In patients with type 2 diabetes who were at high cardiovascular risk, the rate of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke was significantly lower among patients receiving semaglutide than among those receiving placebo, an outcome that confirmed the noninferiority of semaglutide. (Funded by Novo Nordisk; SUSTAIN-6 ClinicalTrials.gov number, NCT01720446 .).
Background: Glucagon-like peptide 1 agonists differ in chemical structure, duration of action and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. Methods: We randomly assigned patients with type 2 diabetes and cardiovascular disease to the addition of once-weekly subcutaneous injection of albiglutide (30 mg to 50 mg) or matching placebo to standard care. We hypothesized that albiglutide would be noninferior to placebo for the primary outcome of first occurrence of cardiovascular death, myocardial infarction, or stroke. If noninferiority was confirmed by an upper limit of the 95% confidence interval for the hazard ratio of less than 1.30, closed-testing for superiority was prespecified. Findings: Overall, 9463 participants were followed for a median of 1.6 years. The primary composite outcome occurred in 338 of 4731 patients (7.1%; 4.6 events per 100 person-years) in the albiglutide group and in 428 of 4732 patients (9.0%; 5.9 events per 100 person-years) in the placebo group (hazard ratio, 0.78; 95% confidence interval [CI ], 0.68 to 0.90), indicating that albiglutide, was superior to placebo (P<0.0001 for noninferiority, P=0.0006 for superiority). The incidence of acute pancreatitis (albiglutide 10 patients and placebo 7 patients), pancreatic cancer (6 and 5), medullary thyroid carcinoma (0 and 0), and other serious adverse events did not differ significantly between the two groups. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. (Funded by GlaxoSmithKline; Harmony Outcomes ClinicalTrials.gov number, NCT02465515.) noninferiority; P = 0.06 for superiority). There seems to be variation in the results of existing trials with GLP-1 receptor agonists, which if correct, might reflect drug structure or duration of action, patients studied, duration of follow-up or other factors.
Irisin is a myokine that leads to increased energy expenditure by stimulating the ‘browning’ of white adipose tissue. In the first description of this hormone, increased levels of circulating irisin, which is cleaved from its precursor fibronectin type III domain-containing protein 5, were associated with improved glucose homeostasis by reducing insulin resistance. Consequently, several studies attempted to characterize the role of irisin in glucose regulation, but contradictory results have been reported, and even the existence of this hormone has been questioned. In this Review, we present the current knowledge on the physiology of irisin and its role in glucose homeostasis. We describe the mechanisms involved in the synthesis, secretion, circulation and regulation of irisin, and the controversies regarding the measurement of irisin. We also discuss the direct effects of irisin on glucose regulatory mechanisms in different organs, the indirect effects and interactions with other hormones, and the important open questions with regard to irisin in those organs. Finally, we present the results from animal interventional studies and from human clinical studies investigating the association of irisin with obesity, insulin resistance, type 2 diabetes mellitus and the metabolic syndrome.
To detect morphologic abnormalities in Parkinson's disease (PD), we examined 30 patients with PD and 30 age- and sex-matched nonparkinsonian controls by transcranial color-coded real-time sonography (TCCS). In 12 severely affected PD patients, the echogenicity of the substantia nigra was distinctly increased. In the remaining 18 PD patients and in all controls, the substantia nigra was poorly visualized or nondetectable by TCCS. The degree of hyperechogenicity of the substantia nigra closely correlated with the severity and duration of PD (p < 0.001). The increased echogenicity of the substantia nigra notably results from nigral gliosis and reflects the stage of degeneration.
The hormone leptin is secreted from white adipocytes, and serum levels of leptin correlate with adipose tissue mass. Leptin was first described to act on the satiety center in the hypothalamus through specific receptors (leptin receptor [
Previously we demonstrated the expression of the long form of the leptin receptor in rodent pancreatic β-cells and an inhibition of insulin secretion by leptin via activation of ATP-sensitive potassium channels. Here we examine pancreatic islets isolated from pancreata of human donors for their responses to leptin. The presence of leptin receptors on islet β-cells was demonstrated by double fluorescence confocal microscopy after binding of a fluorescent derivative of human leptin (Cy3-leptin). Leptin (6.25 nM) suppressed insulin secretion of normal islets by 20% at 5.6 mM glucose. Intracellular calcium responses to 16.7 mM glucose were rapidly reduced by leptin. Proinsulin messenger ribonucleic acid expression in islets was inhibited by leptin at 11.1 mM, but not at 5.6 mM glucose. Leptin also reduced proinsulin messenger ribonucleic acid levels that were increased in islets by treatment with 10 nM glucagon-like peptide-1 in the presence of either 5.6 or 11.1 mM glucose. These findings demonstrate direct suppressive effects of leptin on insulinproducing β-cells in human islets at the levels of both stimulus-secretion coupling and gene expression. The findings also further indicate the existence of an adipoinsular axis in humans in which insulin stimulates leptin production in adipocytes and leptin inhibits the production of insulin in β-cells. We suggest that dysregulation of the adipoinsular axis in obese individuals due to defective leptin reception by β-cells may result in chronic hyperinsulinemia and may contribute to the pathogenesis of adipogenic diabetes.Obesity and associated diabetes are epidemic throughout the world. The prevalence of morbid obesity is between 20-40% in populations of developing countries and predisposes to the development of diabetes, so-called adipogenic diabetes (1,2). Moreover, obese individuals characteristically manifest insulin resistance and hyperinsulinemia, which predispose to glucose intolerance, diabetes, and cardiovascular disease (1). From 50-80% of subjects worldwide with diabetes are obese depending upon the ethnic background and the community (3-8). It has been estimated that for every kilogram of increase in weight, the risk for diabetes increases 4.5% (9). Remarkably, 97 million American adults (35% of the population) are overweight or obese (10). The marked increase in the prevalence of obesity is believed to be due in large part to a change in life-style favoring excessive caloric intake and a sedentary existence (11).A major advance in understanding the hormonal causation of morbid obesity is the discovery of a hormone, leptin, produced by adipose tissue that modifies feeding behavior in rodents as a potent suppressor of food intake and stimulator of energy expenditure (12,13). Leptin exerts its actions centrally on appetite and thermogenic control centers located in the hypothalamus. It is important to note that obesity in humans is believed to be due to a desensitization of leptin reception within the hypothalamus, resulting in hyperphagia (1,(12)(13)(14...
Our data indicate a high prevalence of comorbidities in patients with PA. The hypokalemic variant is defined by a higher morbidity than the normokalemic variant regarding some cardiovascular but not cerebrovascular events. Thus, PA should be sought not only in hypokalemic but also in normokalemic hypertensives because high-excess morbidity occurs in both subgroups.
In a large cohort of patients with PA, markers of disease activity such as plasma aldosterone and serum potassium are independent predictors of a lower GFR. Specific interventions, such as adrenalectomy or spironolactone treatment, are associated with a further decline in GFR.
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