Myocardial glucose uptake in patients with insulin-dependent diabetes mellitus assessed quantitatively by dynamic positron emission tomography.

BACKGROUND

Animal studies have demonstrated reduced myocardial glucose utilization in the diabetic heart, suggesting abnormalities in glucose transport. This study was designed to evaluate myocardial glucose uptake as assessed by 2-fluoro-(fluorine-18)2-deoxy-D-glucose (FDG) and positron emission tomography (PET) in patients with insulin-dependent diabetes mellitus (IDDM) under standardized metabolic conditions.

METHODS AND RESULTS

A hyperinsulinemic-euglycemic clamp technique was used during PET data acquisition in nine healthy male volunteers and seven young male patients with a history of IDDM for less than 5 years. Oxidative metabolism was assessed with C-11 acetate, and glucose uptake was quantitatively measured with FDG using Patlak graphic analysis. Hemodynamic data and C-11 acetate kinetics were comparable. Myocardial glucose uptake averaged 0.44 +/- 0.12 mumol.g-1.min-1 in normal subjects and 0.43 +/- 0.16 mumol.g-1.min-1 in patients with IDDM (P = NS). Blood tracer clearance was also similar in both groups as determined by the ratio of peak blood tracer activity to the activity at 55 to 60 minutes after tracer injection. F-18 activity ratio between myocardium and blood pool averaged 7.2 +/- 3.4 in the normal heart and 7.5 +/- 3.0 in the diabetic heart (P = NS).

CONCLUSIONS

These data indicate that metabolic standardization and supplementation with insulin in young patients with IDDM is associated with myocardial glucose uptake similar to that observed in the normal heart. Chronic therapy with insulin may prevent the metabolic abnormalities observed in diabetic animal models.