Hunger and Satiety Peptides: Is There a Pattern to Classify Patients with Prader-Willi Syndrome?

Hyperphagia is one of the main problems of patients with Prader-Willi syndrome (PWS) to cope with everyday life. The underlying mechanisms are not yet well understood. Gut-brain hormones are an interrelated network that may be at least partially involved. We aimed to study the hormonal profile of PWS patients in comparison with obese and healthy controls. Thirty adult PWS patients (15 men; age 27.5 ± 8.02 years; BMI 32.4 ± 8.14 kg/m2 ), 30 obese and 30 healthy controls were studied before and after eating a hypercaloric liquid diet. Plasma brain-derived neurotrophic factor (BDNF), leptin, total and active ghrelin, peptide YY (PYY), pancreatic polypeptide (PP), Glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and amylin were determined at times 00 , 300 , 600 and 1200 . Cluster analysis was used. When considering all peptides together, two clusters were established according to fasting hormonal standardized concentrations. Cluster 1 encompassed most of obese (25/30) and healthy controls (28/30). By contrast, the majority of patients with PWS were located in Cluster 2 (23/27) and presented a similar fasting profile with hyperghrelinemia, high levels of leptin, PYY, GIP and GLP-1, compared to Cluster 1; that may reflect a dysfunction of these hunger/satiety hormones. When peptide behavior over the time was considered, PP concentrations were not sustained postprandially from 60 min onwards in Cluster 2. BDNF and amylin did not help to differentiate the two clusters. Thus, cluster analysis could be a good tool to distinguish and characterize the differences in hormone responses between PWS and obese or healthy controls

Revisiting the usefulness of the short acute octreotide test to predict treatment outcomes in acromegaly

Introduction: We previously described that a short version of the acute octreotide test (sAOT) can predict the response to first-generation somatostatin receptor ligands (SRLs) in patients with acromegaly. We have prospectively reassessed the sAOT in patients from the ACROFAST study using current ultra-sensitive GH assays. We also studied the correlation of sAOT with tumor expression of E-cadherin and somatostatin receptor 2 (SSTR2) .Methods: A total of 47 patients treated with SRLs for 6 months were evaluated with the sAOT at diagnosis and correlated with SRLs' response. Those patients whose IGF1 decreased to = 3SDS, were considered non-responders. The 2 hours GH value (GH2h) after s.c. administration of 100 mcg of octreotide was used to define predictive cutoffs. E-cadherin and SSTR2 immunostaining in somatotropinoma tissue were investigated in 24/47 and 18/47 patients, respectively.Results: In all, 30 patients were responders and 17 were non-responders. GH(2h) was 0.68 (0.25-1.98) ng/mL in responders vs 2.35 (1.59-9.37) ng/mL in non-responders (p<0.001). GH(2h) = 1.4ng/mL showed the highest ability to identify responders (accuracy of 81%, sensitivity of 73.3%, and specificity of 94.1%). GH(2h) = 4.3ng/mL was the best cutoff for non-response prediction (accuracy of 74%, sensitivity of 35.3%, and specificity of 96.7%). Patients with E-cadherin-positive tumors showed a lower GH(2h) than those with E-cadherin-negative tumors [0.9 (0.3-2.1) vs 3.3 (1.5-12.1) ng/mL; p<0.01], and patients with positive E-cadherin presented a higher score of SSTR2 (7.5 +/- 4.2 vs 3.3 +/- 2.1; p=0.01).Conclusion: The sAOT is a good predictor tool for assessing response to SRLs and correlates with tumor E-cadherin and SSTR2 expression. Thus, it can be useful in clinical practice for therapeutic decision-making in patients with acromegaly

Síndrome de Prader-Willi como modelo de obesidad: Ghrelina, péptido YY, adiponectina y parámetros inflamatorios

[spa] El síndrome de Prader-Willi (SPW) es la causa de obesidad genética más frecuente. Está provocado por una falta de expresión de los genes de la región cromosómica 15q11-13. Adémas de desarrollar una obesidad mórbida, asocian retraso mental, una facies característica, hipogonadismo hipogonadotropo y déficit de hormona de crecimiento. El control de la ingesta y del peso corporal es un proceso complejo en el que intervienen señales periféricas que informan sobre la adiposidad del organismo y otras que se producen en el tracto gastrointestinal que producen saciedad como el péptido YY (PYY). Por otra parte, la ghrelina, secretada en su mayoría por el estómago, estimula la ingesta. Finalmente, la adiponectina, fabricada en el tejido adiposo, y algunas proteínas relacionadas con la inflamación intervienen también en la regulación del metabolismo. En esta tesis se estudian ghrelina, PYY, adiponectina y proteínas relacionadas con la inflamación (IL-6, IL-18, PCR, C3 y TNF-alfa) tanto en ayunas como tras la ingesta de una dieta líquida estándar en pacientes adultos con SPW y se compara con sujetos obesos de igual índice de masa corporal y sujetos con normopeso. La ghrelina en ayunas fue superior en los pacientes con SPW. Tras la ingesta, la concentración de ghrelina disminuyó en los tres grupos pero en los pacientes con SPW, el descenso fue menos marcado, de forma que el área bajo la curva (AUC) de ghrelina fue superior en estos pacientes comparado con los sujetos obesos. La concentración de PYY en ayunas fue inferior en los pacientes con SPW que en los otros dos grupos y, tras la ingesta, ascendió de forma menos marcada, a diferencia de lo observado en los sujetos obesos y con normopeso, en los que se produjo un pico de PYY a los 60 minutos. La concentración de PYY fue inversamente proporcional a la ghrelina en ayunas y al AUC de ghrelina, pudiendo además considerarse un predictor de esta última. El incremento de PYY tras la ingesta se correlacionó negativamente con el descenso de ghrelina en los pacientes con SPW en los minutos 60 y 120. La concentración de adiponectina en ayunas fue inferior en los pacientes con SPW respecto a los sujetos con normopeso, pero superior a la de los sujetos obesos. No se observó ningún cambio en las concentraciones de adiponectina tras la ingesta ni en el grupo de sujetos obesos ni en el grupo con normopeso. Se observó un descenso del 13% en la adiponectina en el minuto 240 en el grupo con SPW. El AUC de adiponectina fue similar en los tres grupos. Los sujetos obesos, con o sin SPW, mostraron concentraciones superiores en ayunas de algunos marcadores de inflamación comparado con el grupo de sujetos con normopeso. Además, comparado con los sujetos obesos, los pacientes con SPW mostraron concentraciones superiores de C3, IL-18, IL-6 y PCR, indicando que presentan aún un mayor grado de inflamación. No se observaron cambios tras la ingesta de ninguna de la proteínas de inflamación, de forma que persistieron elevadas aquellas que ya lo estaban en ayunas. La concentración de IL-18 se correlacionó negativamente con la testosterona en los varones con SPW. En conclusión, la hiperghrelinemia observada en los pacientes con SPW podría estar relacionada con una disminución de la concentración de PYY. La obesidad que acompaña al SPW, cursa con concentraciones de adiponectina y proteínas relacionadas con la inflamación superiores a los observados en la obesidad esencial.[eng] Prader-Willi syndrome (PWS) is considered as one of the most common causes of genetic obesity in humans. The characteristic clinical features include neonatal hypotony, mental retardation, behavioural abnormalities and excessive appetite with progressive massive obesity. The aim of the study was to investigate fasting and postprandial ghrelin, peptide YY, adiponectin and inflammation-related proteins levels in PWS patients as compared to obese and lean subjects and whether they could contribute to the pathogenesis of obesity in this syndrome. We studied 7 patients with PWS, 16 obese patients and 42 lean subjects for the fasting study. From this group, we evaluated 7 patients with PWS, 7 age-sex-BMI-matched obese non-PWS and 7 age-sex-matched lean subjects before and after the administration of 750 Kcal of a standard liquid meal. Fasting ghrelin levels were higher in PWS than in the other two groups. Fasting PYY levels were lower in patients with PWS than in lean subjects but similar to those in obese subjects. The postpradial decrease in ghrelin concentrations was lower in PWS as compared to the other two groups. PYY response after the meal was blunted in patients with PWS, but not in the other two groups. Fasting PYY levels correlated negatively with fasting ghrelin levels and with ghrelin AUC and they were the only predictor for ghrelin AUC. The increase in PYY correlated negatively with the decrease in ghrelin in times 60 min and 120 min in PWS. Fasting plasma adiponectin levels were lower in PWS than in lean subjects but higher than in obese patients. After the meal, adiponectin concentrations mildly decreased in PWS at time point 240 min, while in obese and lean subjects no changes were observed. However, the adiponectin AUC was similar in all three groups. Compared to non-PWS, PWS subjects showed higher plasma concentrations of CRP, C3, IL-18 and IL-6 that persisted postprandially elevated for CRP, C3 and IL-18. TNF-alpha did not differ between the three groups. These results were independent from IGF-1 levels, HOMA index, and BMI. In male subjects with PWS, testosterone levels correlated to IL-18

Kallmann syndrome and ichthyosis: a case of contiguous gene deletion syndrome

Kallmann syndrome is a genetically heterogeneous form of hypogonadotropic hypogonadism caused by gonadotropin-releasing hormone deficiency and characterized by anosmia or hyposmia due to hypoplasia of the olfactory bulbs; osteoporosis and metabolic syndrome can develop due to longstanding untreated hypogonadism. Kallmann syndrome affects 1 in 10 000 men and 1 in 50 000 women. Defects in 17 genes, including KAL1, have been implicated. Kallmann syndrome can be associated with X-linked ichthyosis, a skin disorder characterized by early onset dark, dry, irregular scales affecting the limb and trunk, caused by a defect of the steroid sulfatase gene (STS). Both KAL1 and STS are located in the Xp22.3 region; therefore, deletions in this region cause a contiguous gene syndrome. We report the case of a 32-year-old man with ichthyosis referred for evaluation of excessive height (2.07 m) and weight (BMI: 29.6 kg/m2), microgenitalia and absence of secondary sex characteristics. We diagnosed Kallmann syndrome with ichthyosis due to a deletion in Xp22.3, a rare phenomenon

Growth Hormone (GH) Treatment Decreases Plasma Kisspeptin Levels in GH-Deficient Adults with Prader–Willi Syndrome

Obesity and growth hormone (GH)-deficiency are consistent features of Prader–Willi syndrome (PWS). Centrally, kisspeptin is involved in regulating reproductive function and can stimulate hypothalamic hormones such as GH. Peripherally, kisspeptin signaling influences energy and metabolic status. We evaluated the effect of 12-month GH treatment on plasma kisspeptin levels in 27 GH-deficient adult PWS patients and analyzed its relationship with metabolic and anthropometric changes. Twenty-seven matched obese subjects and 22 healthy subjects were also studied. Before treatment, plasma kisspeptin concentrations in PWS and obese subjects were similar (140.20 (23.5–156.8) pg/mL vs. 141.96 (113.9–165.6) pg/mL, respectively, p = 0.979)) and higher (p = 0.019) than in healthy subjects (124.58 (107.3–139.0) pg/mL); plasma leptin concentrations were similar in PWS and obese subjects (48.15 (28.80–67.10) ng/mL vs. 33.10 (20.50–67.30) ng/mL, respectively, p = 0.152) and higher (p &lt; 0.001) than in healthy subjects (14.80 (11.37–67.30) ng/mL). After GH therapy, lean body mass increased 2.1% (p = 0.03), total fat mass decreased 1.6% (p = 0.005), and plasma kisspeptin decreased to levels observed in normal-weight subjects (125.1(106.2–153.4) pg/mL, p = 0.027). BMI and leptin levels remained unchanged. In conclusion, 12-month GH therapy improved body composition and decreased plasma kisspeptin in GH deficient adults with PWS. All data are expressed in median (interquartile range)

Cerebellar Dysfunction in Adults with Prader Willi Syndrome

Severe hypotonia during infancy is a hallmark feature of Prader Willi syndrome (PWS). Despite its transient expression, moto development is delayed and deficiencies in motor coordination are present at older ages, with no clear pathophysiological mechanism yet identified. The diverse motor coordination symptoms present in adult PWS patients could be, in part, the result of a common alteration(s) in basic motor control systems. We aimed to examine the motor system in PWS using functional MRI (fMRI) during motor challenge. Twenty-three adults with PWS and 22 matched healthy subjects participated in the study. fMRI testing involved three hand motor tasks of different complexity. Additional behavioral measurements of motor function were obtained by evaluating hand grip strength, functional mobility, and balance. Whole brain activation maps were compared between groups and correlated with behavioral measurements. Performance of the motor tasks in PWS engaged the neural elements typically involved in motor processing. While our data showed no group differences in the simplest task, increasing task demands evoked significantly weaker activation in patients in the cerebellum. Significant interaction between group and correlation pattern with measures of motor function were also observed. Our study provides novel insights into the neural substrates of motor control in PWS by demonstrating reduced cerebellar activation during movement coordination