Sympathetic dysfunction in type 1 diabetes: Association with impaired myocardial blood flow reserve and diastolic dysfunction

Objectives This study was designed to explore the relationships of early diabetic microangiopathy to alterations of cardiac sympathetic tone and myocardial blood flow (MBF) regulation in subjects with stable type 1 diabetes. Background In diabetes, augmented cardiac sympathetic tone and abnormal MBF regulation may predispose to myocardial injury and enhanced cardiac risk. Methods Subject groups comprised healthy controls (C) (n = 10), healthy diabetic subjects (DC) (n = 12), and diabetic subjects with very early diabetic microangiopathy (DMA+) (n = 16). [ 11 C] meta -hydroxyephedrine ([ 11 C]HED) and positron emission tomography (PET) were used to explore left ventricular (LV) sympathetic integrity and [ 13 N]ammonia-PET to assess MBF regulation in response to cold pressor testing (CPT) and adenosine infusion. Results Deficits of LV [ 11 C]HED retention were extensive and global in the DMA+ subjects (36 ± 31% vs. 1 ± 1% in DC subjects; p Conclusions Augmented cardiac sympathetic tone and responsiveness and impaired myocardial perfusion may contribute to myocardial injury in diabetes.