Fasting ghrelin but not PYY(3-36) is associated with insulin-resistance independently of body weight in Wistar rats / A grelina, mas não PYY(3-36), está associada com a resistência à insulina independente do peso corporal em ratos Wistar

Objective: The objective of this study was to evaluate the association between insulin-resistance and fasting levels of ghrelin and PYY in Wistar rats. Materials and methods: A total of 25 male Wistar rats, weighing 200-300 g, was included in this study. The animals were maintained in cages with a 12/12h light-dark cycle and fed standard chow and water ad libitum. After 12-h overnight fasting, ghrelin, PYY, insulin and glucose values were determined. Insulin resistance was assessed by means of the HOMA-IR, which was ranked and the median was used as a cut-off value to categorize insulin-resistance. HOMA-IR values equal and above 2.62 were considered insulin-resistant (IR) while values below 2.62 were considered insulin sensitive (IS). Differences between means were determined using the Student t-test. Multiple regression and Pearson’s correlation test were used to evaluate the association between variables. Results: HOMA-IR median IQ range values for IS and IR groups were, respectively, 1.56 (0.89 – 2.16) vs. [4.06 (3.50 – 4.61); p < 0.001]. The IR group presented increased levels of fasting ghrelin, PYY and insulin respectively: [50.35 (25.99 – 74.71) pg/mL vs. 12.33 (8.77 – 15.89) pg/mL; p = 0.001]; [54.38 (37.50 – 71.26) pg/mL vs. 33.17 (22.34 – 43.99) pg/mL; p = 0.016]; [18.04 (14.48 – 21.60) uU/mL vs. 7.09 (4.83 – 9.35) uU/mL; p = 0.001]. Ghrelin, but not PYY, correlated linearly and positively with HOMA-IR: ghrelin vs. HOMA-IR (r = 0.52; p = 0.008), and PYY vs. HOMA-IR (r = 0.22; p = 0.200). This correlation was independent of body weight. Conclusion: Fasting ghrelin and PYY serum levels are increased in lean, relatively insulin resistant Wistar rats, and this increase is independent of weight. .

Objetivo: O objetivo deste estudo foi avaliar a associação entre a resistência à insulina e os níveis de grelina e PYY em jejum em ratos Wistar. Materiais e métodos: Um total de 25 ratos Wistar machos, pesando 200-300 g, foi usado neste estudo. Os animais foram mantidos em gaiolas com um ciclo de luz escuro de 12/12h e alimentados com ração padrão e água ad libitum. Depois de um jejum de 12h, os valores de grelina, PYY, insulina e glicose foram determinados. A resistência à insulina foi avaliada pelo HOMA-IR que foi ordenado e a mediana utilizada como valor de corte para categorizar a resistência à insulina. Os valores de HOMA-IR iguais ou acima de 2,62 foram considerados resistentes à insulina (RI), enquanto valores abaixo de 2,62 foram considerados sensíveis (SI). As diferenças entre as médias foram determinadas usando-se o teste t de Student. A análise de regressões múltiplas e o teste de correlação de Pearson foram usados para se avaliar a associação entre as variáveis. Resultados: A mediana e a variação IQ do HOMA-IR para os grupos RI e SI foram, respectivamente, 1,56 (0,89 – 2,16) contra [4,06 (3,50 – 4,61); p < 0,001]. O grupo RI apresentou níveis aumentados de grelina, PYY e insulina em jejum, respectivamente, [50,35 (25,99 – 74,71) pg/mL contra 12,33 (8,77 – 15,89) pg/mL; p = 0,001]; [54,38 (37,50 – 71,26) pg/mL contra 33,17 (22,34 – 43,99) pg/mL; p = 0,016]; [18,04 (14,48 – 21,60) uU/mL contra 7,09 (4,83 – 9,35) uU/mL; p = 0.001]. A grelina, mas não PYY, se correlacionou de forma linear e positiva com o HOMA-IR: a grelina contra HOMA-IR (r = 0,52; p = 0,008), e PYY contra HOMA-IR (r = 0,22; p = 0,200). Essa correlação foi independente do peso corporal. Conclusão: Os níveis séricos de jejum de grelina ...

Effect of the ingestion of the palm oil and glutamine in serum levels of GLP-1, PYY and glycemia in diabetes mellitus type 2 patients submitted to metabolic surgery / Efeito do óleo de palma e da glutamina nos níveis séricos de GLP-1, PYY e da glicemia em portadores de diabete melito tipo 2 submetidos à cirurgia metabólica

BACKGROUND: Incretins are hormones produced by the intestine and can stimulate the secretion of insulin, helping to diminish the post-prandial glycemia. The administration of an emulsion of palm oil can help in the maintenance of the weight, and can increase circulating incretins levels. Glutamine increases the concentration of incretins in diabetic people. Both can help in metabolic syndrome. AIM: To analyze the effects of ingestion of palm oil and glutamine in glycemia and in incretins in patients with diabetes submitted to surgical duodenojejunal exclusion with ileal interposition without gastrectomy. METHODS: Eleven diabetic type 2 patients were included and were operated. They were called to laboratory follow-up without eating anything between eight and 12 hours. They had there blood collected after the stimulus of the palm oil and glutamine taken in different days. For the hormonal doses were used ELISA kits. RESULTS: The glycemia showed a meaningful fall between the fast and two hours after the stimulus of the palm oil (p=0,018). With the glutamine the GLP-1 showed an increase between the fast and one hour (p=0,32), the PYY showed an important increase between the fast and one hour after the stimulus (p=0,06), the glycemia showed a meaningful fall after two hours of the administration of the stimulus (p=0,03). CONCLUSION: Palm oil and glutamine can influence intestinal peptides and glucose .

RACIONAL: A administração de óleo de palma auxilia na manutenção do peso e aumenta níveis de incretinas circulantes. A glutamina aumenta a concentração de incretinas em indivíduos diabéticos. Assim, eles podem influenciar no tratamento da síndrome metabólica. OBJETIVO: Analisar os efeitos da ingestão de óleo de palma e glutamina na glicemia e incretinas em pacientes diabéticos que foram submetidos à operação de exclusão duodenojejunal com interposição ileal sem gastrectomia. MÉTODOS: Participaram 11 pacientes, portadores de diabete melito tipo 2, que foram operados com exclusão duodenojejunal com interposição ileal sem gastrectomia. Foram convocados para comparecer ao laboratório em jejum de oito a 12 horas e submetidos ao procedimento de coleta de sangue após os estímulos de óleo de palma e glutamina via oral em dias distintos. Para as dosagens hormonais foram utilizados kits de ELISA. RESULTADOS: A glicemia apresentou queda significativa entre o jejum e duas horas após o estímulo de óleo de palma (p=0,018). Com a glutamina, o GLP-1 apresentou aumento entre o jejum e uma hora (p=0,32); o PYY apresentou aumento entre o jejum e uma hora após o estímulo (p=0,06); a glicemia apresentou queda significativa após duas horas da administração do estímulo (p=0,03). CONCLUSÃO: O óleo de palma e a glutamina podem influenciar os peptídeos intestinais e na glicemia .

Correlations of circulating peptide YY and ghrelin with body weight, rate of weight gain, and time required to achieve the recommended daily intake in preterm infants

The objective was to elucidate the relationships between serum concentrations of the gut hormone peptide YY (PYY) and ghrelin and growth development in infants for potential application to the clinical observation index. Serum concentrations of PYY and ghrelin were measured using radioimmunoassay from samples collected at the clinic. For each patient, gestational age, birth weight, time required to return to birth weight, rate of weight gain, time required to achieve recommended daily intake (RDI) standards, time required for full-gastric feeding, duration of hospitalization, and time of administration of total parenteral nutrition were recorded. Serum PYY and ghrelin concentrations were significantly higher in the preterm group (N = 20) than in the full-term group (N = 20; P < 0.01). Within the preterm infant group, the serum concentrations of PYY and ghrelin on postnatal day (PND) 7 (ghrelin = 1485.38 ± 409.24; PYY = 812.37 ± 153.77 ng/L) were significantly higher than on PND 1 (ghrelin = 956.85 ± 223.09; PYY = 545.27 ± 204.51 ng/L) or PND 3 (ghrelin = 1108.44 ± 351.36; PYY = 628.96 ± 235.63 ng/L; P < 0.01). Both serum PYY and ghrelin concentrations were negatively correlated with body weight, and the degree of correlation varied with age. Serum ghrelin concentration correlated negatively with birth weight and positively with the time required to achieve RDI (P < 0.05). In conclusion, serum PYY and ghrelin concentrations reflect a negative energy balance, predict postnatal growth, and enable compensation. Further studies are required to elucidate the precise concentration and roles of PYY and ghrelin in newborns and to determine the usefulness of measuring these hormones in clinical practice.

Peptide YY, Cholecystokinin, Insulin and Ghrelin Response to Meal did not Change, but Mean Serum Levels of Insulin is Reduced in Children with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a contiguous gene syndrome characterized by uncontrollable eating or hyperphagia. Several studies have confirmed that plasma ghrelin levels are markedly elevated in PWS adults and children. The study of anorexigenic hormones is of interest because of their regulation of appetite by negative signals. To study the pattern and response of the anorexigenic hormones such as cholecystokinin (CCK) and peptide YY (PYY) to a meal in PWS, we measured the plasma CCK, PYY, ghrelin and serum insulin levels in PWS patients (n=4) and in controls (n=4) hourly for a day, and analyzed hormone levels and hormonal responses to meals. Repeated measures of ANOVA of hormone levels demonstrated that only insulin levels decreased (p=0.013) and CCK (p=0.005) and ghrelin (p=0.0007) increased in PWS over 24 hr. However, no significant group x time interactions (ghrelin: p=0.89, CCK: p=0.93, PYY: p=0.68 and insulin: p=0.85) were observed; in addition, there were no differences in an assessment of a three-hour area under the curve after breakfast. These results suggest that the response pattern of hormones to meals in PWS patients parallels that of normal controls. In addition, the decrease of insulin levels over 24 hr, in spite of obesity and elevated ghrelin levels, suggests that the baseline insulin level, not the insulin response to meals, may be abnormal in patients with PWS.