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Cardiac abnormalities in type 1 diabetes
G de Simone1, G F Mureddu, O Vaccaro
1Department of Clinical and Experimental Medicine, Federico II, University Hospital School of Medicine, Naples, Italy. simogi@unina.it
Insights
Type 1 diabetes in normotensive adults leads to increased left ventricular (LV) mass and supernormal systolic function. However, diastolic function shows impaired relaxation despite normal chamber stiffness.
Area of Science:
- Cardiology
- Diabetology
- Medical Imaging
Background:
- Type 1 diabetes mellitus (T1DM) can affect cardiovascular health.
- Left ventricular (LV) structural and hemodynamic changes in T1DM are not fully understood.
Purpose of the Study:
- To evaluate LV geometry, systolic, and diastolic function in patients with T1DM.
- To compare these parameters with age- and sex-matched healthy controls.
Main Methods:
- Doppler echocardiography was performed in 40 normotensive T1DM patients and 40 controls.
- Patients had no coronary heart disease or valvular lesions.
- A case-control design was employed.
Main Results:
- T1DM patients showed increased LV mass and dimension but normal relative wall thickness.
- LV ejection fraction and midwall shortening were supernormal in T1DM patients.
- Diastolic function revealed prolonged isovolumic relaxation time and impaired active relaxation, despite normal chamber stiffness.
Conclusions:
- Normotensive T1DM patients exhibit moderate LV mass increase and supernormal systolic function.
- LV active relaxation is impaired, but chamber stiffness remains normal.
- These findings are independent of disease duration, glycosylated hemoglobin, or target organ damage.
Background:
Left ventricular (LV) structural and hemodynamic consequences of type 1 diabetes mellitus are not fully understood.
Methods:
To evaluate LV geometry, systolic and diastolic function in type 1 diabetes, Doppler echocardiograms were performed in 40 normotensive, type 1 diabetic patients without coronary heart disease or valvular lesions (22 men, 18 women, mean age 43 +/- 6 years, body mass index 24.7 +/- 2.8 kg/m2) and in 40 age and sex-matched non-diabetic normotensive controls (22 men, 18 women, mean age 43 +/- 5 years, body mass index 23.2 +/- 2.8 kg/m2), in a case-control design.
Results:
Patients had higher systolic blood pressure than controls (p < 0.03) and comparable diastolic blood pressure and heart rate. LV dimension and mass were higher in patients than in controls (both p < 0.0001) whereas relative wall thickness did not differ. For comparable levels of end-systolic stress, patients exhibited a higher ejection fraction than controls (p < 0.01) and normal midwall shortening. Cardiac output was also higher (p < 0.001), whereas total peripheral resistance was lower in patients than in controls (p < 0.0001). Isovolumic relaxation time and E deceleration were prolonged in patients and peak A velocity was greater than in controls (all p < 0.01), whereas the difference in duration between A and pulmonary vein peak reverse flow at atrial contraction was comparable. In subgroup analyses, all reported features were independent of a) presence of target organ damage; b) duration of disease; c) levels of glycosylated hemoglobin.
Conclusions:
In normotensive patients with type 1 diabetes: 1) there was a moderate increase in LV mass; 2) LV chamber function was supernormal and wall mechanics was normal; 3) LV active relaxation was impaired but chamber stiffness was normal.