Event-related potentials (P300, mismatch negativity) in diabetes mellitus

P300 and mismatch negativity were measured in 10 patients with noninsulin-dependent diabetes mellitus and 10 age-matched healthy controls. The latencies of N200 and P300 were significantly longer, and the amplitudes of N200 and P300 were significantly smaller in the diabetes mellitus group than in the healthy control group. The latency of mismatch negativity did not show any significant difference between the two groups. The amplitude of mismatch negativity was significantly smaller in the diabetes mellitus group than in the healthy control group. The present study suggests that cognitive function and automatic comparison process between the standard auditory stimulus and the deviant auditory stimulus are abnormal in patients with non-insulin-dependent diabetes mellitus without abnormality on head magnetic resonance imaging.