033). The treatment outcomes of the patients with CPP and GHD with and without RCCs were similar. Conclusion CPP and GHD patients with a small RCC (less than 20 mm) expressing cystic magnetic resonance intensity can be managed with medical treatment, although the RCCs need to be closely monitored in radiological studies to observe their growth.

Response to three years of growth hormone therapy in girls with Turner syndrome

Purpose Short stature is the most common finding in patients with Turner syndrome. Improving the final adult height in these patients is a challenge both for the patients and physicians. We investigated the clinical response of patients to growth hormone treatment for height improvement over the period of three years. Methods Review of medical records from 27 patients with Turner syndrome treated with recombinant human growth hormone for more than 3 years was done. Differences in the changes of height standard deviation scores according to karyotype were measured and factors influencing the height changes were analyzed. Results The response to recombinant human growth hormone was an increase in the height of the subjects to a mean value of 1.1 standard deviation for subjects with Turner syndrome at the end of the 3-year treatment. The height increment in the first year was highest. The height standard deviation score in the third year was negatively correlated with the age at the beginning of the recombinant human growth hormone treatment. Different karyotypes in subjects did not seem to affect the height changes. Conclusion Early growth hormone administration in subjects with Turner syndrome is helpful to improve height response to the treatment.

Irisin is a biomarker for metabolic syndrome in prepubertal children

The aim of the present study was to evaluate the association of irisin with obesity and metabolic syndrome (MetS) in Korean prepubertal children. A total of 96 children and adolescents aged 6 to 10 years (56 males) were included in this study. Subjects were divided into 3 groups: normal weight (n = 54), overweight (n = 16), and obese (n = 26). In the subgroup analyses, overweight/obese children were further divided based on their MetS status (with MetS vs. without MetS). Children with obesity tended to exhibit a lower mean irisin concentration compared to those with normal weight (p = 0.028). Using Pearsons correlation coefficient to compare all the children in the study, there was a significant inverse correlation between irisin and body mass index (BMI) standard deviation scores (SDS) (r = -0.210, p = 0.041), waist circumference SDS (r = -0.203, p = 0.049), and glucose (r = -0.296, p = 0.004). In the subgroup analyses of overweight/obese children, irisin exhibited a significant inverse correlation with glucose (r = -0.507, p = 0.001) and triglycerides (r = -0.331, p = 0.033). Children with MetS exhibited lower irisin concentrations than those without MetS (14.70 ng/mL vs. 22.02 ng/mL, p = 0.001), and these associations were significant after adjusting for age, gender, and BMI SDS (14.51 ng/mL vs. 22.06 ng/mL, p = 0.002). The irisin level of 15.43 ng/mL was determined to be a possible cutoff to distinguish children with metabolic syndrome from overweight/obese children, with a sensitivity of 75% and a specificity of 94% (p < 0.001). Our results suggest that decreased irisin levels may be associated with MetS in prepubertal children and that irisin might be a biomarker for MetS in prepubertal children.

Efficacy and safety of growth hormone treatment for children born small for gestational age

Recombinant growth hormone (GH) is an effective treatment for short children who are born small for gestational age (SGA). Short children born SGA who fail to demonstrate catch-up growth by 2-4 years of age are candidates for GH treatment initiated to achieve catch-up growth to a normal height in early childhood, maintain a normal height gain throughout childhood, and achieve an adult height within the normal target range. GH treatment at a dose of 35-70 µg/kg/day should be considered for those with very marked growth retardation, as these patients require rapid catch-up growth. Factors associated with response to GH treatment during the initial 2-3 years of therapy include age and height standard deviation scores at the start of therapy, midparental height, and GH dose. Adverse events due to GH treatment are no more common in the SGA population than in other conditions treated with GH. Early surveillance in growth clinics is strongly recommended for children born SGA who have not caught up. Although high dose of up to 0.067 mg/kg/day are relatively safe for short children with growth failure, clinicians need to remain aware of long-term mortality and morbidity after GH treatment.

Multicenter clinical trial of leuprolide acetate depot (Luphere depot 3.75 mg) for efficacy and safety in girls with central precocious puberty

Purpose We evaluated the efficacy, safety and psychological aspect of monthly administrations of the gonadotropin-releasing hormone agonists (GnRHa), leuprolide acetate depot (Luphere depot 3.75 mg), in patients with precocious puberty. Methods A total of 54 girls with central precocious puberty were administered with leuprolide acetate (Luphere depot 3.75 mg) every four weeks over 24 weeks. We evaluated the percentage of children exhibiting a suppressed luteinizing hormone (LH) response to GnRH (LH peak≤3 IU/L), peak LH/follicle stimulating hormone (FSH) ratio of GnRH stimulation test less than 1, change in bone age/chronologic age ratio, change in the Tanner stage and change in eating habit and psychological aspect. Results (1) The percentage of children exhibiting a suppressed LH response to GnRH, defined as an LH peak≤3 IU/L at 24 weeks was 96.3 % (52/54). (2) The percentage of children exhibiting peak LH/FSH ratio<1 at 24 weeks of the study was 94.4 % (51/54). (3) The ratio of bone age and chronological age significantly declined from 1.27±0.07 to 1.24±0.01 after the 6 months of the study. (4) The mean Tanner stage manifested a significant change 2.3±0.48 at baseline, down to 1.70±0.61 at 24 weeks. (5) Based on the questionnaires, the score for eating habits showed a significant change from the baseline 34.0±6.8 to 31.3±6.8. (6) The psychological assessment did not exhibit a significant difference except with scores for sociability, problem behavior total score and other problems. Conclusion The leuprolide 3.75 mg (Luphere depot) is useful and safety for treating children with central precocious puberty.