Long-term effect of epalrestat on cardiac autonomic neuropathy in subjects with non-insulin dependent diabetes mellitus.

To evaluate the effect of long-term administration of an aldose reductase inhibitor on diabetic cardiovascular autonomic neuropathy, 22 subjects with non-insulin dependent diabetes mellitus (NIDDM, 11 men and 11 women, mean age; 64.8 +/- 7.8 years, duration of diabetes; 18.3 +/- 5.6 years) were administered epalrestat, one type of aldose reductase inhibitor, for 36 months. The changes in the coefficient of variation of the R-R interval (CV(R R)) during rest and the QTc interval were compared with 43 age-matched NIDDM (controls). During the study, the CV(R R) value gradually decreased in the controls, while it slightly increased in subjects treated with epalrestat. After 36 months, the CV(R R) value (2.31 +/- 1.09%) in subjects treated with epalrestat was significantly (P < 0.05) higher than that (1.84 +/- 0.75%) in the controls. There were no significant differences in QTc intervals in both groups. These results suggest that long-term administration of an aldose reductase inhibitor may be available for cardiac autonomic neuropathy in even relatively older diabetic subjects with long duration.