Coronary Flow Reserve Is Reduced in Young Men With IDDM

Abstract

Disturbances of coronary circulation have been reported in diabetic patients with microvascular complications but without obstructive coronary atherosclerosis. The aim of the present study was to investigate coronary flow reserve in young adult patients with IDDM but without microalbuminuria and diabetic autonomic neuropathy. Coronary flow reserve was determined in 12 nonsmoking male patients with IDDM (age 30.0 +/- 6.6 years) and 12 healthy matched volunteers. Groups were similar with respect to blood pressure and serum lipid concentrations, and no subject had a positive family history of coronary heart disease. The patients with IDDM had normal exercise echocardiography and autonomic nervous function tests. Five patients had minimal background retinopathy, and none had microalbuminuria. Positron emission tomography and [15O]H2O were used to measure myocardial blood flow at rest and after dipyridamole administration. The studies were performed during euglycemic hyperinsulinemia (serum insulin approximately 70 mU/l). The baseline myocardial blood flow was similar in patients with IDDM and in control subjects (0.84 +/- 0.18 vs. 0.88 +/- 0.25 ml x g(-1) x min(-1), NS). The myocardial blood flow during hyperemia was 29% lower in patients with IDDM (3.17 +/- 1.57) compared with the control subjects (4.45 +/- 1.37 ml x g(-1) x min(-1), P < 0.05). Consequently, coronary flow reserve (the ratio of flow during hyperemia and at rest) was lower in diabetic patients than in control subjects (3.76 +/- 1.69 vs. 5.31 +/- 1.86, P < 0.05) and the total coronary resistance during hyperemia was higher in diabetic patients (53.7 +/- 31.5) compared with the control subjects (31.4 +/- 11.6 mmHg x min x g x ml(-1), P < 0.05). The coronary flow reserve was similar in diabetic patients with and without mild background retinopathy. No association was found between the coronary flow reserve and serum lipid or HbA1c values in either group. Coronary flow reserve is impaired in young adult males with IDDM and no or minimal microvascular complications and without any evidence of coronary heart disease. This abnormality cannot be explained by standard coronary heart disease risk factors. The results imply early impairment of coronary vascular reactivity in IDDM patients, which may represent an early precursor of future coronary heart disease or may contribute to the pathogenesis of diabetic cardiomyopathy.

Quantitative relationship between coronary vasodilator reserve assessed by 82Rb PET imaging and coronary artery stenosis severity

“…Our results also agree with an earlier report by Goldstein et al, who studied 41 patients with CAD using either Rubidium-82 or 13 N-ammonia and demonstrated a strong curvilinear relationship between relative perfusion reserve (defined as the ratio of hyperaemic to resting perfusion in the stenosis-related region divided by the ratio in a remote region) and percentage of vessel diameter or area stenosis (16). Extending further these observations in the clinical setting, we found that despite the fact that most of our patients were on treatment for diabetes, hypertension or hyperlipidaemia, factors known to affect the CVR (17)(18)(19), the previously defined non-linear relationship between angiographic stenosis and CVR was maintained and we were able to distinguish between mild, moderate and severe angiographic stenoses as effectively as previous investigators who studied patients with a reduced risk burden compared to ours. In addition in our study, we observed a significant decline of stress MBF compared to rest in regions subtended by arteries with stenoses above 90% of the luminal diameter.…”

“…Inevitably, all patients had at least one risk factor for CAD and seven of our patients at least two. Reduced hyperaemic response and CVR have been reported in asymptomatic individuals with diabetes, hypertension or hyperlipidaemia (17)(18)(19), hence their presence in our patients might have affected our measurements. However, our finding that the previously defined relationship between angiographic stenosis and CVR was maintained and the fact that we were able to distinguish between mild, moderate and severe angiographic stenoses strengthen rather than diminish the significance of our results.…”

The effects of insulin and short-term hyperglycaemia on myocardial blood flow in young men with uncomplicated Type I diabetes

“…Thus, we cannot clearly explain the role of chronic hyperglycaemia on coronary vasoreactivity in this study. This important issue needs further studies including diabetic patients with poor glycaemic control because in our previous PET study [3] diabetic patients with poorer glycaemic control than in this study also had more reduced coronary vasoreactivity.…”

“…During adenosine induced hyperaemia myocardial blood flow value was 23% lower in diabetic than non-diabetic subjects (3.09±0.72 vs 4.0±1.13 ml·g -1 ·min -1 , p<0.05). A significant inverse association was found between adeno- 116 (7) 114 (12) 118 (6) Diastolic BP (mmHg) Non-diabetic 66 (8) 65 (10) 70 (10) DM 72 (8) 72 (8) 76 (5) DM (hg) 69 (9) 70 (10) 67 (7) RPP (mmHg/min) Non-diabetic 6418 (814) We have shown that coronary vasoreactivity is reduced in Type I diabetic patients [3]. The previous PET study was carried out during euglycaemic hyperinsulinaemia (serum insulin ~70 mmol/l) and we found that hyperaemic myocardial blood flow was 29% lower in diabetic than non-diabetic subjects (p<0.05).…”

Abnormal myocardial perfusion and contractile recruitment during exercise in type 1 diabetic patients

“…[1][2][3][4][5] Several anatomical and functional abnormalities of the microcirculation were recognized in the human diabetic heart without obstructive coronary atherosclerosis or coexisting arterial hypertension. 6 Moreover, it has been shown that DM is associated with both reduced coronary flow reserve [7][8][9] and impaired endothelial-dependent epicardial coronary vasodilation. 10 No data are available on the relationship between myocardial perfusion and left ventricular (LV) function in T1DM that may constitute a factor leading to progressive contractile dysfunction.…”