Cardiac autonomic dysfunction and cardiac microvascular dysfunction are diabetic complications associated with increased mortality, but the association between these have been difficult to assess. We applied new and sensitive methods to assess this in type 2 diabetic patients.
In a cross-sectional design, coronary flow reserve (CFR) assessed by cardiac 82Rb-positron-emission-tomography/computed-tomography, cardiac autonomic reflex tests and heart-rate variability indices were performed in 55 patients with type 2 diabetes, without cardiovascular disease, and 28 controls. Cardiac 123I-metaiodobenzylguanidine-scintigraphy (MIBG) was conducted in a subgroup of 29 patients and 14 controls, and evaluated as the late heart/mediastinum-ratio and washout rate.
Impaired function of all the cardiac autonomic measures (except the washout rate) was associated with reduced CFR. A heart-rate variability index reflecting both sympathetic and parasympathetic function (low-frequency power) and the late heart/mediastinum-ratio (reflecting the function of adrenergic receptors and sympathetic activity) were positively correlated with CFR after age and heart-rate adjustment. The late heart/mediastinum-ratio remained correlated with CFR after further adjustment.
In type 2 diabetic patients without cardiovascular disease, we demonstrate an independent association between cardiac autonomic function and CFR. We suggest that a reduced cardiac autonomic function and damage to the adrenergic receptors may contribute to the development of cardiac microvascular dysfunction.
- Received April 4, 2016.
- Accepted June 22, 2016.
- © 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.