Hyperglycemia Increases Muscle Blood Flow and Alters Endothelial Function in Adolescents with Type 1 Diabetes

Department of Pediatrics, West Virginia University, Charleston, WV 25302, USA.
Experimental Diabetes Research (Impact Factor: 3.54). 06/2012; 2012:170380. DOI: 10.1155/2012/170380
Source: PubMed

ABSTRACT Alterations of blood flow and endothelial function precede development of complications in type 1 diabetes. The effects of hyperglycemia on vascular function in early type 1 diabetes are poorly understood. To investigate the effect of hyperglycemia on forearm vascular resistance (FVR) and endothelial function in adolescents with type 1 diabetes, FVR was measured before and after 5 minutes of upper arm arterial occlusion using venous occlusion plethysmography in (1) fasted state, (2) euglycemic state (~90 mg/dL; using 40 mU/m(2)/min insulin infusion), and (3) hyperglycemic state (~200 mg/dL) in 11 adolescents with type 1 diabetes. Endothelial function was assessed by the change in FVR following occlusion. Seven subjects returned for a repeat study with hyperglycemia replaced by euglycemia. Preocclusion FVR decreased from euglycemia to hyperglycemia (P = 0.003). Postocclusion fall in FVR during hyperglycemia was less than during euglycemia (P = 0.002). These findings were not reproduced when hyperglycemia was replaced with a second euglycemia. These results demonstrate that acute hyperglycemia causes vasodilation and alters endothelial function in adolescents with type 1 diabetes. In addition they have implications for future studies of endothelial function in type 1 diabetes and provide insight into the etiology of macrovascular and microvascular complications of type 1 diabetes.

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    ABSTRACT: Studies on the alterations of liver and kidney function parameters in patients with diabetic ketoacidosis (DKA) and diabetic ketosis (DK) were limited. Participants with DKA, DK, non-DK, and healthy controls were enrolled in the current study. Parameters of liver and kidney function were measured and evaluated. The patients with DKA had higher levels of plasma glucose, hemoglobin A1c (HbA1c), uric acid, and creatinine but lower levels of transferases and protein compared with the other three groups (P < 0.05 for all). The patients with DK had higher levels of plasma glucose and HbA1c but lower levels of glutamyl transpeptidase and protein compared with the non-DK and control groups (P < 0.05). Prealbumin levels were significantly reduced in the severe DKA patients compared with the mild/moderate DKA patients. Serum prealbumin levels were correlated with albumin levels (r = 0.401, P = 0.010), HCO3 (r = 0.350, P = 0.027), and arterial pH (r = 0.597, P < 0.001) in the DKA patients. A diagnostic analysis showed that lower prealbumin levels significantly reflected the presence of hyperglycemic emergencies (P < 0.001). Liver and kidney function parameters deteriorated, especially in DKA. Prealbumin levels can be of value in detecting the presence of hyperglycemic crisis. This clinical trial is registered with ChiCTR-OCH-12003077.
    Journal of Diabetes Research 01/2013; 2013:967097. DOI:10.1155/2013/967097 · 3.54 Impact Factor
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    ABSTRACT: AimLittle is known about endothelial function in adolescents with type 1 diabetes and we evaluated endothelial dysfunction, using reactive hyperaemia peripheral arterial tonometry (RH-PAT).Methods This prospective, observational, one-year study, focused on 73 adolescents with type 1 diabetes, using multiple daily injections or continuous subcutaneous insulin infusion. The subjects were assessed using RH-PAT, body mass index, blood pressure, fasting lipid profile, glycated haemoglobin, insulin requirements and hours of physical exercise per week.ResultsEndothelial dysfunction was observed in 56 patients (76.7%), with lower mean RH-PAT scores (1.26±0.22 vs. 2.24±0.48, p<0.0001) and higher glycated haemoglobin values at baseline (8.27±1.24% vs. 7.37±0.54%, p=0.006) and as a mean of the whole period since diagnosis (8.25±1.22% vs. 7.72±0.82%, p=0.034). A higher percentage of patients with endothelial dysfunction showed abnormal cardiac autonomic tests (p=0.02) and were more sedentary, exercising less than four times a week, than patients with normal endothelial function. After follow-up in 64/73 patients, we observed endothelial dysfunction in 81.8% of patients, albeit a modest improvement in glycated haemoglobin.Conclusions Adolescents with type 1 diabetes displayed evidence of endothelial dysfunction. Good metabolic control (glycated haemoglobin ≤7.5%, 58 mmol/mol) and regular physical activity of at least four hours a week might be protective.This article is protected by copyright. All rights reserved.
    Acta Paediatrica 11/2014; 104(2). DOI:10.1111/apa.12877 · 1.97 Impact Factor
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    ABSTRACT: Background. Endothelial dysfunction and increased inflammation are precursors of cardiovascular disease in type 1 diabetes (T1D) and occur even in adolescents with T1D. The goal of this study was to determine the relationship of endothelial dysfunction to various measures of glycemia. Research Design and Methods. Forearm blood flow (FBF, venous occlusion plethysmography) was measured before and after 5 min of upper arm vascular occlusion in 17 adolescents with uncomplicated type 1 diabetes. Endothelial function was assessed as postocclusion FBF and forearm vascular resistance (FVR, mean arterial pressure/FBF). Fasting glucose, 72 hour mean glucose and standard deviation from continuous glucose monitoring, hemoglobin A1c, and hemoglobin A1c by duration area under the curve were used to assess immediate, short-term, and intermediate- and long-term glycemia. Results. Postocclusion FBF (r = -0.53, P = 0.030) negatively correlated and postocclusion FVR positively correlated (r = 0.52, P = 0.031) with hemoglobin A1c levels. FVR was positively associated with log 3 day mean glucose (r = 0.55, P = 0.027). Postocclusion FBF (2.8 ± 1.1 versus 3.4 ± 0.5 mL/dL/min, mean ± SE, P = 0.084) tended to be lower and FVR (31.4 ± 10.4 versus 23.9 ± 4.4 mmHg dL min/mL, P = 0.015) was significantly higher in subjects with hemoglobin A1c above the median (8.3%) compared to those with lower hemoglobin A1c levels. Conclusions. These results demonstrate that poor intermediate-term glycemic control is associated with impaired endothelial function.
    01/2013; 2013:876547. DOI:10.1155/2013/876547


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