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The infusion of glucosamine causes insulin resistance, presumably by entering the hexosamine biosynthetic pathway; it has been proposed that this pathway plays a role in hyperglycemia-induced insulin resistance. This study was undertaken to determine if glucosamine infusion could influence exercise-stimulated glucose uptake. Male SD rats were infused with glucosamine at 0.1 mg x kg(-1) x min(-1) (low-GlcN group), 6.5 mg x kg(-1) x min(-1) (high-GlcN group), or saline (control group) for 6.5 h and exercised on a treadmill for 30 min (17 m/min) at the end of the infusion period. Glucosamine infusion caused a modest increase in basal glycemia in both experimental groups, with no change in tracer-determined basal glucose turnover. During exercise, glucose turnover increased approximately 2.2-fold from 46 +/- 2 to 101 +/- 5 pmol x kg(-1) x min(-1) in the control group. Glucose turnover increased to a lesser extent in the glucosamine groups and was limited to 88% of control in the low-GlcN group (47 +/- 2 to 90 +/- 3 pmol x kg(-1) x min(-1); P < 0.01) and 72% of control in the high-GlcN group (43 +/- 1 to 73 +/- 3 pmol kg(-1) 1 min(-1); P < 0.01). Similarly, the metabolic clearance rate (MCR) in the control group increased 72% from 6.1 +/- 0.2 to 10.5 +/- 0.7 ml kg(-1) x min(-1) in response to exercise. However, the increase in MCR was only 83% of control in the low-GlcN group (5.2 +/- 0.5 to 8.7 +/- 0.5 ml x kg(-1) x min(-1); P < 0.01) and 59% of control in the high-GlcN group (4.5 +/- 0.2 to 6.2 +/- 0.3 ml x kg(-1) x min(-1); P < 0.01). Neither glucosamine infusion nor exercise significantly affected plasma insulin or free fatty acid (FFA) concentrations. In conclusion, the infusion of glucosamine, which is known to cause insulin resistance, also impaired exercise-induced glucose uptake. This inhibition was independent of hyperglycemia and FFA levels. [ABSTRACT FROM AUTHOR]

Background: Currently, pulmonary hypertension-targeted therapy has been shown to improve the survival of patients with pulmonary artery hypertension (PAH). However, the importance of early diagnosis has not been investigated. Therefore, this study aimed to investigate whether a delayed diagnosis of PAH is associated with its prognosis., Methods and Results: A total of 66 consecutive untreated patients were diagnosed with PAH from January 2008 to December 2021 at the Kagoshima University Hospital. The time from symptom onset to diagnosis correlated with brain natriuretic peptide levels (p < 0.001), right ventricle (RV) Tei index (p < 0.001), and the tricuspid annular plane systolic excursion/systolic pulmonary artery pressure ratio (p = 0.003). These findings suggest that in patients with PAH, RV function declines with increasing time from symptom onset to diagnosis. Furthermore, older patients with PAH appeared to have a longer time from symptom onset to diagnosis. Next, patients were divided into delayed diagnosis (>3 months) and early diagnosis (≤3 months) groups based on the time from symptom onset to diagnosis. Patients were categorized into three groups according to the European Society of Cardiology (or the European Respiratory Society) risk stratification guidelines. Patients diagnosed with PAH within 3 months of symptom onset were significantly in the low- or intermediate-risk groups (p < 0.001). A Kaplan-Meier analysis revealed that the cumulative event-free rate was significantly lower (p < 0.01) in the delayed diagnosis group than in the early diagnosis group. A delayed diagnosis was significantly associated with a worse outcome than an early diagnosis, after adjusting for different sets of confounding factors., Conclusions: A delayed PAH diagnosis is associated with a poor prognosis. Early diagnosis of PAH may lead to a low-risk treatment. Furthermore, older patients need more careful screening for PAH., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)