INFLUENCE OF FASTING ON HEART-RATE-VARIABILITY IN DIABETIC-PATIENTS WITH DIFFERENT DEGREES OF CARDIOVASCULAR AUTONOMIC NEUROPATHY

Effects of fasting on the cardiovascular system in diabetes are not su fficiently described. We assessed possible influence of fasting period s exceeding 13 hrs on heart rate variability (HRV) as compared to a sh ort postprandial period in diabetic patients and controls. Short-term spectral analysis of HRV was used either in a common postprandial/post absorptive state (interval since the last meal 146+/-11 min) or during the fasting day (interval 1072+/-22 min) in 56 diabetic patients with different degrees of cardiovascular autonomic neuropathy and in 15 no n-diabetic control persons comparable in age, body mass index and gend er. Easting resulted in diabetic patients with all degrees of cardiova scular autonomic neuropathy (including its definite form) in an increa se of cumulative spectral power of total frequency band from 7.4+/-0.2 to 7.9+/-0.2 ln [ms(2)], p<0.001, of low-frequency band from 6.6+/-0. 2 to 6.9+/-0.2 ln [ms(2)], p=0.004, and of high-frequency band from 6. 5+/-0.2 to 7.3+/-0.2 ln [ms(2)], p<0.001, and in an increase of parame ters of time-domain analysis (p<0.001) as well. In contrast, nondiabet ic control group displayed only a non-significant increase of HRV (p=0 .19), We conclude that fasting increases HRV in diabetic patients, mai nly due to an increase of vagal tone, In any interpretation of short-t erm spectral analysis of HRV the interval since the last meal should b e considered. We propose a standardization of this interval. (C) 1997, Editrice Kurtis.