Aortic Stiffness in Insulin‐dependent Diabetics: An Echocardiographic Study

To assess the aortic stiffness (AS) in young (15–35 year old) insulin-dependent diabetics without manifestations of atherosclerotic disease or hypertension, M-mode echocardiography was used to measure relative changes in aortic diameter expressed as Aortic strain = Diameter change/Diastolic diameter x 100% Aortic stiffness can be calculated from the formula AS = Pulse pressure/Aortic strain. Fifty-seven diabetics were investigated, 31 men (aged 23.6 ± 5.6 years, mean ± SD) and 26 women (aged 25.7 ± 6.4 years). There were 26 healthy controls with similar blood pressure, 14 men (aged 25.0 ± 5.5 years) and 12 women (aged 24.6 ± 7.1). The AS in diabetic men was 14 ± 8.0 (mean ± SD) compared to 3.6 ± 0.7 in controls (p<0.001). In diabetic women the AS was 5.8 ± 3.1 compared to 4.3 ± 1.3 in controls (p<0.05). Diabetic men also had much stiffer aortas than diabetic women (p<0.001). There was a linear correlation between AS and duration of diabetes in men (R= 0.70; (p<0.001). For females no such correlation was found, the AS frequently being within the range of the controls in spite of long duration of the disease. In males there was a significant correlation between AS and retinopathy (R = 0.49; p<0.01) and an inverse correlation with HDL-cholesterol/total cholesterol ratio (R = 0.51; p<0.01). In diabetic females AS was significantly greater in smokers (7.0 ± 3.7) than in non-smokers (4.2 ± 2.2; p<0.01). In neither sex were there significant correlations between AS and post-prandial blood glucose, HbA1c, triglycerides or total cholesterol. The results show that AS frequently increases at a young age in insulin-dependent diabetics, especially males, who on average double the stiffness increment every 7.5 years of the disease.