Is Neck Circumference an Indicator for Metabolic Complication of Childhood Obesity?

BACKGROUND: The possible role of neck circumference (NC) for screening childhood obesity and its complication is not well characterized. AIM: To assess NC and to explore its increase as risk factor with metabolic syndrome (MS) variables. METHODS: Cross sectional case-control study included 50 obese children (BMI ≥95(th) percentile) and 50 healthy (BMI 15(th)-<85(th) percentile). All were subjected to clinical examination, measuring blood pressure (BP), body weight, height, NC, waist (WC) and hip (HC)., fasting blood glucose, insulin and lipid profile. RESULTS: MS was detected among 52% of obese participants, but not among controls (0%). Clinical parameters and most of the laboratory values were higher in subjects with MS than in non-metabolic subjects, with statistical significance only in blood pressure and triglycerides. Among obese without MS, NC showed significantly positive correlations with age, weight, height, WC, HC and negative with LDL. While among Obese with MS, NC showed significantly positive correlations with age, weight, height, BMI-SDS, WC, HC and DBP. CONCLUSION: NC can be considered as a good indicator and predictor for obesity, especially central obesity. However, NC has no relation with lipid profile or fasting blood sugar.

Neck Circumference as a Predictor of Adiposity among Healthy and Obese Children.

BACKGROUND: Obesity, particularly in the upper part of body, is a major health problem. Because body mass index (BMI) does not adequately describe regional adiposity, other indices of body fatness are being explored. OBJECTIVES: To determine if neck circumference is a valid measure of adiposity (fat distribution) among group of Egyptian children. SUBJECTS AND METHODS: This is a cross sectional study, included 50 obese subjects, aged 7 - 12 years recruited from Endocrine, obesity and Metabolism Pediatric Unit at Children Hospital, Cairo University and 50 healthy children, age and sex matched. All children were subjected to blood pressure assessment (systolic SBP and diastolic DBP), and anthropometric assessment (body weight, height, neck circumference (NC), waist (WC) and hip (HC) circumferences, and skin fold thicknesses at three sites: biceps, triceps and sub scapular. BMI [weight (kg)/height (m2)] was calculated. RESULTS: In healthy females, significant associations were detected between NC and SBP, DBP and all anthropometric measurements. However, in healthy males NC was not significantly associated with BMI, SBP and DBP. In the obese group; both sexes; insignificant association was found between NC and SBP, DBP, BMI and skinfold thickness. CONCLUSION: NC is related to fat distribution among normal healthy female children. However, this relation disappears with increasing adiposity. The results do not support the use of NC as a useful screening tool for childhood obesity.

The role of anti-Mullerian and inhibin B hormones in the evaluation of 46,XY disorders of sex development.

OBJECTIVE: To assess the sensitivity and specificity of anti-Mullerian hormone (AMH) and inhibin B for diagnosis of 46,XY disorders of sex development (DSD). PATIENTS AND METHODS: The study included 43 patients of 46,XY DSD and compared them with 43 healthy, male, age matched controls. All patients underwent karyotyping, assessment of testosterone, dihydrotestosterone (DHT) and Δ4-androstendione (Δ4A) basal and after human chorionic gonadotropin (HCG) testing. Basal dehydroepiandrosterone (DHEA) was measured. Ultrasonograghy was also done and some cases underwent laparoscopy or gonadal biopsies. Basal AMH and inhibin B were measured in both cases and controls. RESULTS: The mean age of patients was 5.16±4.24 years. There were significant correlations between basal AMH and HCG stimulated testosterone and DHT (r=0.64; p<0.001 and r=0.52; p<0.001, respectively). Also, significant positive correlations were found between inhibin B and HCG as well as stimulated testosterone and DHT (r=0.62; p<0.001 and r=0.44; p=0.003, respectively). A highly significant correlation was found between AMH and inhibin B (r=0.78; p<0.001). The sensitivity of AMH was (96.6%), specificity (60.7%), NPV (89.5%) and PPV (83.6%). Best cut-off value was (27.11 IU/mL) while overall accuracy was (85%). The sensitivity of inhibin B was (96.6%), specificity (67.9%), NPV (90.5%), PPV (86.2%), and best cut-off value was (41.9 IU/mL) with an overall accuracy (87%). CONCLUSION: AMH and inhibin B are valuable, and reliable noninvasive parameters for the detection of functioning testicular tissues in prepubertal patients.

Analysis of the gene coding for steroidogenic factor 1 (SF1, NR5A1) in a cohort of 50 Egyptian patients with 46,XY disorders of sex development.

OBJECTIVE: Steroidogenic factor 1 (SF1, NR5A1) is a key transcriptional regulator of genes involved in the hypothalamic-pituitary-gonadal axis. Recently, SF1 mutations were found to be a frequent cause of 46,XY disorders of sex development (DSD) in humans. We investigate the frequency of NR5A1 mutations in an Egyptian cohort of XY DSD. DESIGN: Clinical assessment, endocrine evaluation and genetic analysis of 50 Egyptian XY DSD patients (without adrenal insufficiency) with a wide phenotypic spectrum. METHODS: Molecular analysis of NR5A1 gene by direct sequencing followed by in vitro functional analysis of the two novel missense mutations detected. RESULTS: Three novel heterozygous mutations of the coding region in patients with hypospadias were detected. p.Glu121AlafsX25 results in severely truncated protein, p.Arg62Cys lies in DNA-binding zinc finger, whereas p.Ala154Thr lies in the hinge region of SF1 protein. Transactivation assays using reporter constructs carrying promoters of anti-Müllerian hormone (AMH), CYP11A1 and TESCO core enhancer of Sox9 showed that p.Ala154Thr and p.Arg62Cys mutations result in aberrant biological activity of NR5A1. A total of 17 patients (34%) harboured the p.Gly146Ala polymorphism. CONCLUSION: We identified two novel NR5A1 mutations showing impaired function in 23 Egyptian XY DSD patients with hypospadias (8.5%). This is the first study searching for NR5A1 mutations in oriental patients from the Middle East and Arab region with XY DSD and no adrenal insufficiency, revealing a frequency similar to that in European patients (6.5-15%). We recommend screening of NR5A1 in patients with hypospadias and gonadal dysgenesis. Yearly follow-ups of gonadal function and early cryoconservation of sperms should be performed in XY DSD patients with NR5A1 mutations given the risk of future fertility problems due to early gonadal failure.