Association between non-alcoholic fatty liver disease and subclinical hypothyroidism in children with obesity.

PURPOSE: We aimed (i) evaluating the relationship between non-alcoholic fatty liver disease (NAFLD) and thyroid function tests, (ii) testing if the relationship between NAFLD and thyroid dysfunction could be driven by the obesity and the IR degree, and (iii) exploring the influence of the patatin-like phospholipase domain-containing protein-3 (PNPLA3) I148M and the transmembrane 6 superfamily member 2 (TM6SF2) E167K polymorphisms on the association between NAFLD and thyroid function in children. METHODS: We examined 2275 children and adolescents with obesity. Subclinical hypothyroidism (SH) was defined by thyroid-stimulating hormone (TSH) > 4.2 µUI/ml with normal fT3 and fT4. RESULTS: Children with NAFLD showed higher SH prevalence than those without NAFLD (15.7% Vs 7.4%;p = 0.001) and showed an adjusted odds ratio (aOR) to have SH of 1.68 (95% CI:1.01-2.80;p = 0.04) while patients with SH had an aOR to show NAFLD of 2.13(95% CI:1.22-3.73;p = 0.008). Patients having severe obesity and IR degree presented an aOR to show both NAFLD and SH of 3.61 (95% CI:1.78-7.33;p < 0.0001). Subjects with NAFLD carrying the TM6SF2 167 K allele had lower TSH levels than non-carriers (p = 0.03) and showed an aOR to have SH of 0.10 (95% CI: 0.01-0.79;p = 0.02). No differences were found in carriers of the PNPLA3 148 M allele. A general linear model for TSH variance showed a significant association of TSH with TM6SF2 genotypes only in the NAFLD group (p = 0.001). CONCLUSION: Children with obesity and NAFLD presented increase risk of SH and vice versa likely due to the adverse effect of duration of obesity, obesity degree, and IR. The TM6SF2 E167K exerts a protective role against SH in children with obesity and NAFLD.

Expanding the phenotype of RTTN variations: a new family with primary microcephaly, severe growth failure, brain malformations and dermatitis.

Primary autosomal recessive microcephaly (MCPH) is a developmental disorder characterized by prenatal onset of abnormal brain growth. MCPH occurs both alone and as part of a broad range of neurodevelopmental syndromes with or without cortical malformations and growth retardation. Here we report a consanguineous Moroccan family with two siblings affected by severe primary microcephaly, failure to thrive, congenital dermatitis and severe developmental delay. Brain magnetic resonance imaging showed lissencephaly of frontal lobes and periventricular heterotopia of the gray matter. We performed both Comparative Genomic Hybridization array and whole exome sequencing (WES) analyses of the kindred. No quantitative defects were detected. However, WES identified a new homozygous missense variation in the penultimate nucleotide of exon 23 of RTTN gene (c.2953A>G;pArg985Gly). cDNA sequencing revealed two abnormal spliced products, one lacking only exon 23 and the other lacking exons 22 and 23 (out-of-frame). RTTN is a protein involved in cilia structure and function. Homozygous mutations in RTTN gene have been described in bilateral diffuse isolated polymicrogyria and, more recently, in microcephalic primordial dwarfism (PD). We found a novel homozygous mutation in RTTN associated with microcephalic PD as well as complex brain malformations and congenital dermatitis, thus expanding the phenotypic spectrum of both RTTN-associated diseases and ciliary dysfunction.

'Frequently recurring' nocturnal polyuria is predictive of response to desmopressin in monosymptomatic nocturnal enuresis in childhood.

INTRODUCTION: The nocturnal polyuria is considered a significant predictive value for response to desmopressin. The cutoff value useful to define nocturnal polyuria is still a matter of debate. Moreover, it is current notion that maximal voided volume (MVV) could be used as a predictor for desmopressin response. OBJECTIVE: The objective of this study was to assess the impact of different definitions of nocturnal polyuria (and of its frequency) and MVV in predicting the response to desmopressin. STUDY DESIGN: A total of 103 patients with frequent monosymptomatic nocturnal enuresis (≥4 wet nights/week) were enrolled. A bladder diary over a 4-day period was collected. The MVV was defined as the highest micturition volume detected at bladder diary. Nocturnal diuresis was measured in 5 wet nights. Then, patients were administered with 120 mcg of sublingual desmopressin. After 2 months, if there was no complete response, the dose was increased to 240 mcg. Nocturnal polyuria was defined as follows: 1.Definition 1: nocturnal urine production >130% of the expected bladder capacity (EBC). 2. Definition 2: >100% EBC. 3. Definition 3: > 20×(age + 9) mL. The primary outcome was 'response to desmopressin' after 3 months of treatment. RESULTS: Fifty-three patients responded to desmopressin. Comparing the responses to desmopressin on the basis of the three definitions of nocturnal polyuria, no significant difference was found. There was no cutoff value of nocturnal polyuria expressed as %EBC useful in providing a significant receiver-operating characteristic (ROC) curve. The area under the ROC curve for MVV expressed as %EBC was 0.67 (95% confidence interval [CI], 0.54-0.80; p = 0.01). A MVV >103.1% of EBC had 78.8% (95% CI, 61.1-91.0) sensitivity and 47.5% (95% CI, 31.5-63.9) specificity for predicting response to desmopressin. Among the patients with nocturnal polyuria according to definition 1, a higher percentage of subjects with nocturnal polyuria in 4 out of 5 or 5 out of 5 nights responded to desmopressin, compared with other patients. Patients presenting with nocturnal polyuria according to definition 3 in 5 out of 5 nights showed a 100% of response to desmopressin. At multivariate analysis, the only significant odds ratio (OR) to respond to desmopressin was that of patients with nocturnal polyuria according to definition 1 in >3 nights (OR = 7.1, 95% CI, 1.3-40.3). DISCUSSION AND CONCLUSIONS: The presence or absence of nocturnal polyuria-according to all three definitions-in at least one night was not effective in predicting the response to desmopressin. Predictors of desmopressin response were nocturnal polyuria in >3 out of 5 wet nights according to definition 1 and in 5 out of 5 wet nights according to definition 3.

TM6SF2 Glu167Lys polymorphism is associated with low levels of LDL-cholesterol and increased liver injury in obese children.

BACKGROUND: The Glu167Lys (E167K) transmembrane 6 superfamily member 2 (TM6SF2) variant has been associated with liver steatosis, high alanine transaminase (ALT) levels and reduced plasma levels of liver-derived triglyceride-rich lipoproteins. OBJECTIVES: The objectives of this study were to investigate in a group of obese children the association among the 167K allele of TM6SF2 gene and ALT, cholesterol and triglycerides levels, and hepatic steatosis, and to evaluate the potential interaction between this variant and the I148M patatin like phospholipase 3 gene (PNPLA3) polymorphism on liver enzymes. METHODS: We genotyped 1010 obese children for TM6SF2 E167K and PNPLA3 I148M polymorphisms. Anthropometrical and biochemical data were collected. Ultrasound imaging of the liver was performed. RESULTS: The 167K allele showed an association with steatosis (P < 0.0001), higher ALT levels (P < 0.001) and lower total cholesterol (P < 0.00001), low-density lipoprotein cholesterol (P < 0.0001), triglycerides (P = 0.02) and non-high-density lipoprotein cholesterol levels (P < 0.000001). The subjects homozygous for the PNPLA3 148M allele carrying the rare variant of TM6SF2 showed an odds ratio of 12.2 (confidence interval 3.8-39.6, P = 0.000001) to present hypertransaminasaemia compared with the remaining patients. CONCLUSION: Although the TMS6SF2 E167K variant predisposes the obese children to non-alcoholic fatty liver disease, there is an association between this variant and lower levels of cardiovascular risk factors. Overall, the data suggest differential effects of TMS6SF2 E167K variant on liver and heart health.

[Health consequences of obesity in children and adolescents]. / Conseguenze dell'obesità sulla salute del bambino e dell' adolescente.

Obesity in childhood is associated with the presence of complications that can undermine health immediately or in the long term. Several conditions, such as pulmonary or orthopedic complications are strictly associated with the severity of overweight, since they are directly associated to the mechanic stress of fat tissue on the airways or on the bones. Other conditions, such as metabolic or liver complications, although increasing with the extent of overweight, are associated with insulin resistance, which can be modulated by different other factors (ethnicity, genetics, fat distribution) and can occur in overweight children as well. No less important are psychological correlates, such as depression and stigma, which can seriously affect the health related quality of life. Pediatric services for the care of childhood obesity need to be able to screen overweight and obese children for the presence of physical and psychological complications, which can be still reversed by weight loss. This article provides pediatricians a comprehensive update on the main complications in obese children and adolescents and their treatment.