Diabetic background retinopathy is associated with impaired coronary vasoreactivity in people with Type 1 diabetes

Abstract

Aims/hypothesis. We examined whether diabetic background retinopathy is associated with reduced coronary vasoreactivity in people with Type 1 diabetes. Methods. A total of 21 men with Type 1 diabetes were investigated, including 9 men with background retinopathy and 12 men without retinopathy. In addition, 12 non-diabetic, age-matched subjects were studied. All subjects were non-smokers, otherwise healthy and had no other diabetic complications. Resting myocardial blood flow and hyperaemic dipyridamole-stimulated flow (dipyridamole, 0.56 mg/kg during a 4-min period), a measure of coronary vasoreactivity, were measured during euglycaemic hyperinsulinaemic clamp (1 mU·kg −1 ·min −1 ) using positron emission tomography and oxygen-15-labelled water. Results. Resting myocardial blood flow (0.82±0.13 vs 0.96±0.23 vs 0.88±0.25 ml·g −1 ·min −1 , with vs without retinopathy vs non-diabetic subjects) and coronary vascular resistance (111.2±23.4 vs 95.5±15.8 vs 101.9±31.5 mmHg·min·g·ml −1 respectively) were not significantly different between the groups. Dipyridamole infusion induced an increase in blood flow and a decrease in coronary vascular resistance in all study subjects (p<0.001). However, dipyridamole-stimulated flow and coronary vascular resistance were blunted in diabetic patients with retinopathy (2.9±0.9 ml·g −1 · min −1 and 34.1±11.3 mmHg·min·g·ml −1 ) when compared to diabetic patients without retinopathy (4.0±1.3 ml·g −1 ·min −1 , p=0.04 and 24.6±7.5 mmHg·min·g·ml −1 , p=0.03) or non-diabetic subjects (4.5±1.4 ml·g −1 ·min −1 , p=0.008 and 22.2±8.7 mmHg·min·g·ml −1 , p=0.01). Myocardial flow reserve was impaired in diabetic patients with retinopathy (3.6±1.0) when compared to non-diabetic subjects (5.3±1.9, p=0.02) but not significantly reduced when compared to diabetic patients without retinopathy (4.2±1.4, p=0.2). Conclusions/interpretation. Diabetic background retinopathy appears to be associated with impaired coronary vasoreactivity in young people with Type 1 diabetes.Keywords Myocardial blood flow · Type 1 diabetes · Retinopathy · Dipyridamole · Positron emission tomography

High-sensitivity C-reactive protein and impaired coronary vasoreactivity in young men with uncomplicated type 1 diabetes

“…However, studies with young type 1 diabetic subjects without complications have mainly shown normal coronary vasoreactivity [10,12,13,14]. The present study is the first study to examine the effect of hsCRP on coronary vasoreactivity in subjects with type 1 diabetes.…”

“…In previous studies coronary vasoreactivity has been found to be decreased in diabetic patients with complications or other risk factors for coronary artery disease [7,8,9,11,12,13]. However, studies with young type 1 diabetic subjects without complications have mainly shown normal coronary vasoreactivity [10,12,13,14].…”

“…However, most of these previous studies included patients with both type 1 and type 2 diabetes and/or included diabetic patients with other potentially confounding factors such as diabetic complications, smoking, hypertension, obesity and lipid abnormalities, which are known to impair coronary vasoreactivity. The question of whether coronary vasoreactivity is impaired in subjects with uncomplicated type 1 diabetes who are otherwise healthy is still controversial [10,12,13,14]. Elevated hsCRP concentrations are associated with markers of endothelial dysfunction [15].…”

Retinal Microvascular Signs Are Associated with Chronic Kidney Disease in Persons with and without Diabetes

“…Our findings are consistent with those from the Atherosclerosis Risk in Communities (ARIC) Study [7] and Cardiovascular Health Study [8], in which retinopathy lesions were associated with renal dysfunction. Retinopathy lesions are associated with abnormalities in the coronary circulation [23,24,25,26] and may thus be a marker of generalized microvascular disease from vascular endothelial dysfunction [27] in the retina, kidney and other microvascular beds.…”

Coronary Circulatory Function Abnormalities in Insulin Resistance

“…Perfusion defects were noted in 16% of patients, and adenosine stress-induced ischemic electrocardiographic abnormalities or left ventricular dilation or dysfunction occurred in 6% of the patients with normal myocardial perfusion. Microvascular structural alterations affect coronary circulatory function more uniformly, judging from the homogenously reduced hyperemic flow patterns observed in patients with T2DM and diabetic retinopathy or coronary microangiopathy (19,20). Compared with controls, hyperemic myocardial flow was reduced by 28% in patients with T2DM and macrovascular coronary disease, but was reduced by 57% in patients with T2DM and coronary microangiopathy (20).…”