of 3Internal Medicine, Medical Centre Alkmaar.

Myocardial effects of hyperglycemia Objective: To evaluate the effects of hyperglycemia due to partial insulin deprivation on myocardial triglyceride (TG) content and myocardial function in patients with type 1 diabetes. Research Design and Methods: Myocardial TG content and left ventricular (LV) function were measured by magnetic resonance (MR) spectroscopy and MR imaging during optimal glucoregulation and after 24 hours of partial insulin deprivation (n=10). Results: Mean insulin infusion rate was 45 ± 5 units at baseline, whereas it was 27 ± 5 units during hyperglycemia (per 24 hours, P < 0.001). Plasma glucose levels increased from 8.4 ± 0.6 to 15.9 ± 0.8 mmol/l (P < 0.001), and plasma levels of non-esterified fatty acids from 0.31 ± 0.05 to 0.46 ± 0.07 mmol/l (P = 0.015). Hyperglycemia had no effects on myocardial TG content and LV function. Conclusions: Short-term hyperglycemic dysregulation does not modulate myocardial TG content or myocardial function, despite considerable metabolic adaptations. 2 Myocardial effects of hyperglycemi