Long-term effect of acetyl-L-carnitine on myocardial I-123-MIBG uptake in patients with diabetes

Carnitine derivatives may have beneficial effects on cardiac and nerve func tion in patients with diabetes. The aim of this study was to investigate th e effect of acetyl-L-carnitine (ALC) on myocardial sympathetic nervous func tion as measured with I-123-meta-iodobenzyl guanidine (MIBG) and single-pho ton emission tomography (SPET) in 19 patients with diabetes (placebo group, n = 6; ALC group, n = 13) at the beginning and at the end of a 1-year rand omized, placebo-controlled, double-blind trial. The coefficient of variatio n for the MIBG analysis was 4%. In patients who were given a placebo, globa l myocardial MIBG uptake deteriorated during the study (MIBG uptake 1-year follow-up/baseline, 0.86 +/- 0.05, mean +/- standard error of mean), wherea s in patients treated with ALC, MIBG uptake did not change significantly (1 -year follow-up/baseline, 1.07 +/- 0.08; p = 0.03 between the groups). On t he basis of these preliminary data, we conclude that long-term treatment wi th ALC may be of potential value in preventing the progressive loss of myoc ardial sympathetic nervous function in patients with diabetes. MIBG-SPET is a sensitive and thus valuable method in assessing the development of myoca rdial sympathetic nervous dysfunction.