Disorders of glucose metabolism in Prader-Willi syndrome: Results of a multicenter Italian cohort study.

BACKGROUND AND AIMS: Prader-Willi syndrome (PWS) is characterized by a high incidence of altered glucose metabolism (AGM). However, epidemiological data on impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM) are still discordant. METHODS AND RESULTS: We performed a multicenter study based on 274 PWS patients [144 females, aged 20.3 ± 10.4 yrs (range: 8.1-50.1 years)] evaluating the prevalence for AGM in the entire group, and according to age (children <10 yrs; adolescents 10-18 yrs, and adults >18 yrs), Body Mass Index (BMI = kg/m(2)), gender, genotypes (deletion or uniparental disomy for chromosome 15), and GH therapy (GHT) (untreated, previously or currently treated). Altogether, AGM was detected in 67 (24.4%) of patients (0.7% IFG, 10.2% IGT, 13.5% T2DM). The prevalence of AGM was correlated to age (p = 0.001), BMI (p = 0.001) and HOMA-IR (p = 0.001). However, gender, genotype, and GHT did not influence AGM development in univariate analysis. These data were confirmed as positive predictors when inserted in a multivariate analysis model. CONCLUSION: This study is the first report on the prevalence of AGM in a large population of PWS. Overall, PWS subjects show a high prevalence of AGM that appears more common in obese and adult subjects. Our data confirm the main role of obesity on the individual metabolic risk clustering in PWS, and thus reinforce the concept that improvement in weight control remains the most important goal of any PWS treatment program.

Severe hypoglycemia and ketoacidosis over one year in Italian pediatric population with type 1 diabetes mellitus: a multicenter retrospective observational study.

BACKGROUND AND AIMS: Evaluation of incidence and correlates of severe hypoglycemia (SH) and diabetes ketoacidosis (DKA) in children and adolescents with T1DM. METHODS AND RESULTS: Retrospective study conducted in 29 diabetes centers from November 2011 to April 2012. The incidence of SH and DKA episodes and their correlates were assessed through a questionnaire administered to parents of patients aged 0-18 years. Incidence rates and incident rate ratios (IRRs) were estimated through multivariate Poisson regression analysis and multilevel analysis. Overall, 2025 patients were included (age 12.4 ± 3.8 years; 53% males; diabetes duration 5.6 ± 3.5 years; HbA1c 7.9 ± 1.1%). The incidence of SH and DKA were of 7.7 and 2.4 events/100 py, respectively. The risk of SH was higher in females (IRR = 1.44; 95%CI 1.04-1.99), in patients using rapid acting analogues as compared to regular insulin (IRR = 1.48; 95%CI 0.97-2.26) and lower for patients using long acting analogues as compared to NPH insulin (IRR = 0.40; 95%CI 0.19-0.85). No correlations were found between SH and HbA1c levels. The risk of DKA was higher in patients using rapid acting analogues (IRR = 4.25; 95%CI 1.01-17.86) and increased with insulin units needed (IRR = 7.66; 95%CI 2.83-20.74) and HbA1c levels (IRR = 1.63; 95%CI 1.36-1.95). Mother's age was inversely associated with the risk of both SH (IRR = 0.95; 95%CI 0.92-0.98) and DKA (IRR = 0.94; 95%CI 0.88-0.99). When accounting for center effect, the risk of SH associated with the use of rapid acting insulin analogues was attenuated (IRR = 1.48; 95%CI 0.97-2.26); 33% and 16% of the residual variance in SH and DKA risk was explained by center effect. CONCLUSION: The risk of SH and DKA is mainly associated with treatment modalities and strongly depends on the practice of specialist centers.

Metabolic syndrome in adult patients with Prader-Willi syndrome.

BACKGROUND AND AIMS: Prader-Willi syndrome (PWS), the most common genetic cause of obesity, is characterized by elevated morbility and mortality in all ages. In this context, non-obese PWS children showed low frequency of metabolic syndrome (MetS), while a comparable prevalence was observed in obese PWS and obese controls. Aim of this study was to estimate the occurrence of MetS and its components in a large group of PWS adults, according to obesity status. METHODS AND RESULTS: A cross-sectional study was performed in 108 PWS aged 18.0-43.2 years (87 obese and 21 non-obese) and in 85 controls with nonsyndromic obesity matched for age, gender, and BMI with obese PWS. Non-obese PWS showed lower waist circumference, insulin, HOMA-index, triglycerides, diastolic blood pressure, and higher HDL-C than both obese PWS and obese controls (p < 0.017). Obese PWS showed higher glucose and systolic blood pressure than both non-obese PWS and obese controls (p < 0.017). MetS was found in 1/21 (4.8%) non-obese PWS, 36/87 (41.4%) obese PWS and 39/85 (45.9%) obese controls. Non-obese PWS showed lower frequency for each MetS component as compared with obese PWS and obese controls. PWS patients with deletion of the chromosome 15q11-13 showed a lower risk for low HDL-C (p < 0.01) and a trend towards a lower MetS risk (p < 0.06) compared to subjects without deletion. CONCLUSION: Our findings suggest the main role that obesity status plays on the individual metabolic risk clustering in PWS adults. Early identification of MetS could be helpful to improve morbidity and prevent mortality in such patients.

Early onset of puberty in young girls: an Italian cross-sectional study.

BACKGROUND: International literature and clinical practice have referred to Marshall and Tanner data to define the physiological age at onset of puberty. A study in the United States (1997) showed an anticipation in pubertal onset, whereas several European studies did not confirm this trend. AIM: To describe the onset of secondary sexual characteristics in a large Italian population of girls and to compare it to reference literature data. SUBJECTS AND METHODS: A cross-sectional study on 7311 2-14-yr-old girls who spontaneously requested a clinical evaluation for routine health check-up or acute illness by family pediatrician's offices in a northern Italian region (Lombardy), between September 2005 and November 2006. Trained family pediatricians performed a complete physical examination; pubertal status was evaluated following Tanner's criteria; breast development was assessed by palpation. RESULTS: Mean age of thelarche (B2), pubarche (PH2), menarche were 9.75, 10.09, and 12.49 yr, respectively. The prevalence of B2 and PH2 at ages 7-7.99 was 5.9% and 5.6%, respectively, at ages 8-8.99 was 15.5% and 13.8%, respectively. Mean time lapse from B2 to B3 and B2 to menarche was 1.46 and 2.74 yr, respectively. Mean age at menarche of our population and their respective mothers was almost identical. CONCLUSIONS: Our population presented earlier clinical signs of pubertal development than those defined by Marshall and Tanner. Mean age of menarche was not different in comparison to the previous generation. A different progression of pubertal development was found, in which the shift to B3 may have more clinical relevance.

Metabolic syndrome in children with Prader-Willi syndrome: the effect of obesity.

BACKGROUND AND AIMS: Prader-Willi syndrome (PWS), the most frequent syndromic obesity, is associated with elevated morbidity and mortality in pediatric and adult ages. In PWS, the presence of metabolic syndrome (MS) has not yet been established. The aim of the study was to estimate the frequency of MS and its components in pediatric subjects according to obesity status. METHODS AND RESULTS: A cross-sectional study was performed in 109 PWS children aged 2-18 years (50 obese and 59 non-obese) and in 96 simple obese controls matched for age, gender, and also for BMI with obese PWS. Obesity was defined when SDS-BMI was >2. Non-obese PWS showed significantly lower frequency of hypertension (12%) than obese PWS (32%) and obese controls (35%)(p=0.003). The same was observed for low HDL-cholesterol (3% vs 18% and 24%, p=0.001) and high triglycerides (7% vs 23% and 16%, p=0.026). Frequency of altered glucose metabolism was not different among groups (2% vs 10% and 5%), but type 2 diabetes (four cases) was present only in obese PWS. Non-obese PWS showed lower insulin and HOMA-index respect to obese PWS and obese controls (p ≤ 0.017). Overall MS frequency in PWS was 7.3%. None of the non-obese PWS showed MS compared with 16% of obese PWS and controls (p<0.001). When obesity was excluded from the analysis, a significantly lower frequency for clustering of ≥ 2 factors was still found in non-obese PWS (p=0.035). CONCLUSION: Non-obese PWS showed low frequency of MS and its components, while that observed in obese PWS was very close to those of obese controls, suggesting the crucial role of obesity status. Prevention of obesity onset remains the most important goal of PWS treatment. Early identification of MS could be helpful to improve morbidity and mortality in such patients.

A survey on Prader-Willi syndrome in the Italian population: prevalence of historical and clinical signs.

Clinical criteria for the diagnosis of Prader-Willi Syndrome (PWS) were established by consensus in 1993 (Holm et al.). Specific molecular testing is now available and the purpose of diagnostic criteria has shifted to identify individuals to test, thus avoiding the expense of unnecessary analysis. The aim of this study was to find clinical indicators to select patients with suspected PWS for laboratory testing. We analyzed the prevalence of clinical signs and symptoms in 147 genetically diagnosed Italian patients with PWS (67 males and 80 females), aged from 9 months to 34.6 years (13.6 +/- 8.3 years), using the consensus diagnostic criteria, and according to age, sex and type of genetic abnormality. The prevalence of several clinical features changed significantly with age, but very few with sex. According to genetic subtypes (deletion vs UPD), only hypopigmentation and acromicria were more frequent in patients with deletion. Some criteria considered as minor or supportive by Holm et al. have higher prevalence than some major criteria. In conclusion, in order to identify patients with suspected PWS to submit to laboratory testing, we recommend a classification of clinical criteria according to age, giving more attention to those so-called minor or supportive criteria.

17beta-Hydroxysteroid dehydrogenase-3 deficiency: from pregnancy to adolescence.

OBJECTIVE: Aim of this study is to report on basal clinical phenotype and follow up after diagnosis, of patients with 17beta-hydroxysteroid-dehydrogenase type 3 (17beta-HSD3) deficiency in Italy. SETTING: Pediatric Endocrine Departments, University Hospitals. PATIENTS: The cases of 5 Italian subjects affected by 17beta-HSD3 deficiency are presented in this study. INTERVENTIONS: Laboratory and genetic assessment. Gonadectomy and female sex assignment (4 patients) or GnRH analog therapy to regress puberty and gender identity disorder (1 patient). RESULTS: Presentation lasted from pregnancy (pre-natal diagnosis of a 46,XY fetus with female external genitalia) to infancy (inguinal hernia containing testes/clitoromegaly) and adolescence (virilisation). All subjects but one (subject 1, Central-Northern Italy) were from small areas of Southern Italy. Endocrine data (baseline and/or stimulated testosterone/ Delta4-androstenedione ratio) were informative. Two girls were homozygous for 17beta-HSD3 gene mutations (G289S/G289S; R80W/R80W), while the others were compound heterozygous (IVS325+4 A>T/A203V; L212Q/M235V; R80W/A235E). Four patients were confirmed as females and were well-adjusted with assigned sex; gender identity disorder improved during treatment with GnRH analog in the last subject. CONCLUSIONS: 17betaHSD3 deficiency may present from pregnancy to puberty for different clinical issues. Albeit testosterone/Delta4-androstenedione ratio represents the most accurate endocrine marker to diagnose the disorder, hCGstimulation is mandatory in pre-puberty. Molecular analysis of 17beta-HSD3 gene should be performed to confirm the diagnosis. Temporary GnRH analog treatment may regress gender identity disorder and provide time to confirm or change the birth sex assignment. Female individuals seems to be compliant with their sex, providing that virilisation does not occur. In Italy, the disorder seems to be more prevalent in the Southern regions and shows genetic heterogeneity.

Short-term effects of growth hormone treatment on the upper airways of non severely obese children with Prader-Willi syndrome.

AIMS: The aim of this study was to establish whether short-term GH treatment causes obstructive apnea in patients with Prader-Willi syndrome and normal upper airway patency. SUBJECTS AND METHODS: We performed an observational longitudinal 6-week GH treatment study. Thirty-four non-severely obese Prader-Willi syndrome patients (20 boys, age range 0.94-11.8 yr, median 2.24 yr) entered an observational longitudinal 6-week study. Sixteen boys received recombinant human GH (rhGH) treatment; the remaining 18 represented the control group and received no treatment. Polysomnography monitoring and othorhinolaringoiatric video endoscopy were performed one night before and after 6 weeks of rhGH treatment (0.03 mg/kg body weight/day). All patients underwent auxologic assessment, fasting blood glucose, insulin and IGF-I evaluation. The main polysomnographic parameter considered was total apnea hypopnea index, consisting of two components: central apnea hypopnea index and obstructive apnea hypopnea index. All patients were free of severe or moderate upper airway obstruction when rhGH treatment began. RESULTS: After 6 weeks of rhGH therapy, obstructive apnea hypopnea index increased in 8/16 (50%), decreased in 5/16 (31%), and did not change in 3/16 (19%) patients. The changes were not statistically significant. The rhGH-treated group did not differ from the control group for the apnea hypopnea index both before and after 6 weeks of treatment. Adenoids and tonsils showed a slight increase in 1 and 2 patients on rhGH treatment, respectively, and did not change in the untreated patients. CONCLUSIONS: Our data show that short-term rhGH treatment does not cause restrictions of the upper airways in patients with Prader-Willi syndrome and normal upper airway patency.

Congenital hypothyroidism with gland in situ: diagnostic re-evaluation.

In the past, most congenital hypothyroidism (CH) children with thyroid gland in situ were considered to be affected by hormonogenesis defect. Nowadays, the improved sensitivity of neonatal screening, novel insights into the pathogenic mechanisms and the advances of genetic analyses have reopened the discussion about the etiology of CH with thyroid in situ. We report the etiological re-evaluation of 31 children with thyroid in situ, who had been identified by the CH screening program. The purposes of this re-evaluation were: a) to investigate the definitive diagnosis and pathogenetic mechanism of CH with thyroid in situ in eligible children suspected of dyshormonogenetic defect and b) to verify the adequacy of the treatment schedules. Thirty out of 31 children were affected with permanent hypothyroidism and only one child was euthyroid at re-evaluation (transient CH). Thyroid hormone organification defects were present in less than half of the CH patients with thyroid in situ (13/30); a higher prevalence of partial defects of iodine organification than severe or complete forms was found. An inactivating TSH-receptor gene mutation was found in only one patient without iodine organification defect. Some questions remain unanswered concerning the adequacy of the schedules of treatment, particularly about the proper treatment of mild and borderline forms of CH.

Identification of a novel polymorphism in the fibronectin type II domain of the SEL1L gene and possible relation to the persistent hyperinsulinemic hypoglycemia of infancy.

SEL1L, a human gene located on chromosome 14q24.3-q31, is highly expressed in adult pancreas. It is proximal to D14S67 (IDDM11) a proposed type I diabetes susceptibility locus. Considering the organ specific expression of SEL1L, a fundamental role of SEL1L in pancreatic growth can be hypothesized. While screening for mutations in young diabetic patients, in children affected by persistent hyperinsulinemic hypoglycemia of infancy (PHHI), in patients with non-functional endocrine tumours and in over 100 control subjects, we identified a novel polymorphism (D162G) residing on the fourth exon of the gene. This exon encodes for the fibronectin type II domain and the nucleotide change involves a highly conserved amino acid. The D162G polymorphism induces a major change in the amino acid composition producing a possible disruptive role in collagen binding.

Thyroid function and puberty.

Thyroid hormones are essential for normal growth, sexual development and reproductive function. During puberty, changes in thyroid functions and an increase in thyroid volume occur as an adaptation to body and sexual development. Hypothyroidism diagnosed late in prepubertal years, usually due to Hashimoto's thyroiditis, can cause a delay of puberty or incomplete isosexual precocity (development of breast and internal genitalia in girls and increased testis volume in boys without adrenarche). In contrast, normal pubertal development and adequate menarche have been documented in congenital hypothyroidism detected by neonatal screening and treated early. The effect of hyperthyroidism on pubertal development is not well known, but a short period of hyperthyroidism seems not to have major negative effects. In adolescence or young adulthood, menstrual dysfunction, infertility, and stillbirth or premature birth are associated with thyroid dysfunction.

Final height in congenital adrenal hyperplasia due to 21-hydroxylase deficiency: the Italian experience.

OBJECTIVE: To investigate the influence of target height (TH), gender, phenotype, glucocorticoid formulation and age at onset of treatment on final height (FH) in patients with 21-hydroxylase deficiency (21OHD). PATIENTS: Clinical data of 93 patients--46 simple virilizing (SV), 35 salt-wasting (SW) and 12 late onset (LO)--were collected in six pediatric endocrinology units in Italy. RESULTS: FH and TH were always below the mean height of the general population (mean FH, SDS: SW patients -1.3 +/- 1.2, SV patients -1.8 +/- 0.9, LO patients -1.7 +/- 1.1; mean TH, SDS: SW patients -0.6 +/- 0.8, SV patients -0.7 +/- 0.9, LO patients -1.4 +/- 1.3). FH was significantly below TH in patients with classic form (SW and SV, p <0.001), but not in LO patients. In classic form, TH seems to be related to FH, followed by age at onset of therapy and by steroid formulation, these variables explaining 30% of FH variance. CONCLUSIONS: In the classic form, substitutive therapy started before 21 months of age improved the long-term outcome. Lower TH in LO patients could be due to undiagnosed non-classic 21OHD in some of their parents. FH in LO patients seems not to benefit from corticosteroid therapy, even if late diagnosis may partly account for this result.

Highly active antiretroviral-treated HIV-infected children show fat distribution changes even in absence of lipodystrophy.

BACKGROUND: Combined use of dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) allows a precise estimate of regional body composition and intra-abdominal adipose tissue (IAT). Data on body composition in HIV-infected children (HIV+) receiving highly active antiretroviral therapy (HAART) with (LD+) and without (LD-) lipodystrophy are lacking. METHODS: DXA scans were performed in 34 HIV+: six LD+, 28 LD- and 34 pair-matched (age, sex and body mass index) healthy controls (HC): six for LD+ (HC+) and 28 for LD- (HC-). MRI scans were performed in 16 HIV+: six LD+, 10 LD- and 16 pair-matched (age and sex) HC. Data were analysed by analysis of variance, post hoc Fisher test and Mann-Whitney test. RESULTS: LD+ and LD- were similar for: previous exposure to zidovudine/zidovudine + didanosine, months on HAART (stavudine + lamuvidine + one protease inhibitor), CD4+ cells, patients with HIV-RNA < 50 copies/ml. In HIV+ and HC, fat mass and distribution were significantly different, whereas lean mass was comparable. Thus, LD+ and LD- as compared to HC+ and HC- respectively showed: (1) reduced fat amount and percentage; (2) lower truncal fat mass; (3) markedly reduced limbs fat mass. Within the HIV+ group, (4) LD+ showed higher fat trunk/fat total (P = 0.04) and lower fat limbs/ fat total ratios (P = 0.009) than LD-; (5) LD+ showed larger IAT areas than LD- and HC (P < 0.0003). CONCLUSIONS: Increased central fat and peripheral lipoatrophy are distinctive features of all HAART-treated children. Changes in body fat composition are detectable by DXA even in the absence of signs of Lipodystrophy. Only LD+ show true central obesity.