Oya Ercan

Homozygous Thyroid Hormone Receptor β-Gene Mutations in Resistance to Thyroid Hormone: Three New Cases and Review of the Literature

CONTEXT The most common cause of resistance to thyroid hormone (RTH) is heterozygous thyroid hormone receptor β (THRB) gene mutations. Homozygous mutations in the THRB gene are a rare event. OBJECTIVE In this study, the clinical findings of three new patients (belonging to two families) homozygous for mutations in the THRB gene are compared to three other families in which affected individuals lack a normal TRβ. METHODS We conducted clinical studies and genetic analyses. RESULTS The clinical presentation in all three homozygous subjects was unusually severe; their phenotype was characterized by compromised intellectual development, tachycardia, goiter, growth retardation, and hearing loss. This was comparable with one other reported patient homozygous for mutant TRβ, but not in RTH due to THRB gene deletions. CONCLUSION We report three new subjects, from two families, in whom RTH was associated with homozygous mutations in the THRB gene. They represent an important addition to the single known patient homozygous for a mutant TRβ. The clinical and laboratory abnormalities indicate a strong dominant-negative effect and are in agreement with data obtained from mice expressing a mutant Thrb in both alleles. This report strengthens the concept that the mutated TRβ interferes with the function of the TRα1 in humans.

Trends in overweight prevalence among 11-, 13- and 15-year-olds in 25 countries in Europe, Canada and USA from 2002 to 2010

BACKGROUND The purpose of this study was to assess recent changes in the prevalence of overweight (including obesity) among 11-, 13- and 15-year-olds in 33 countries from 2002 to 2010. METHODS Data from 25 countries from three consecutive survey cycles (2002, 2006 and 2010) that had at least 80% response rate for self-reported height, weight and age were analysed using logistic regression analysis. RESULTS Overweight prevalence increased among boys in 13 countries and among girls in 12 countries; in 10 countries, predominantly in Eastern Europe, an increase was observed for both boys and girls. Stabilization in overweight rates was noted in the remaining countries; none of the countries exhibited a decrease over the 8-year period examined. In the majority of countries (20/25) there were no age differences in trends in overweight prevalence. CONCLUSION In over half of the countries examined overweight prevalence did not change during 2002-2010. However, increasing overweight prevalence was noted in many Eastern European countries over this time period. Overweight prevalence remained high in several countries in Europe and North America. These patterns call for continued research in youth overweight and highlight the need to understand cross-national differences by examining macro-level indicators. Such research should feed into developing sound translations and practices to prevent and reduce overweight in youth.

Evaluation of glucose intolerance in adolescents relative to adults with type 2 diabetes mellitus.

AIM There is an increasing trend in the prevalence of type 2 diabetes mellitus (DM2) in childhood and adolescence, while positive family history of DM2 and obesity are the most important risk factors. To study the influence of family history and obesity on glucose intolerance in our country was the aim of this study. STUDY DESIGN AND METHODS A total of 105 children and adolescents aged 10-18 years (mean 13.3 +/- 2.5 years) were included in the study. All children and adolescents were divided into three groups according to positive family history of DM2 and obesity, and an oral glucose tolerance test (OGTT) was performed for all. Prediabetes was defined as impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG). Insulin secretion and insulin resistance were estimated using the insulinogenic index; and the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda index, respectively. RESULTS The prevalence of prediabetes was 15.2% in the whole group, while it was 25.5% in obese children who also had a positive family history of DM2. The frequency of hyperinsulinism was 57.1% in all groups. Prediabetic children had significant insulin resistance (HOMA-IR 11.5 +/- 7.1 and 4.1 +/- 6.4, respectively, p = 0.034). CONCLUSIONS Obesity and glucose intolerance are also a problem in developing countries. The risk of prediabetes in children is highest in obese children who also have a positive family history of DM2. There is a need for a lifelong preventive program starting in childhood to avoid DM2 and decrease cardiovascular risk factors

The Role of Parental, School, and Peer Factors in Adolescent Bullying Involvement: Results From the Turkish HBSC 2005/2006 Study

The aim of this study was to explore the relationships between involvement in bullying behaviors and school, family, and peer factors. Health Behavior in School Age Children survey questionnaire was used. Of the students surveyed, 20% were both bully and victim, 11% were bully, and 21% were victim. Being male, poor parental support, and poor monitoring by the father were found to be risk factors for being both bully and victim. Poor academic achievement, having peers at different ages, poor quality of friendship, poor communication with parents, and not being isolated by peers were found to be risk factors for being bully. Not liking school, feeling pressured by school work, poor quality of friendship, poor monitoring by the father, close bonding with mother, and poor status of the peer group were found to be risk factors for being victim. These findings highlight the importance that bullying intervention programs should include country-specific and culture-specific influences for success.

The role of leptin, soluble leptin receptor, resistin, and insulin secretory dynamics in the pathogenesis of hypothalamic obesity in children.

IntroductionIn this study, we have investigated the role of leptin, soluble leptin receptor(sOb-R), resistin, and insulin secretory dynamics in the development of hypothalamic obesity.Materials and methodsChildren who had hypothalamo-pituitary tumor were divided into two groups. First group included obese-overweight (hypothalamic obese = HOB group, n = 23) and second group included non-obese children (hypothalamic non-obese = HNOB group, n = 16). Exogenously obese-overweight children (OB group, n = 22) were included as controls. Basal and second-hour serum glucose and insulin in oral glucose tolerance test (OGTT), basal serum leptin, sOb-R, resistin levels, and homeostasis model assessment (HOMA) indexes were compared between the groups.ResultsAge, sex, and pubertal status were similar in study groups. Median and interquartile ranges of body mass index (BMI) z scores were similar in HOB and OB groups (2.0 (1.5–2.1) and 2.1 (1.8–2.3), respectively). Serum leptin levels corrected for BMI were highest and total leptin/sOb-R ratios (free leptin index (FLI)) tended to be higher in HOB than HNOB and OB groups, indicating leptin resistance (leptin/BMI, 4.0 (1.6–5.2), 1.5 (0.8–3.1), and 2.5 (1.8–3.5); FLI, 2.0 (0.8–3.5), 0.6 (0.3–1.2), and 1.5 (1–2.3) in HOB, HNOB, and OB groups; respectively). Serum resistin levels were similar in groups (2.6 (1.9–3.1), 2.8 (1.7–3.4), and 3.0 (2.2–3.5) ng/ml in HOB, HNOB, and OB groups, respectively). Basal serum glucose, basal and second-hour insulin levels in OGTT, and HOMA index were higher in OB group than the HOB and HNOB groups, indicating insulin resistance in simple obesity; however, increment of insulin to same glycemic load in OGTT was highest in the HOB group indicating insulin dysregulation (p < 0.05).ConclusionHypothalamic obesity seems to be related to both dysregulated afferent (leptin) and efferent (insulin) neural outputs through the autonomic nervous system resulting in energy storage as fat.

Hypospadias in Istanbul: Incidence and risk factors

Background:  The aim of the present prospective study was to determine the incidence of hypospadias in newborns in one of the busiest teaching hospitals of Istanbul, and to investigate the risk factors.

Prevalence and risk factors of iodine deficiency among schoolchildren.

The aim of this study was to demonstrate the prevalence of iodine deficiency among schoolchildren and the risk factors influencing it. One thousand five hundred and seventy-three schoolchildren were chosen from 14 schools in seven different regions in Istanbul. After all data relating to sociodemographic factors and the use of iodized salt were recorded, iodine contents of urine samples were determined by the Sandell Kolthoff reaction. Chi-squared and multiple regression analysis were used for the investigation of the correlation between iodine deficiency and risk factors. The prevalence of goitre (> or = 2 grade) was 1.9 per cent. The median urine iodine level was in the normal range (10.5 microg/dl). In 46.2 per cent of the students the urine iodine levels were below 10 microg/dl and 13.9 per cent of the students had urine iodine levels below 5 microg/dl. The prevalence of iodine deficiency was significantly higher in younger (< or = 10 years) children, in children with less educated mothers and fathers, and with poorer and more crowded families (p < 0.01, p < 0.01 and p < 0.01, p < 0.001, respectively). The rate of iodine deficiency was significantly higher in females than in males and also higher in children who lived on the European side of Istanbul than on the Anatolian side of Istanbul (p < 0.0001, p < 0.0001, respectively). The rate of use of iodized salt was 44.4 per cent and the iodine deficiency rate was not affected by the use of iodized salt (p > 0.05). Although the median urine iodine level was in the normal range, in 46.2 per cent of the students urine iodine levels were low (< 10 microg/dl). As there seems to be no effect from the use of iodized salt in iodine deficiency, the use of a more stable potassium iodate for the fortification of salt may be required.

Vitamin D Deficiency and Hashimoto’s Thyroiditis in Children and Adolescents: a Critical Vitamin D Level for This Association?

Objective: Vitamin D has been suggested to be active as an immunomodulator in autoimmune diseases such as Hashimoto’s thyroiditis (HT). The goal of the present study was to investigate the vitamin D status in HT patients. Methods: This prevalence case-control study was conducted on 90 patients with HT (of ages 12.32±2.87 years) and 79 age-matched healthy controls (11.85±2.28 years). Serum 25-hydroxyvitamin D3 [25(OH)D3] levels were measured in all 169 subjects. Results: The prevalence of vitamin D deficiency in HT patients (64 of 90; 71.1%) was significantly higher than that in the control group (41 of 79; 51.9%) (p=0.025). Mean serum 25(OH)D3 level in the HT group was significantly lower compared to the control group (16.67±11.65 vs. 20.99±9.86 ng/mL, p=0.001). HT was observed 2.28 times more frequently in individuals with 25(OH)D3 levels <20 ng/mL (OR: 2.28, CI: 1.21-4.3). Conclusion: Vitamin D deficiency is associated with HT in children and adolescents. Levels lower than 20 ng/mL seem to be critical. The mechanism for this association is not clear.

Subclinical hypothyroidism in in vitro fertilization babies.

Aim:  Assisted reproduction technology is used widely all over the world. There is a great concern about the morbidity of in vitro fertilization (IVF) babies, but investigations are mostly related to mechanical conditions that are attributed to multiparity. This paper aimed to investigate the effect of IVF on thyroid functions in newborns.

Gender Identity and Gender Role in DSD Patients Raised as Females: A Preliminary Outcome Study

Gender identity and gender role are expected to be consistent with gender assignment for optimal DSD management outcome. To our knowledge, our study is the first to attempt evaluation of gender related outcomes in Turkish DSD patients. After receiving institutional ethical board approval and subject (or parent) informed consent, subjects with DSD raised as girls (22 patients 46 XX DSD, 11 patients 46 XY DSD) answered 566 questions of the Minnesota Multiphasic Personality Inventory (MMPI) questionnaire including 60-item Masculinity-Femininity (MF) subscale which was the focus in this study. Controls (n: 50) were females similar to the probands in age, level of education, relationship status, and having a job or not also answered all questions. The answers were evaluated by a trained psychologist (Derya Inceoglu) on MMPI. For statistical purposes, seven findings were obtained from the data related to the MF subscale from the patients and controls. Of these seven findings (S1–S7), two were associated with masculinity (S3–S4) and another two were associated with femininity (S5–S6). In DSD patients, the percentages of masculinity findings were significantly higher when compared to controls (p < 0.001 and p < 0.001 for S3 and S4, respectively). In controls, the percentages of femininity findings were significantly higher when compared to DSD females (p < 0.001 and p < 0.001 for S5 and S6 respectively). There was no significant difference between 46 XX DSD patients and 46 XY DSD patients with respect to the percentage of any of the seven findings. Two patients requested gender change to male; only these two patients had the finding stating that sexual impulses could come to existence as actions (S7). In conclusion efforts to identify modifiable factors with negative impact and thus modifying them, and professional guidance may be important in minimizing the encountered gender related problems in DSD patients.