scholarly journals Retinal Vessel Diameter Changes in Relation to Dark Adaptation and Acute Hyperglycemia

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Per Kappelgaard ◽  
Stig K. Holfort ◽  
Oliver N. Klefter ◽  
Michael Larsen
Keyword(s):  
Type 2 Diabetes ◽  
Diabetic Retinopathy ◽  
Dark Adaptation ◽  
Retinal Vessel ◽  
Vessel Diameter ◽  
Postprandial Hyperglycemia ◽  
Oral Glucose ◽  
Retinal Artery ◽  
Retinal Vessel Diameters

The purpose of this experimental clinical study was to assess the effects of dark adaptation and acute changes in glycemia on retinal vessel diameters in men. The study included 14 patients (mean age 63 years, range 48–74 years) with type 2 diabetes mellitus and minimal or no diabetic retinopathy. Retinal vessel diameters were assessed using infrared photography before and after dark adaptation, first while fasting and then at peak hyperglycemia during an oral glucose tolerance test (OGTT). Dark adaptation was accompanied by retinal vasodilatation, both during fasting (mean glycemia 7.6 ± 1.7 mM) and postprandial hyperglycemia (15.7 ± 4.2 mM). When fasting, the increase in vein diameter during dark adaptation was 2.0% after 20 min (P=0.018) and 2.9% after 40 min (P=0.010). When subjects were hyperglycemic, the increase during dark adaptation was 2.8% for retinal vein diameters (P=0.027) and 2.0% for retinal artery diameters after 20 min (P=0.002) and 1.7% for retinal artery diameters after 40 min (P=0.022). For identical conditions of light/dark adaptation, retinal vessels were dilated when subjects were fasting compared to postprandial hyperglycemia. Thus, darkness and fasting were both associated with retinal vasodilation in this short-term experiment in patients with type 2 diabetes. Future studies should determine whether both the stimuli of vasodilation lead to retinal hyperperfusion, which would support that they may be involved in the aggravation of diabetic retinopathy.

scholarly journals Retinal venular tortuosity and fractal dimension predict incident retinopathy in adults with type 2 diabetes: the Edinburgh Type 2 Diabetes Study

Diabetologia ◽  
2021 ◽  
Author(s):  
Rachel B. Forster ◽  
◽  
Emmanuel Sandoval Garcia ◽  
Anniek J. Sluiman ◽  
Sheila M. Grecian ◽  
...  
Keyword(s):  
Risk Factors ◽  
Type 2 Diabetes ◽  
Diabetic Retinopathy ◽  
Fractal Dimension ◽  
Statistical Significance ◽  
Fractal Dimensions ◽  
Retinal Vessel ◽  
Related Factors ◽  
Discriminative Ability

Abstract Aims/hypothesis Our aim was to determine whether a range of prespecified retinal vessel traits were associated with incident diabetic retinopathy in adults with type 2 diabetes. Methods In the prospective observational cohort Edinburgh Type 2 Diabetes Study of 1066 adults with type 2 diabetes, aged 60–75 years at recruitment, 718 were free from diabetic retinopathy at baseline. Baseline retinal traits including vessel widths, tortuosity (curvature) and fractal dimensions (network complexity), were quantified using fundus camera images and semiautomated software, and analysed using logistic regression for their association with incident diabetic retinopathy over 10 years. Results The incidence of diabetic retinopathy was 11.4% (n = 82) over 10 years. After adjustment for a range of vascular and diabetes-related risk factors, both increased venular tortuosity (OR 1.51; 95% CI 1.15, 1.98; p = 0.003) and decreased fractal dimension (OR 0.75; 95% CI 0.58, 0.96; p = 0.025) were associated with incident retinopathy. There was no evidence of an association with arterial tortuosity, and associations between measurements of vessel widths and retinopathy lost statistical significance after adjustment for diabetes-related factors and vascular disease. Adding venular tortuosity to a model including established risk factors for diabetic retinopathy (HbA1c, BP and kidney function) improved the discriminative ability (C statistic increased from 0.624 to 0.640, p = 0.013), but no such benefit was found with fractal dimension. Conclusions/interpretation Increased retinal venular tortuosity and decreased fractal dimension are associated with incident diabetic retinopathy, independent of classical risk factors. There is some evidence that venular tortuosity may be a useful biomarker to improve the predictive ability of models based on established retinopathy risk factors, and its inclusion in further risk prediction modelling is warranted. Graphical abstract

Mechanism of action of exenatide to reduce postprandial hyperglycemia in type 2 diabetes

2008 ◽  
Vol 294 (5) ◽  
pp. E846-E852 ◽  
Author(s):  
Antonio Cervera ◽  
Estela Wajcberg ◽  
Apiradee Sriwijitkamol ◽  
Marianella Fernandez ◽  
Pengou Zuo ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Gastric Emptying ◽  
Delayed Gastric Emptying ◽  
Postprandial Hyperglycemia ◽  
Oral Glucose ◽  
Plasma Glucagon ◽  
Tracer Technique ◽  
Mixed Meal ◽  
Glucagon Suppression

We examined the contributions of insulin secretion, glucagon suppression, splanchnic and peripheral glucose metabolism, and delayed gastric emptying to the attenuation of postprandial hyperglycemia during intravenous exenatide administration. Twelve subjects with type 2 diabetes (3 F/9 M, 44 ± 2 yr, BMI 34 ± 4 kg/m2, Hb A1c 7.5 ± 1.5%) participated in three meal-tolerance tests performed with double tracer technique (iv [3-3H]glucose and oral [1-14C]glucose): 1) iv saline (CON), 2) iv exenatide (EXE), and 3) iv exenatide plus glucagon (E+G). Acetaminophen was given with the mixed meal (75 g glucose, 25 g fat, 20 g protein) to monitor gastric emptying. Plasma glucose, insulin, glucagon, acetaminophen concentrations and glucose specific activities were measured for 6 h post meal. Post-meal hyperglycemia was markedly reduced ( P < 0.01) in EXE (138 ± 16 mg/dl) and in E+G (165 ± 12) compared with CON (206 ± 15). Baseline plasma glucagon (∼90 pg/ml) decreased by ∼20% to 73 ± 4 pg/ml in EXE ( P < 0.01) and was not different from CON in E+G (81 ± 2). EGP was suppressed by exenatide [231 ± 9 to 108 ± 8 mg/min (54%) vs. 254 ± 29 to189 ± 27 mg/min (26%, P < 0.001, EXE vs. CON] and partially reversed by glucagon replacement [247 ± 15 to 173 ± 18 mg/min (31%)]. Oral glucose appearance was 39 ± 4 g in CON vs. 23 ± 6 g in EXE ( P < 0.001) and 15 ± 5 g in E+G, ( P < 0.01 vs. CON). The glucose retained within the splanchnic bed increased from ∼36g in CON to ∼52g in EXE and to ∼60g in E+G ( P < 0.001 vs. CON). Acetaminophen(AUC) was reduced by ∼80% in EXE vs. CON ( P < 0.01). We conclude that exenatide infusion attenuates postprandial hyperglycemia by decreasing EGP (by ∼50%) and by slowing gastric emptying.

Angiopoietin 1 in patients with type 2 diabetes mellitus and diabetic retinopathy

2015 ◽  
Author(s):  
Sattar El-Deeb Abd El ◽  
Mohamed Halawa ◽  
Ahmed Saad ◽  
Inas Sabry ◽  
Maram Mahdy ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Diabetic Retinopathy ◽  
Angiopoietin 1

592-P: Diabetic Retinopathy Grade as Predictor of Outcomes in Patients with Type 2 Diabetes and Lower Extremity Amputations—Multicentric Longitudinal Seven-Year Study

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 592-P
Author(s):  
KIRAN SHAH ◽  
SUNDARAM NATARAJAN ◽  
VISHWANATH PARSEWAR ◽  
VYANKATESH K. SHIVANE
Keyword(s):  
Type 2 Diabetes ◽  
Diabetic Retinopathy ◽  
Lower Extremity

Relationship between diabetic retinopathy and cerebral perfusion in type 2 diabetes mellitus

2018 ◽  
Vol 71 (1) ◽  
pp. 49-53
Author(s):  
N. Zherdiova ◽  
◽  
N. Medvedovska ◽  
B Mankovsky ◽  
◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Diabetic Retinopathy ◽  
Cerebral Perfusion
Sign in / Sign up

Export Citation Format

Share Document