I-123 MIBG MYOCARDIAL SCINTIGRAPHY IN DIABETIC-PATIENTS - RELATIONSHIP TO AUTONOMIC NEUROPATHY

The aim of this study was to investigate the relationship between auto nomic nerve dysfunction and myocardial uptake of I-123-meta-iodobenzyl guanidine (MIBG) in patients with diabetes mellitus. Twenty-two non-i nsulin-dependent diabetic patients, 9 with autonomic neuropathy [ANP()] and 13 without autonomic neuropathy [ANP(-)], and 8 controls were i ncluded in the study. Both planar and single photon emission tomograph ic (SPET) images were obtained 30 min (early) and 3 h (delayed) after the I-123-MIBG injection. The heart-to-mediastinal uptake ratio (H/M) and the washout ratio of I-123-MIBG (%WR) were calculated from planar images. The uptake ratio of the inferior wall to the anterior wall. (I /A) and the %WR of both the inferior and anterior walls were calculate d from the SPET images. On the early planar images, the mean H/M ratio in the ANP(+) group was significantly lower than that of the control group. The mean %WR on the planar images in the ANP(-) group was signi ficantly higher than that of the controls. The SPET images demonstrate d a reduction in MIBG uptake and significantly increased clearance in the inferior wall of the ANP(-) patients. These findings extended to o ther areas of the heart in the ANP(+) patients. In the quantitative an alysis of the SPET images, the ANP(+) group had significantly lower I/ A values and significantly higher %WR values in the anterior wall. The ANP(+) group showed significantly increased clearance of I-123-MIBG i n the inferior wall. We conclude that I-123-MIBG myocardial scintigrap hy is a useful diagnostic tool both in the early detection and evaluat ion of the progression of myocardial sympathetic nerve dysfunction in patients with diabetes mellitus. Both the I/A and %WR calculated from SPET images are useful parameters.