Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ghrelin, a novel GH-releasing peptide isolated from human and rat stomach, stimulates food intake and GH secretion. We determined plasma ghrelin concentrations in patients with simple obesity, anorexia nervosa, and type 2 diabetes mellitus by RIA. We also studied plasma ghrelin responses to glucose load and meal intake and obtained a 24-h profile of circulating ghrelin in humans. Plasma ghrelin concentrations in patients with simple obesity and anorexia nervosa were lower and higher, respectively, than those of healthy subjects with normal body weight. Among those with type 2 diabetes mellitus, obese patients had lower and lean patients higher fasting plasma ghrelin concentrations than normal-weight patients. Fasting plasma ghrelin concentration was negatively correlated with body mass index in both nondiabetic and diabetic patients. Plasma ghrelin concentrations of normal subjects decreased significantly after oral and iv glucose administration; a similar response was also observed in diabetic patients after a meal tolerance test, reaching a nadir of 69% of the basal level after the meal. Circulating plasma ghrelin showed a diurnal pattern with preprandial increases, postprandial decreases, and a maximum peak at 0200 h. This study demonstrates that nutritional state is a determinant of plasma ghrelin in humans. Ghrelin secretion is up-regulated under conditions of negative energy balance and down-regulated in the setting of positive energy balance. These findings suggest the involvement of ghrelin in the regulation of feeding behavior and energy homeostasis.
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PMID:Plasma ghrelin levels in lean and obese humans and the effect of glucose on ghrelin secretion. 1178 53

Adipocytal hormones resistin and adiponectin and gastric peptide ghrelin are recently discovered hormones, which are considered to take part in energy metabolism regulation. Resistin is expressed in adipose tissue only and its increased levels could cause insulin resistance and thus link obesity with type 2 diabetes. Adiponectin, as well as resistin, are products of genes, expressed in adipose tissue. Adiponectin could prevent development of aterosclerosis and it could play a role in anti-inflammatory reactions. Ghrelin is produced mainly in the stomach. Beside its role in long-term regulation of energy metabolism, it is involved in the short-term regulation of feeding. Main roles of resistin, adiponectin and ghrelin are summarised in the presented overview.
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PMID:[Recently discovered hormones with a role in energy homeostasis]. 1269 33

Experimental studies have suggested that ghrelin plays a role in glucose homeostasis and in the regulation of blood pressure (BP). We therefore assessed the hypothesis that a low ghrelin concentration may be a risk factor for type 2 diabetes and hypertension. We also characterized the effect of the ghrelin Arg51Gln and Leu72Met mutations on ghrelin concentrations in the population-based hypertensive (n = 519) and control (n = 526) cohorts of our OPERA (Oulu Project Elucidating Risk of Atherosclerosis) study. The fasting plasma ghrelin concentrations of 1,040 subjects were analyzed using the radioimmunoassay method. Insulin sensitivity was assessed using the quantitative insulin sensitivity check index (QUICKI). Ghrelin concentrations were negatively associated with fasting insulin (P < 0.001), systolic (P = 0.026) and diastolic BP (P = 0.018), and the prevalence of type 2 diabetes (P = 0.015) and insulin resistance (P < 0.001) in the multivariate models. In the control cohort, low ghrelin was associated with hypertension (BP >140/90 mmHg) (P = 0.031). The subjects with the ghrelin 51Gln allele had lower ghrelin concentrations than the Arg51Arg homozygotes (P = 0.001). We conclude that low ghrelin is independently associated with type 2 diabetes, insulin concentration, insulin resistance, and elevated BP. Therefore, it might have some role in the etiology of type 2 diabetes and the regulation of BP. The ghrelin Arg51Gln mutation is associated with low plasma ghrelin concentrations.
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PMID:Low plasma ghrelin is associated with insulin resistance, hypertension, and the prevalence of type 2 diabetes. 1451 39

Ghrelin, isolated from the human and rat stomach, is the endogenous ligand for the growth hormone (GH) secretagogue receptor, which is expressed in a variety of tissues, including the pancreatic islets. It has been shown that low plasma ghrelin levels correlates with elevated fasting insulin levels and type 2 diabetes. Here we show a physiological role of endogenous ghrelin in the regulation of insulin release and blood glucose in rodents. Acylated ghrelin, the active form of the peptide, was detected in the pancreatic islets. Counteraction of endogenous ghrelin by intraperitoneal injection of specific GH secretagogue receptor antagonists markedly lowered fasting glucose concentrations, attenuated plasma glucose elevation, and enhanced insulin responses during the glucose tolerance test (GTT). Conversely, intraperitoneal exogenous ghrelin GH-independently elevated fasting glucose concentrations, enhanced plasma glucose elevation, and attenuated insulin responses during GTT. Neither GH secretagogue receptor antagonist nor ghrelin affected the profiles of the insulin tolerance test. In isolated islets, GH secretagogue receptor blockade and antiserum against acylated ghrelin markedly enhanced glucose-induced increases in insulin release and intracellular Ca2+ concentration ([Ca2+]i), whereas ghrelin at a relatively high concentration (10 nmol/l) suppressed insulin release. In single beta-cells, ghrelin attenuated glucose-induced first-phase and oscillatory [Ca2+]i increases via the GH secretagogue receptor and in a pertussis toxin-sensitive manner. Ghrelin also increased tetraethylammonium-sensitive delayed outward K+ currents in single beta-cells. These findings reveal that endogenous ghrelin in islets acts on beta-cells to restrict glucose-induced insulin release at least partly via attenuation of Ca2+ signaling, and that this insulinostatic action may be implicated in the upward control of blood glucose. This function of ghrelin, together with inducing GH release and feeding, suggests that ghrelin underlies the integrative regulation of energy homeostasis.
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PMID:Endogenous ghrelin in pancreatic islets restricts insulin release by attenuating Ca2+ signaling in beta-cells: implication in the glycemic control in rodents. 1556 44

There is a strong association between low birth weight and insulin resistance. The thrifty phenotype hypothesis, which postulates fetal programming for adaptation to an adverse intrauterine environment, resulting in a lower insulin sensitivity in utero, is one of the hypothesis to explain this association. Later in life, syndrome X may develop, featuring hypertension, dyslipidemia, central obesity and type 2 diabetes, associated to an excessive food intake. Our investigation during the first three years of life in a prospective cohort of small (SGA) or appropriate for gestational age newborns, demonstrated that a significant increase of insulin levels is detected in SGA, as early as during the first year of life, but only when catch up growth (CUG) occurs. Orexigenic peptides such as Ghrelin appear to participate in this CUG phenomenon. We also sought to determine whether these associations were observed in individuals born with very low birth weight. We found that in utero as well as postnatal growth rates were independent determinants of insulin sensitivity and secretion. Education about feeding practices and physical activity in SGA children, is a future challenge to prevent the onset of syndrome X in this predisposed population.
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PMID:[Fetal growth restriction and insulin resistance. New findings and review of the literature]. 1576 56

1. In the present study, we sought to determine whether physiological or pathophysiological concentrations of obesity related peptides influence the key early atherogenic events of monocyte adhesion to endothelial cells and adhesion molecule expression using primary human cells. 2. Human umbilical vein endothelial cells were grown to confluence and human monocytes were obtained by elutriation. Adhesion was assessed by automated cell counting and cell adhesion molecule expression (E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1)) was assayed by ELISA. 3. Experimental conditions included untreated control, ghrelin (100, 150, 450 and 1350 pmol/L), resistin (15, 40 and 100 ng/mL) and combined leptin and insulin (combinations of 30 and 120 pmol/L insulin and 5, 50 and 500 ng/mL leptin). 4. Both resistin and ghrelin produced modest but significant increases in VCAM-1 expression (110 +/- 4 and 117 +/- 13% compared with controls, respectively; both P <or= 0.01). Ghrelin also increased ICAM-1 expression (119 +/- 17% of control; P <or= 0.01). 5. However, despite these increases in adhesion molecule expression, neither ghrelin nor resistin altered monocyte adhesion values. 6. Neither leptin nor insulin altered monocyte adhesion to endothelial cells or cell adhesion molecule expression. 7. Pathophysiologically relevant concentrations of ghrelin and resistin, within the range of concentrations exhibited by patients with anorexia nervosa or the Prader-Willi syndrome and type 2 diabetes, respectively, increase endothelial cell adhesion molecule expression, possibly contributing to increased atherosclerosis risk in such subjects.
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PMID:Pathophysiological levels of the obesity related peptides resistin and ghrelin increase adhesion molecule expression on human vascular endothelial cells. 1617 45

Obesity is a multi-gene syndrome, expression of which is modulated not only by environmental factors but above all by a number of modified genes interacting with each other. Among candidate genes related to obesity phenotype is ghrelin gene. Ghrelin plays a significant role in feeding regulation and is the strongest stimulator of growth hormone secretion. Ghrelin acts by GHS1a receptor (growth hormone secretagogue receptor). Mutations in preproghrelin and ghrelin gene or ghrelin receptor gene could be responsible for low ghrelin levels observed in obese individuals. Among identificated mutations, two Arg51 Gln and Leu72Met are most often described and change amino-acid sequence of ghrelin (Arg51Gln) and preproghrelin (Leu72Met). Although no direct relationship between Arg51Gln mutation and obesity phenotype was found, it had been shown that carriers of Arg51Gln mutation had significantly decreased plasma ghrelin levels. Furthermore 51Gln allele carriers had higher prevalence of type 2 diabetes mellitus and hypertension than non-carriers. Met 72 carrier status is associated with higher serum IGF-1 levels and seems to be a protective factor against fat accumulation and cardiovascular complications of obesity. No evidence of relationship between ghrelin receptor gene polymorphisms and body mass regulation was found, however, until now there is no study on relationships between these polymorphisms and metabolic complications of obesity. The presence of genetic variants in ghrelin or GHS receptor gene could be responsible for impaired GH secretion in visceral type obesity and development of metabolic syndrome in some of obese subjects. On the other hand, some mutations in preproghrelin gene could be protective against metabolic syndrome.
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PMID:[Preproghrelin gene, ghrelin receptor and metabolic syndrome]. 1622 41

Ghrelin is a 28 aminoacids peptide secreted from the stomach that stimulates the release of growth hormone (GH) from the anterior pituitary cells and is the strongest orexigenic hormone discovered so far. Ghrelin seems to be involved in the pathogenesis of obesity, anorexia nervosa and cachexia. Furthermore, low levels of ghrelin are negatively correlated with the degree of insulin resistance, blood pressure and the prevalence of type 2 diabetes. The role of ghrelin in the energy homeostasis and carbohydrate metabolism is discussed.
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PMID:[Ghrelin--role in energy homeostasis and glucose metabolism]. 1623 72

Ghrelin is a novel gut-brain peptide, which exerts somatotropic, orexigenic, and adipogenic effects. Genetic variants of ghrelin have been associated with both obesity and insulin metabolism. In this study, we determined a role of preproghrelin Leu72Met polymorphism on type 2 diabetes mellitus and its relationship to variables studied. Genotypes were assessed by polymerase chain reaction. Frequencies of the Leu72Met polymorphism were found to be 35.4% in the type 2 diabetic patients and 32.5% in the normal controls. The Leu72Met polymorphism was not associated with hypertension, macroangiopathy, retinopathy, serum cholesterol, triglyceride, blood urea nitrogen, HbA(1c), lipoprotein (a), fasting insulin, or 24-hour urinary protein levels in the type 2 diabetic group. However, the Leu72Met polymorphism was clearly associated with serum creatinine levels in the diabetic group, as the Met72 carriers exhibited lower serum creatinine levels than the Met72 noncarriers. Our data indicate that the preproghrelin Leu72Met polymorphism is not associated with type 2 diabetes mellitus. However, the Leu72Met polymorphism is associated with serum creatinine levels. These data suggest that Met72 carrier status may be a predictable marker for diabetic nephropathy or renal impairment in type 2 diabetes mellitus.
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PMID:Preproghrelin Leu72Met polymorphism is not associated with type 2 diabetes mellitus. 1648 81

Ghrelin is a 28-amino-acid peptide with several functions linked to energy metabolism. Low ghrelin plasma concentrations are associated with obesity, hypertension, and type 2 diabetes mellitus, whereas high concentrations reflect states of negative energy balance. Several studies addressing the hormonal and neural regulation of ghrelin gene expression have been carried out, but the role of genetic factors in the regulation of ghrelin plasma levels remains unclear. To elucidate the role of genetic factors in the regulation of ghrelin expression, we screened 1657 nucleotides of the ghrelin gene 5' flanking region (promoter and possible regulatory sites) for new sequential variations from patient samples with low (n = 50) and high (n = 50) fasting plasma total ghrelin concentrations (low- and high-ghrelin groups). Eleven single nucleotide polymorphisms (SNPs), 3 of which were rare variants (allelic frequency less than 1%) were found in our population. The genotype distribution patterns of the SNPs did not differ between the study groups, except for SNP-501A>C (P = .039). In addition, the SNP-01A>C was associated with body mass index (BMI) (P = .018). This variant was studied further in our large and well-defined Oulu Project Elucidating Risk for Atherosclerosis (OPERA) cohort (n = 1045) by the restriction fragment length polymorphism (RFLP) technique. No significant association of SNP-501A>C genotypes with fasting ghrelin plasma concentrations was found in the whole OPERA population. However, the association of this SNP with BMI and with waist circumference reached statistical significance in OPERA (P = .047 and .049, respectively), remaining of borderline significance for BMI after adjustments (P = .055). The results indicate that factors other than the 11 SNPs found in this study in the 5' flanking region of ghrelin gene are the main determinants of ghrelin plasma levels. However, SNP-501 A>C genotype distribution seems to be different in subjects having the highest compared with those with the lowest ghrelin levels, and the SNP may be associated with BMI and waist circumference.
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PMID:Sequencing analysis of ghrelin gene 5' flanking region: relations between the sequence variants, fasting plasma total ghrelin concentrations, and body mass index. 1855 45


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