Isabel Dinis

Metabolic factors in obesity.

UNLABELLED Obesity has a rising prevalence in children and adolescents, affecting 30% of the paediatric population in Portugal. Leptin is an important hormone involved in the pathogenesis of obesity and has been under investigation as a risk marker for future complications. AIMS 1. To evaluate the relation between serum leptin levels and body mass index (BMI) and height. 2. To compare leptin levels in obese and non-obese children. 3. To evaluate the relation between leptin levels and insulin resistance index. METHODS Cross-sectional study, using a sample of 70 obese children and a control group of 53 non-obese children. Obesity was defined as BMI standard deviation > 2 for age and sex. In the obese group we assessed sex, age, BMI SDS and height SDS for age and sex, and serum levels of glucose, insulin and leptin. In the control group were obtained BMI SDS and height SDS for age and sex and leptin levels. Data were analysed using SPSS 12. RESULTS The mean age of obese and non-obese children was 10.3 +/- 2.9 versus 10.9 +/- 3.5 years. In the obese group, 32 (45.7%) were boys versus 18 (31.0%) in the non-obese group. BMI SDS in the obese group was 3.12 +/- 0.60 versus 0.20 +/- 0.99 in the non-obese group (p < 0.001). Leptin levels showed a positive correlation with BMI SDS (r = 0.69; p < 0.001) and height SDS (r = 0.31; p < 0.001). When comparing leptin levels between obese and non-obese groups, we found a significant difference in boys (50.7 +/- 27.3 versus 7.0 +/- 6.8 ng/ml; p < 0.001) and in girls (57.6 +/- 25.5 versus 16.5 +/- 10.3 ng/ml; p < 0.001). In the nonobese group, leptin levels were lower in boys. This difference was not seen in the obese group. Leptin showed a positive correlation with insulin resistance index in boys (r = 0.45, p = 0.05), but not in girls. CONCLUSIONS This study has confirmed a positive correlation between leptin levels and BMI SDS. In obese children elevated leptin is associated with central resistance to its action. The positive correlation of leptin with insulin resistance index may suggest a major role of leptin in insulin resistance.

Type 1 diabetes and GAD65 limbic encephalitis: a case report of a 10-year-old girl.

Abstract Limbic encephalitis is a rare neurological disorder that may be difficult to recognize. Clinical features include memory impairment, temporal lobe seizures and affective disturbance. We report the case of a 10-year-old girl with type 1 diabetes mellitus that presented with seizures, depressed mood and memory changes. The diagnosis of glutamic acid decarboxylase 65 (GAD65) mediated limbic encephalitis relied on cerebral magnetic resonance imaging lesions and high serological and cerebrospinal fluid GAD65-antibodies titers. High-dose steroidal therapy was started with clinical improvement. Relapse led to a second high-dose steroid treatment followed by rituximab with remission. A correlation between serum GAD65-antibodies levels and symptoms was found, demonstrating GAD65-antibodies titers may be useful for clinical follow-up and immunotherapy guidance. This report raises awareness of this serious neurological condition that may be associated with type 1 diabetes, underlining the importance of an early diagnosis and prompt treatment for a better prognosis.

Autoimmune alternating hyper- and hypo-thyroidism: a rare condition in pediatrics

Summary Alternating between hyper- and hypo-thyroidism may be explained by the simultaneous presence of both types of TSH receptor autoantibodies (TRAbs) – thyroid stimulating autoantibodies (TSAbs) and TSH blocking autoantibodies (TBAbs). It is a very rare condition, particulary in the pediatric age. The clinical state of these patients is determined by the balance between TSAbs and TBAbs and can change over time. Many mechanisms may be involved in fluctuating thyroid function: hormonal supplementation, antithyroid drugs and levels of TSAbs and TBAbs. Frequent dose adjustments are needed in order to achieve euthyroidism. A definitive therapy may be necessary to avoid switches in thyroid function and frequent need of therapeutic changes. We describe an immune-mediated case of oscillating thyroid function in a 13-year-old adolescent. After a short period of levothyroxine treatment, the patient switched to a hyperthyroid state that was only controlled by adding an antithyroid drug. Learning points Autoimmune alternating hypo- and hyper-thyroidism is a highly uncommon condition in the pediatric age. It may be due to the simultaneous presence of both TSAbs and TBAbs, whose activity may be estimated in vitro through bioassays. The clinical state of these patients is determined by the balance between TSAbs and TBAbs and can change over time. The management of this condition is challenging, and three therapeutic options could be considered: I-131 ablation, thyroidectomy or pharmacological treatment (single or double therapy). Therapeutic decisions should be taken according to clinical manifestations and thyroid function tests, independent of the bioassays results. A definitive treatment might be considered due to the frequent switches in thyroid function and the need for close monitoring of pharmacological treatment. A definitive treatment might be considered due to the frequent switches in thyroid function and the need for close monitoring of pharmacological treatment.

Premature pubarche: distinguishing between nonclassic congenital adrenal hyperplasia and idiopathic premature adrenarche

Premature Pubarche (PP), or the development of pubic hair before the age of 8 years in girls or 9 years in boys, is most commonly caused by Idiopathic Premature Adrenarche (IPA). There is an increased production of Dehydroepiandrosterone (DHEA) and DHEA Sulfate (DHEAS) by the adrenal zona reticularis without a concomitant rise in Cortisol. IPA is a diagnosis of exclusion and differential diagnosis must include milder and nonclassic variants of Congenital Adrenal Hyperplasia (CAH), that can account for 0 to 40% of cases of PP. Early morning basal 17Hydroxyprogesterone (17OHP) above 200 ng/dL is 100% sensitive and 99% specific for CAH. INTRODUCTION