Search

ObjectivePulmonary hypertension (PH) due to left heart disease (group 2), especially in the setting of heart failure with preserved ejection fraction (HFpEF), is the most common cause of PH worldwide; however, at present, there is no proven effective therapy available for its treatment. PH-HFpEF is associated with insulin resistance and features of metabolic syndrome. The stable prostacyclin analog, treprostinil, is an effective and widely used Food and Drug Administration-approved drug for the treatment of pulmonary arterial hypertension. While the effect of treprostinil on metabolic syndrome is unknown, a recent study suggests that the prostacyclin analog beraprost can improve glucose intolerance and insulin sensitivity. We sought to evaluate the effectiveness of treprostinil in the treatment of metabolic syndrome-associated PH-HFpEF. Approach and Results: Treprostinil treatment was given to mice with mild metabolic syndrome-associated PH-HFpEF induced by high-fat diet and to SU5416/obese ZSF1 rats, a model created by the treatment of rats with a more profound metabolic syndrome due to double leptin receptor defect (obese ZSF1) with a vascular endothelial growth factor receptor blocker SU5416. In high-fat diet-exposed mice, chronic treatment with treprostinil reduced hyperglycemia and pulmonary hypertension. In SU5416/Obese ZSF1 rats, treprostinil improved hyperglycemia with similar efficacy to that of metformin (a first-line drug for type 2 diabetes mellitus); the glucose-lowering effect of treprostinil was further potentiated by the combined treatment with metformin. Early treatment with treprostinil in SU5416/Obese ZSF1 rats lowered pulmonary pressures, and a late treatment with treprostinil together with metformin improved pulmonary artery acceleration time to ejection time ratio and tricuspid annular plane systolic excursion with AMPK (AMP-activated protein kinase) activation in skeletal muscle and the right ventricle.ConclusionsOur data suggest a potential use of treprostinil as an early treatment for mild metabolic syndrome-associated PH-HFpEF and that combined treatment with treprostinil and metformin may improve hyperglycemia and cardiac function in a more severe disease.

The somatic depressive symptom cluster (including appetite and sleep disturbances) is more strongly associated with insulin resistance (a diabetes risk marker) than other depressive symptom clusters. Utilizing baseline data from 129 primary care patients with depression but no diabetes in the eIMPACT trial (M.sub.age = 59 years, 78% female, 50% Black), we examined associations of somatic depressive symptoms with insulin resistance (HOMA-IR), body mass index (BMI), and high-sensitivity C-reactive protein (hsCRP). We tested BMI and hsCRP as mediators and race as a moderator of these relationships. Hyperphagia was positively associated HOMA-IR ([beta] = 0.19, p = .048) and BMI ([beta] = 0.30, p < .001); poor appetite was negatively associated with HOMA-IR ([beta] = -0.24, p = .02); hypersomnia was positively associated with HOMA-IR ([beta] = 0.28, p = .003), BMI ([beta] = 0.26, p = .003), and hsCRP ([beta] = 0.23, p = .01); and disturbed sleep was positively associated with hsCRP ([beta] = 0.21, p = .04). BMI partially mediated hyperphagia and hypersomnia's associations with HOMA-IR; hsCRP partially mediated the hypersomnia-HOMA-IR association; and race moderated the hyperphagia-HOMA-IR association (positive for White participants but null for Black participants). People with depression experiencing hyperphagia and/or hypersomnia may be a subgroup with greater insulin resistance; BMI and hsCRP are likely pathways in these relationships. This study highlights the importance of considering the direction of somatic depressive symptoms in the context of cardiometabolic disease risk., Author(s): Aubrey L. Shell [sup.1] , Michelle K. Williams [sup.1] , Jay S. Patel [sup.2] , Elizabeth A. Vrany [sup.3] , Robert V. Considine [sup.4] , Anthony J. Acton [sup.4] [...]

Objective: Bariatric surgery reduces sweet‐liking, but mechanisms remain unclear. We examined related brain responses. Methods: A total of 24 nondiabetic bariatric surgery and 21 control participants with normal weight to overweight were recruited for an observational controlled cohort study. They underwent sucrose taste testing outside the scanner followed by stimulation with 0.40M and 0.10M sucrose compared with water during functional magnetic resonance imaging. A total of 21 bariatric participants repeated these procedures after surgery. Results: Perceived sweet intensity was not different among the control, presurgery, or postsurgery groups. Bariatric participants' preferred sweet concentration decreased after surgery (0.52M to 0.29M; p = 0.008). Brain reward system (ventral tegmental area, ventral striatum, and orbitofrontal cortex) region of interest analysis showed that 0.40M sucrose activation (but not 0.10M) decreased after surgery. Sensory region (primary somatosensory and primary taste cortex) 0.40M sucrose activation was unchanged by surgery and did not differ between control and bariatric participants. Primary taste cortex activation to 0.10M sucrose solution was greater in postsurgical bariatric participants compared with control participants. Conclusions: Bariatric surgery reduces the reward system response to sweet taste in women with obesity without affecting activity in sensory regions, which is consistent with reduced drive to consume sweet foods. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatogenic diabetes refers to diabetes mellitus (DM) that develops in the setting of a disease of the exocrine pancreas, including pancreatic ductal adenocarcinoma (PDAC) and chronic pancreatitis (CP). We sought to evaluate whether a blunted nutrient response of pancreatic polypeptide (PP) can differentiate these DM subtypes from type 2 DM (T2DM). Methods: Subjects with new-onset DM (<3 years’ duration) in the setting of PDAC (PDAC-DM, n=28), CP (CP-DM, n=38), or T2DM (n=99) completed a standardized mixed meal tolerance test, then serum PP concentrations were subsequently measured at a central laboratory. Two-way comparisons of PP concentrations between groups were performed using Wilcoxon rank-sum test and analysis of covariance while adjusting for age, sex, and body mass index. Results: The fasting PP concentration was lower in both the PDAC-DM and CP-DM groups than in the T2DM group (P=0.03 and <0.01, respectively). The fold change in PP at 15 minutes following meal stimulation was significantly lower in the PDAC-DM (median, 1.869) and CP-DM (1.813) groups compared with T2DM (3.283; P<0.01 for both comparisons). The area under the curve of PP concentration was significantly lower in both the PDACDM and CP-DM groups than in T2DM regardless of the interval used for calculation and remained significant after adjustments. Conclusions: Fasting PP concentrations and the response to meal stimulation are reduced in new-onset DM associated with PDAC or CP compared with T2DM. These findings support further investigations into the use of PP concentrations to characterize pancreatogenic DM and to understand the pathophysiological role in exocrine pancreatic diseases (NCT03460769). [ABSTRACT FROM AUTHOR]

Endogenous endothelin action is augmented in human obesity and type 2 diabetes and contributes to endothelial dysfunction and impairs insulin-mediated vasodilation in humans. We hypothesized that insulin resistance-associated hyperinsulinemia could preferentially drive endothelin-mediated vasoconstriction. We applied hyperinsulinemic-euglycemic clamps with higher insulin dosing in obese subjects than lean subjects (30 vs. 10 mU x [m.sup.-2] x [min.sup.-1], respectively), with the goal of matching insulin's nitric oxide (NO)-mediated vascular effects. We predicted that, under these circumstances, insulin-stimulated endothelin-I (ET-1) action (assessed with the type A endothelin receptor antagonist BQ-123) would be augmented in proportion to hyperinsulinemia. NO bioactivity was assessed using the nitric oxide synthase inhibitor [N.sup.G]-monomethyl-L-arginine. Insulin-mediated vasodilation and insulin-stimulated NO bioavailability were well matched across groups by this approach. As expected, steady-state insulin levels were approximately threefold higher in obese than lean subjects (109.2 [+ or -] 10.2 pmol/l vs. 518.4 [+ or -] 84.0, P = 0.03). Despite this, the augmentation of insulin-mediated vasodilation by BQ-123 was not different between groups. ET-1 flux across the leg was not augmented by insulin alone but was increased with the addition of BQ-123 to insulin (P = 0.01 BQ-123 effect, P = not significant comparing groups). Endothelin antagonism augmented insulin-stimulated NO bioavailability and NOx flux, but not differently between groups and not proportional to hyperinsulinemia. These findings do not support the hypothesis that insulin resistance-associated hyperinsulinemia preferentially drives endothelin-mediated vasoconstriction. endothelin-1; insulin; obesity

Hepatocyte growth factor (HGF) is a potent mitogenic and angiogenic factor produced in human adipose tissue. In this study, we use 3T3-F442A preadipocytes to study the contribution of HGF to angiogenesis in an in vivo fat pad development model. As observed for human adipocytes, HGF is synthesized and secreted by 3T3-F442A preadipocytes and mature adipocytes. HGF knockdown with small-interfering RNA reduced HGF mRNA expression 82.3 [+ or -] 4.2% and protein secretion 82.9 [+ or -] 1.4% from 3T3-F442A preadipocytes. Silencing of HGF resulted in a 70.5 [+ or -] 19.0% reduction in endothelial progenitor cell migration to 3T3-F442A-conditioned medium in vitro. 3T3-F442A preadipocytes injected under the skin of mice form a fat pad containing mature, lipid-filled adipocytes and a functional vasculature. At 72 h postinjection, expression of the endothelial cell genes TIE-1 and platelet endothelial cell adhesion molecule (PECAM)-1 was decreased 94.4 [+ or -] 2.2 and 91.5 [+ or -] 2.5%, respectively, in 3T3-F442A fat pads with HGF silencing. Knockdown of HGF had no effect on differentiation of 3T3-F442A preadipocytes to mature adipocytes in vitro or in vivo. In developing fat pads under the skin of HGF overexpressing transgenic mice, TIE-1 and PECAM-1 mRNA was increased 16.5- and 21.4-fold, respectively, at 72 h postinjection. The increase in gene expression correlated with immunohistochemical evidence of endothelial cell migration in the developing fat pad. These data suggest that HGF has a central role in regulating angiogenesis in adipose tissue. obesity; neovascularization; 3T3-F442A; tie-1; platelet endothelial cell adhesion molecule-1

Serum HGF is elevated in obese individuals. This study examined the contribution of excess adipose tissue to increased circulating HGF levels in obesity. Serum HGF was measured by ELISA before and after weight loss due to bariatric surgery or a 24-h fast. At 6.1 [+ or -] 0.1 mo following surgery, BMI (50.6 [+ or -] 1.6 vs. 35.1 [+ or -] 1.3 kg/[m.sup.2]; P < 0.0001) and serum HGF were significantly decreased (1,164 [+ or -] 116 vs. 529 [+ or -] 39 pg/ml, P < 0.001). A 24-h fast did not change serum HGF, but serum leptin was significantly reduced (67.7 [+ or -] 7.1 vs. 50.3 2 8.3 ng/ml, P = 0.02). HGF secretion in vitro from adipocytes of obese (BMI 40.3 [+ or -] 2.8 kg/[m.sup.2]) subjects was significantly greater (80.9 [+ or -] 10.4 vs. 21.5 [+ or -] 4.0 pg/[10.sup.5] cells, P = 0.008) than release from adipocytes of lean (BMI 23.3 [+ or -] 1.4 kg/[m.sup.2]) subjects. HGF mRNA levels determined by real-time RT-PCR were not different in adipocytes from lean (BMI 24.0 [+ or -] 0.8 kg/[m.sup.2]) and obese (45.7 [+ or -] 3.0 kg/[m.sup.2]) subjects, but serum HGF was significantly elevated in the obese individuals studied (787 [+ or -] 61 vs. 489 [+ or -] 49 pg/ml, P = 0.001). TNF-[alpha] (24 h treatment) significantly increased HGF release from subcutaneous adipocytes 23.6 [+ or -] 8.3% over control (P = 0.02). These data suggest that elevated serum HGF in obesity is in part attributable to excess adipose tissue and that this effect can be reversed by reducing adipose tissue mass through weight loss. Increased HGF secretion from adipocytes of obese subjects may be due to posttranscriptional events possibly related to adipocyte size and stimulation by elevated TNF-[alpha] in the adipose tissue of obese individuals. adipocytes; obesity; tumor necrosis factor-s; adiponectin; leptin; weight loss; hepatocyte growth factor

It is well established that endothelial dysfunction and insulin resistance go hand in hand. However, it is unclear whether endothelial dysfunction per se is sufficient to impair insulin-mediated glucose uptake. We have previously reported that 4 wk of administration of the human immunodeficiency virus (HIV)-1 protease inhibitor indinavir to HIV-negative subjects induces endothelial dysfunction. Hence, we hypothesized that indinavir-induced endothelial dysfunction was associated with impaired insulin-mediated glucose disposal. We measured insulin-mediated glucose disposal at the level of the whole body, skeletal muscle, and vasculature by performing hyperinsulinemic euglycemic clamp, and vascular function studies, in a separate group of HIV-negative healthy nonobese subjects (n = 13) before and after 4 wk of daily oral indinavir. Four weeks of indinavir resulted in a 113 [+ or -] 29% (P < 0.01) reduction of endothelium-dependent vasodilation, consistent with our earlier findings. In addition, there was a significant impairment of insulin-mediated vasodilation (101 [+ or -] 14% before indinavir vs. 35 [+ or -] 15% after indinavir; P < 0.05). However, there was no significant change in insulin-mediated glucose disposal at the level of the whole body (8.9 [+ or -] 0.5 before indinavir vs. 8.5 [+ or -] 0.6 mg x [kg.sup.1] x [min.sup.-1] after indinavir; P = 0.4), or skeletal muscle. Furthermore, in a separate group of four HIV-negative healthy nonobese subjects, we found that 4 wk of indinavir has no sustained effect on insulin-stimulated glucose uptake in adipose tissue. Thus our findings indicate that I) endothelial dysfunction alone is insufficient to impair insulin-mediated glucose disposal, and 2) indinavir-induced endothelial dysfunction is likely due to a direct effect of the drug on the endothelium and is not coupled to the induction of insulin resistance. endothelium; protease inhibitor; vascular function; glucose disposal