Transient pituitary ACTH-dependent Cushing syndrome caused by an immune checkpoint inhibitor combination.

Immune checkpoint inhibitors have improved survival in numerous advanced malignancies, but are associated with a number of immune-related adverse events, including endocrinopathies. Endogenous Cushing's syndrome (CS) is a rare disorder resulting from exposure to high levels of circulating cortisol. CS can be caused either by adrenal cortex tumors or hyperplasia or by pituitary or extra-pituitary tumors over-secreting ACTH (known as ACTH-dependent CS). We report the first case of transient ACTH-dependent CS, which appeared after combined ipilimumab and nivolumab therapy. Our patient presented typical clinical features of CS after three infusions of combined therapy, high serum and daily urinary free cortisol, and high serum ACTH levels. Pituitary MRI showed an enlargement of the pituitary gland suggesting ACTH secretion of pituitary origin, which was confirmed by inferior petrosal sinus sampling. The pituitary findings were preceded by thyroiditis. The evolution was characterized by spontaneous CS regression and subsequent appearance of severe corticotroph deficiency consistent with destructive hypophysitis. Immunotherapy is a novel cause of CS.

The burden and treatment of diabetes in France.

BACKGROUND: The objective of this review was to describe and situate the burden and treatment of diabetes within the broader context of the French health care system. METHODS: Literature review on the burden, treatment and outcomes of diabetes in France, complemented by personal communication with with diabetes experts in the Paris public hospital system. RESULTS: Prevalence of diabetes in the French population is estimated at 6%. Diabetes has the highest prevalence among all chronic conditions covered 100% by France's statutory health insurance (SHI), and the number of covered patients has doubled in the past 10 years. In 2010, the SHI cost for pharmacologically-treated diabetes patients amounted to €17.7 billion, including an estimated €2.5 billion directly related to diabetes treatment and prevention and €4.2 billion for treatment of diabetes-related complications. In 2007, the average annual SHI cost was €6 930 for patients with type 1 diabetes and €4 890 for patients with type 2 diabetes. Complications are associated with significantly increased costs. Diabetes is a leading cause of adult blindness, amputation and dialysis in France, which also has one of the highest rates of end-stage renal disease in Europe. Cardiovascular disease is the leading cause of death among people with diabetes. Historically, the French health care system has been more oriented to curative acute care rather than preventive medicine and management of long-term chronic diseases. More recently, the government has focused on primary prevention as part of its national nutrition and health program, with the goal of reducing overweight and obesity in adults and children. It has also recognized the critical role of the patient in managing chronic diseases such as diabetes and has put into place a free patient support program called "sophia". Additional initiatives focus on therapeutic patient education (TPE) and the development of personalized patient pathways. CONCLUSIONS: While France has been successful in protecting patients from the financial consequences of diabetes through its SHI coverage, improvements are necessary in the areas of prevention, monitoring and reducing the incidence of complications. Systemic changes must be made to improve the coordination and delivery of chronic care.

Insulin enhances glucose-stimulated insulin secretion in healthy humans.

Islet beta-cells express both insulin receptors and insulin-signaling proteins. Recent evidence from rodents in vivo and from islets isolated from rodents or humans suggests that the insulin signaling pathway is physiologically important for glucose sensing. We evaluated whether insulin regulates beta-cell function in healthy humans in vivo. Glucose-induced insulin secretion was assessed in healthy humans following 4-h saline (low insulin/sham clamp) or isoglycemic-hyperinsulinemic (high insulin) clamps using B28-Asp insulin that could be immunologically distinguished from endogenous insulin. Insulin and C-peptide clearance were evaluated to understand the impact of hyperinsulinemia on estimates of beta-cell function. Preexposure to exogenous insulin increased the endogenous insulin secretory response to glucose by approximately 40%. C-peptide response also increased, although not to the level predicted by insulin. Insulin clearance was not saturated at hyperinsulinemia, but metabolic clearance of C-peptide, assessed by infusion of stable isotope-labeled C-peptide, increased modestly during hyperinsulinemic clamp. These studies demonstrate that insulin potentiates glucose-stimulated insulin secretion in vivo in healthy humans. In addition, hyperinsulinemia increases C-peptide clearance, which may lead to modest underestimation of beta-cell secretory response when using these methods during prolonged dynamic testing.

Iatrogenic Cushing's syndrome in HIV-infected patients receiving ritonavir and inhaled fluticasone: description of 4 new cases and review of the literature.

Protease inhibitors boosted with ritonavir can lead to drug-drug interactions, particularly with inhaled corticosteroids such as fluticasone, because of the potent inhibition of cytochrome P450-3A4 activity. We report 4 cases of iatrogenic Cushing's syndrome after concomitant administration of inhaled fluticasone and antiretroviral therapy including a protease inhibitor boosted with ritonavir. Although typical manifestations were present, diagnosis of Cushing's syndrome was delayed because the patients were suspected to have antiretroviral therapy-associated lipodystrophy, which shares common clinical features with Cushing's syndrome. Biochemical tests confirmed iatrogenic Cushing's syndrome and clinical symptoms resolved after stopping ritonavir or fluticasone. The differences between the clinical symptoms of Cushing's syndrome and lipodystrophy are discussed as well as their frequency in the cases reported in the literature. The recommendation that concomitant administration of inhaled or intranasal fluticasone and ritonavir be prohibited must be implemented among practitioners who treat HIV-infected patients, and if long-term inhaled steroids are required, other drugs should be preferred.

The common -866G>A variant in the promoter of UCP2 is associated with decreased risk of coronary artery disease in type 2 diabetic men.

OBJECTIVE: Uncoupling protein 2 (UCP2) is a physiological downregulator of reactive oxygen species generation and plays an antiatherogenic role in the vascular wall. A common variant in the UCP2 promoter (-866G>A) modulates mRNA expression, with increased expression associated with the A allele. We investigated association of this variant with coronary artery disease (CAD) in two cohorts of type 2 diabetic subjects. RESEARCH DESIGN AND METHODS: We studied 3,122 subjects from the 6-year prospective Non-Insulin-Dependent Diabetes, Hypertension, Microalbuminuria, Cardiovascular Events, and Ramipril (DIABHYCAR) Study (14.9% of CAD incidence at follow-up). An independent, hospital-based cohort of 335 men, 52% of whom had CAD, was also studied. RESULTS: We observed an inverse association of the A allele with incident cases of CAD in a dominant model (hazard risk 0.88 [95% CI 0.80-0.96]; P = 0.006). Similar results were observed for baseline cases of CAD. Stratification by sex confirmed an allelic association with CAD in men, whereas no association was observed in women. All CAD phenotypes considered--myocardial infarction, angina pectoris, coronary artery bypass graft (CABG), and sudden death--contributed significantly to the association. Results were replicated in a cross-sectional study of an independent cohort (odds ratio 0.47 [95% CI 0.25-0.89]; P = 0.02 for a recessive model). CONCLUSIONS: The A allele of the -866G>A variant of UCP2 was associated with reduced risk of CAD in men with type 2 diabetes in a 6-year prospective study. Decreased risk of myocardial infarction, angina pectoris, CABG, and sudden death contributed individually and significantly to the reduction of CAD risk. This association was independent of other common CAD risk factors.

The cellular fate of glucose and its relevance in type 2 diabetes.

Type 2 diabetes is a complex disorder with diminished insulin secretion and insulin action contributing to the hyperglycemia and wide range of metabolic defects that underlie the disease. The contribution of glucose metabolic pathways per se in the pathogenesis of the disease remains unclear. The cellular fate of glucose begins with glucose transport and phosphorylation. Subsequent pathways of glucose utilization include aerobic and anaerobic glycolysis, glycogen formation, and conversion to other intermediates in the hexose phosphate or hexosamine biosynthesis pathways. Abnormalities in each pathway may occur in diabetic subjects; however, it is unclear whether perturbations in these may lead to diabetes or are a consequence of the multiple metabolic abnormalities found in the disease. This review is focused on the cellular fate of glucose and relevance to human type 2 diabetes.

Beta-cell insulin secretory response to oral hypoglycemic agents is blunted in humans in vivo during moderate hypoglycemia.

Oral hypoglycemic agents bind to the ATP-sensitive potassium channel and lower glucose levels effectively in individuals with diabetes. Although the principle mechanism of action can also promote hypoglycemia, clinically profound hypoglycemia is rare. Decreased stimulation of insulin secretion by these agents at mild hypoglycemia could provide protection from more profound hypoglycemia. Sulfonylureas and meglitinides bind to both shared and unique sites on the ATP-sensitive potassium receptor/channel complex but have different pharmacokinetic profiles. To evaluate the differential ability of both sulfonylureas and meglitinides to stimulate insulin release at modest hypoglycemia, we evaluated dextrose infusion rates necessary to maintain plasma glucose after oral administration of repaglinide (1 mg) or glipizide (5 mg) at euglycemia and again at modest hypoglycemia. Healthy subjects with no family history of diabetes underwent four clamp studies, two performed while maintaining isoglycemia (glucose levels at the fasted value) and two while maintaining modest hypoglycemia of 2.78 mmol/liter (50 mg/dl) induced by low-dose insulin infusion (3.6 pmol/kg.min). There was a marked decrease in the dextrose infusion rate with administration of either repaglinide or glipizide at hypoglycemia compared with drug administration at euglycemia (P

Insulin resistance is a poor predictor of type 2 diabetes in individuals with no family history of disease.

In normoglycemic offspring of two type 2 diabetic parents, low insulin sensitivity (S(I)) and low insulin-independent glucose effectiveness (S(G)) predict the development of diabetes one to two decades later. To determine whether low S(I), low S(G,) or low acute insulin response to glucose are predictive of diabetes in a population at low genetic risk for disease, 181 normoglycemic individuals with no family history of diabetes (FH-) and 150 normoglycemic offspring of two type 2 diabetic parents (FH+) underwent i.v. glucose tolerance testing (IVGTT) between the years 1964-82. During 25 +/- 6 years follow-up, comprising 2,758 person years, the FH- cohort (54 +/- 9 years) had an age-adjusted incidence rate of type 2 diabetes of 1.8 per 1,000 person years, similar to that in other population-based studies, but significantly lower than 16.7 for the FH+ cohort. Even when the two study populations were subdivided by initial values of S(I) and S(G) derived from IVGTT's performed at study entry, there was a 10- to 20-fold difference in age-adjusted incidence rates for diabetes in the FH- vs. FH+ individuals with low S(I) and low S(G). The acute insulin response to glucose was not predictive of the development of diabetes when considered independently or when assessed as a function of S(I), i.e., the glucose disposition index. These data demonstrate that low glucose disposal rates are robustly associated with the development of diabetes in the FH+ individuals, but insulin resistance per se is not sufficient for the development of diabetes in individuals without family history of disease and strongly suggest a familial factor, not detectable in our current measures of the dynamic responses of glucose or insulin to an IVGTT is an important risk factor for type 2 diabetes. Low S(I) and low S(G), both measures of glucose disposal, interact with this putative familial factor to result in a high risk of type 2 diabetes in the FH+ individuals, but not in the FH- individuals.

Five-week, low-glycemic index diet decreases total fat mass and improves plasma lipid profile in moderately overweight nondiabetic men.

OBJECTIVE: To evaluate whether a 5-week low-glycemic index (LGI) diet versus a high-glycemic index (HGI) diet can modify glucose and lipid metabolism as well as total fat mass in nondiabetic men. RESEARCH DESIGN AND METHODS: In this study, 11 healthy men were randomly allocated to 5 weeks of an LGI or HGI diet separated by a 5-week washout interval in a crossover design. RESULTS: The LGI diet resulted in lower postprandial plasma glucose and insulin profiles and areas under the curve (AUCs) than the HGI diet. A 5-week period of the LGI diet lowered plasma triacylglycerol excursion after lunch (AUC, P < 0.05 LGI vs. HGI). These modifications were associated with a decrease in the total fat mass by approximately 700 g (P < 0.05) and a tendency to increase lean body mass (P < 0.07) without any change in body weight. This decrease in fat mass was accompanied by a decrease in leptin, lipoprotein lipase, and hormone-sensitive lipase RNAm quantities in the subcutaneous abdominal adipose tissue (P < 0.05). CONCLUSIONS: We concluded that 5 weeks of an LGI diet ameliorates some plasma lipid parameters, decreases total fat mass, and tends to increase lean body mass without changing body weight. These changes were accompanied by a decrease in the expression of some genes implicated in lipid metabolism. Such a diet could be of benefit to healthy, slightly overweight subjects and might play a role in the prevention of metabolic diseases and their cardiovascular complications.