Reduced myocardial 123I-metaiodobenzylguanidine uptake in newly diagnosed IDDM patients.
123I-labeled metaiodobenzylguanidine (123I-MIBG) scintigraphy is a novel technique for the assessment of cardiac sympathetic dysinnervation. To evaluate defects of the cardiac autonomic nervous system at the onset of IDDM, this technique together with conventional electrocardiogram (ECG)-based cardiac reflex tests and measurement of the QT interval was applied to 22 newly diagnosed metabolically stabilized IDDM patients without myocardial perfusion abnormalities (99mTc-labeled methoxyisobutylisonitrile scintigraphy) and 9 matched control subjects. Seventeen diabetic patients (77%), but none of the control subjects, were observed to have a reduced global myocardial uptake of 123I-MIBG. In contrast, only two diabetic patients (9%) demonstrated an ECG-based cardiac autonomic neuropathy (two or more of five age-related cardiac reflex tests abnormal) (P < 0.001). In newly diagnosed IDDM patients, the uptake of 123I-MIBG was reduced more in the posterior myocardial region compared with the lateral and apical region (P < 0.01, P = 0.03). The septal myocardial region exhibited a smaller uptake than the lateral myocardial region (P = 0.02). The maximum/minimum 30:15 ratio correlated with the global, anterior, lateral, and septal myocardial uptake of 123I-MIBG (P < 0.05, P < 0.05, P < 0.01, P < 0.05). A correlation between global and regional myocardial 123I-MIBG uptake and HbA1c or QT interval was not observed. Newly diagnosed metabolically stabilized IDDM patients without myocardial perfusion defects show evidence of cardiac sympathetic dysinnervation, as indicated by a reduction of 123I-MIBG uptake, at a significant higher proportion than ECG-based cardiac autonomic neuropathy. Furthermore, they present with regional differences of myocardial 123I-MIBG uptake.
Schnell
O
O
Diabetes Research Institute, Schwabing City Hospital, Munich, Germany.
Muhr
D
D
Weiss
M
M
Dresel
S
S
Haslbeck
M
M
Standl
E
E
D019797:3-Iodobenzylguanidine; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D003287:Contrast Media; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007462:Iodobenzenes / Q000493:pharmacokinetics*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D011877:Radionuclide Imaging; D012119:Respiration; D013599:Systole; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics; D014636:Valsalva Maneuver
D001786:Blood Glucose; D003287:Contrast Media; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine; D017256:Technetium Tc 99m Sestamibi