scholarly journals Effects of Glucose Control and Variability on Endothelial Function and Repair in Adolescents with Type 1 Diabetes

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Robert P. Hoffman ◽  
Amanda S. Dye ◽  
Hong Huang ◽  
John A. Bauer
Keyword(s):  
Type 1 Diabetes ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Hemoglobin A1c ◽  
Glucose Monitoring ◽  
Area Under The Curve ◽  
Vascular Occlusion ◽  
Venous Occlusion ◽  
Mean Glucose

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.

scholarly journals The Relationships Between Time in Range, Hyperglycemia Metrics, and HbA1c

2019 ◽  
Vol 13 (4) ◽  
pp. 614-626 ◽  
Author(s):  
Roy W. Beck ◽  
Richard M. Bergenstal ◽  
Peiyao Cheng ◽  
Craig Kollman ◽  
Anders L. Carlson ◽  
...  
Keyword(s):  
Hemoglobin A1c ◽  
Glucose Monitoring ◽  
Area Under The Curve ◽  
High Blood Glucose ◽  
Wide Range ◽  
Time In Range ◽  
Highly Correlated ◽  
Mean Glucose ◽  
Considerable Spread

Background: As the use of continuous glucose monitoring (CGM) increases, there is a need to better understand key metrics of time in range 70-180 mg/dL (TIR70-180) and hyperglycemia and how they relate to hemoglobin A1c (A1C). Methods: Analyses were conducted utilizing datasets from four randomized trials encompassing 545 adults with type 1 diabetes (T1D) who had central-laboratory measurements of A1C. CGM metrics were calculated and compared with each other and A1C cross-sectionally and longitudinally. Results: Correlations among CGM metrics (TIR70-180, time >180 mg/dL, time >250 mg/dL, mean glucose, area under the curve above 180 mg/dL, high blood glucose index, and time in range 70-140 mg/dL) were typically 0.90 or greater. Correlations of each metric with A1C were lower (absolute values 0.66-0.71 at baseline and 0.73-0.78 at month 6). For a given TIR70-180 percentage, there was a wide range of possible A1C levels that could be associated with that TIR70-180 level. On average, a TIR70-180 of 70% and 50% corresponded with an A1C of approximately 7% and 8%, respectively. There also was considerable spread of change in A1C for a given change in TIR70-180, and vice versa. An increase in TIR70-180 of 10% (2.4 hours per day) corresponded to a decrease in A1C of 0.6%, on average. Conclusions: In T1D, CGM measures reflecting hyperglycemia (including TIR and mean glucose) are highly correlated with each other but only moderately correlated with A1C. For a given TIR or change in TIR there is a wide range of possible corresponding A1C values.

scholarly journals Eight-Point Glucose Testing Versus the Continuous Glucose Monitoring System in Evaluation of Glycemic Control in Type 1 Diabetes

2005 ◽  
Vol 90 (6) ◽  
pp. 3387-3391 ◽  
Keyword(s):  
Type 1 Diabetes ◽  
Monitoring System ◽  
Continuous Glucose Monitoring ◽  
Hemoglobin A1c ◽  
Glucose Monitoring ◽  
Continuous Glucose Monitoring System ◽  
Diabetes Research ◽  
Glucose Profiles ◽  
Mean Glucose

Context: Advantages/disadvantages of continuous vs. discrete glucose monitoring are not well documented. Objective: Compare glucose profiles from home meters vs. continuous sensors. Design: Randomized clinical trial conducted by the Diabetes Research in Children Network (DirecNet) to assess the utility of the GlucoWatch G2 Biographer. Setting: Home glucose measurements. Patients: Two hundred children (age, 7 to < 18 yr) with type 1 diabetes. Intervention: At baseline, subjects were asked to wear the continuous glucose monitoring system (CGMS) sensor and perform meter tests at eight prespecified times of the day (eight-point testing) each for 3 d (2 d using both, 1 d eight-point testing only, 1 d CGMS only). Hemoglobin A1c was measured in a central laboratory. Main Outcome Measure: Six-month hemoglobin A1c. This analysis looked at baseline glucose profiles/hemoglobin A1c. Results: Only 10% of subjects completed full eight-point testing for 3 d, but median CGMS use was 70 h. Mean glucose was lower when measured by the CGMS compared with eight-point testing (183 ± 37 vs. 188 ± 41 mg/dl; 10.2 ± 2.1 vs.10.4 ± 2.3 mmol/liter; P = 0.009), especially overnight (2400–0400 h; 174 vs. 199 mg/dl; 9.7 vs. 11.1 mmol/liter; P < 0.001). Associations of hemoglobin A1c with mean glucose were similar for eight-point testing [slope 23 mg/dl per 1% (1.3 mmol/liter); correlation 0.40; P < 0.001] and CGMS [slope 19 mg/dl per 1% (1.1 mmol/liter); correlation 0.39; P < 0.001]. Postprandial excursions were lower for eight-point testing vs. CGMS, especially after dinner (mean excursion −17 vs. 63 mg/dl; −1.0 vs. 3.5 mmol/liter; P < 0.001). Conclusions: Both methods gave similar mean glucose profiles and associations with hemoglobin A1c. Advantages of the CGMS were higher density of data and better detection of postprandial peaks. However, the CGMS may overestimate the frequency of low glucose levels, especially overnight.

Frequency of flash glucose monitoring readings, hemoglobin A1c and time in range: a real life study in adults with type 1 diabetes

2020 ◽  
Vol 57 (11) ◽  
pp. 1395-1397 ◽  
Author(s):  
Andrea Laurenzi ◽  
Amelia Caretto ◽  
Mariluce Barrasso ◽  
Andrea Mario Bolla ◽  
Nicoletta Dozio ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Hemoglobin A1c ◽  
Real Life ◽  
Glucose Monitoring ◽  
Flash Glucose Monitoring ◽  
Life Study ◽  
Time In Range ◽  
Real Life Study

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

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Amanda S. Dye ◽  
Hong Huang ◽  
John A. Bauer ◽  
Robert P. Hoffman
Keyword(s):  
Blood Flow ◽  
Type 1 Diabetes ◽  
Endothelial Function ◽  
Vascular Function ◽  
Microvascular Complications ◽  
Muscle Blood Flow ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Before And After

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/m2/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.

Evaluation of Hemoglobin A1c before and after initiation of continuous glucose monitoring in children with type 1 diabetes mellitus

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shilpa Gurnurkar ◽  
Lindsey Owens ◽  
Sweta Chalise ◽  
Neha Vyas
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Continuous Glucose Monitoring ◽  
Hba1c Level ◽  
Hemoglobin A1c ◽  
Glucose Monitoring ◽  
Retrospective Chart Review ◽  
Dependent Samples

Abstract Objectives The development of continuous glucose monitoring (CGM) systems has allowed for identification of blood sugar variations and trends in real-time that is not feasible with conventional self-monitoring of blood glucose. However, there is inconsistent data to show that the use of CGM leads to better glycemic control as measured by Hemoglobin A1c (HbA1c) in pediatric patients with type 1 diabetes mellitus. Our study aimed to compare the average HbA1c level in the 1–2 years prior to starting a CGM to the average HbA1c level in the 1–2 years immediately following CGM initiation in a sample of 1–20 year olds with type 1 diabetes mellitus. Methods Participants were 90 youth (ages 1–20) followed for type 1 diabetes care at our institution who used a CGM for at least a 6 month time period. We performed a retrospective chart review to obtain up to four HbA1c values pre and post-CGM initiation each. We evaluated pre- and post-CGM initiation changes in mean HbA1c via dependent samples t-tests using IBM SPSS 24.0. Results The mean HbA1c was 8.7% pre-CGM and decreased to 8.27% 9–12 months after CGM initiation in the overall sample. A statistically significant decrease in HbA1c was seen in patients who used multiple daily injections (p=0.02), those with a pre-CGM HbA1c greater than 9% (p=0.01), and those with a diabetes duration of 5–10 years (p=0.02). Conclusion CGM use was associated with a decrease in HbA1c over time which was statistically significant in some subgroups.

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