Left ventricular function and energy homeostasis in patients with type 1 diabetes with and without microvascular complications

BACKGROUND: This study was performed to assess left ventricular (LV) energy metabolism and function in patients with type 1 diabetes with or without overt microvascular complications. METHODS: We performed cardiac Magnetic Resonance Imaging (MRI) and (31)P spectroscopy (MRS) in 24 patients with overt microvascular complications and in 15 carefully selected patients without complications in spite of a long duration of the disease (>20years) and matched for anthropometric features. 31 healthy subjects served as a control group. RESULTS: Systolic function was preserved in all study subjects. Patients with overt complications showed a higher LV wall mass/end diastolic volume ratio and altered parameters of diastolic function when compared to patients without complications and to controls. They were also characterized by lower PCr/ATP ratio (a recognized marker of energy metabolism). No effect of HbA1c was detected within groups. CONCLUSIONS: In patients with type 1 diabetes 1) overt microvascular complications were associated with altered LV geometry, diastolic function and energy metabolism 2) in patients without complications and duration of disease >20years no association with these alterations were found despite poor glycemic control. The features of this highly selected subgroup of patients demonstrated that long lasting chronic hyperglycemia per se is not sufficient to induce abnormality of cardiac energy metabolism and that additional yet to be identified (metabolic or genetic) factors must be important contributing factors.