Early myocardial impairment in type 1 diabetes patients without known heart disease assessed with tissue Doppler echocardiography: The Thousand & 1 study

PURPOSE: Cardiovascular disease is the most common cause of mortality in type 1 diabetes; patients with albuminuria are at greatest risk. We investigated myocardial function and premature myocardial impairment in type 1 diabetes patients with and without albuminuria compared to controls.

METHODS: This study included a cross-sectional survey of 1093 type 1 diabetes patients from Steno Diabetes Center and 200 healthy controls. Conventional and tissue Doppler echocardiographic measurements were analysed in multivariable models in normoalbuminuria (n = 760), microalbuminuria (n = 227) and macroalbuminuria (n = 106). Investigators were blinded to degree of albuminuria.

RESULTS: For the type 1 diabetes patients, mean age was 49.6 years, 53% were men and mean diabetes duration was 25.5 years. In multivariable models systolic velocity s' did not differ between type 1 diabetes patients with normoalbuminuria and controls (β-coefficient [95% confidence interval]: -0.17 [-0.41; 0.08], p = 0.19), but was impaired between controls and microalbuminuria (-0.53 [-0.84; -0.23], p = 0.001) and macroalbuminuria (-0.59 [-0.96; -0.22], p = 0.002). Diastolic measurements (e', a', e'/a', and E/e') were all significantly impaired in type 1 diabetes, for example, e'/a': normoalbuminuria, microalbuminuria and macroalbuminuria versus controls: -0.38 [-0.52; -0.23], p < 0.001; -0.49 [-0.67; -0.32], p < 0.001; and -0.81 [-1.03; -0.59], p < 0.001. In age-related analyses, myocardial impairment occurred prematurely in type 1 diabetes compared to controls (e.g. E/e' = 8; 9.2 years [normoalbuminuria], 17.3 years [microalbuminuria] and 41.4 years [macroalbuminuria] prematurely, respectively).

CONCLUSION: In type 1 diabetes patients with albuminuria, both systolic and diastolic functions are impaired, whereas in patients without albuminuria only diastolic function is affected. Myocardial impairment is detectable many years prematurely in type 1 diabetes, especially in patients with albuminuria.