["Beat to beat" variations in diabetic patients].

Our aim is to find a way to test the autonomic nervous dysfunction in diabetes mellitus by performing maximal deep-breathings during ECg recording. The subjects underwent ECG recording continously for 2 minutes: during the first minute they breathed regularly, in the second minute they accomplished 6 maximal deep breathings. The R-R intervals in the 1st, as well as the shortest R-R intervals during inspiration and the longest ones during expiration in the second minute were measured and expiration-inspiration ratio (E:I ratio) was calculated. A decreased variation of the R-R intervals from deep-breathings reveals the autonomic nervouis dysfunction . Our data suggest that in diabetes mellitus, R-R intervals show a decreased variation, able to demonstrate earlier autonomic neuropathy.