Effects of glucose ingestion on cardiac autonomic nervous system in healthy centenarians: differences with aged subjects.
BACKGROUND
Spectral analysis of heart rate variability (HRV) investigates the cardiac autonomic nervous system (ANS) activity. In particular, low frequency/high frequency (LF/HF) is considered an index of cardiac sympatho-vagal balance and is stimulated by glucose ingestion in healthy subjects. No studies have evaluated the effect of glucose ingestion on cardiac ANS in centenarians.


METHODS
In 30 healthy centenarians (HC) and 25 aged subjects (AS) power spectral analysis of HRV was investigated during an oral glucose ingestion.


RESULTS
Glucose ingestion rose LF/HF ratio in both groups studied. Such stimulatory effects were restrained to the first 60 min of the study. Independent of age, gender, body mass index (BMI) and fasting plasma norepinephrine and FT3 concentrations, HC had basal total power (1318 +/- 546 vs. 1918 +/- 818 msec2, P < 0.01), lower low frequency (LF) (33 +/- 21 vs. 50 +/- 11 n.u., P < 0. 03), and higher high frequency (HF) (74 +/- 18 vs. 43 +/- 15 n.u., P < 0.05) than AS. Consequently, LF/HF ratio (0.43 +/- 0.07 vs. 0.91 +/- 0.05, P < 0.02) was also lower in HC than in AS. In AS, but not in HC, the baseline LF/HF ratio correlated significantly with BMI (r = 0.48, P < 0.01), waist-hip-ratio (WHR) (r = 0.45, P < 0.02), fasting plasma insulin (r = 0.49, P < 0.01) and norepinephrine (r = 0.57, P < 0.02) concentration. Glucose ingestion was associated with a significant rise in LF/HF ratio in both groups studied but per cent changes in glucose mediated stimulation of LF/HF was lower in HC than in AS. In a control study, water administration did not affect power spectral parameters of HRV.


CONCLUSIONS
Our study demonstrates that basal- and glucose-stimulated LF/HF, an indirect index of cardiac sympatho-vagal balance, are lower in HC than in AS.
Paolisso
G
G
University of Naples, Naples, Italy. gpaoliss@tin.it
Manzella
D
D
Rizzo
M R
MR
Barbieri
M
M
Gambardella
A
A
Varricchio
M
M
D000368:Aged / Q000502:physiology*; D000369:Aged, 80 and over / Q000502:physiology*; D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002784:Cholesterol / Q000097:blood; D004040:Dietary Carbohydrates; D004837:Epinephrine / Q000097:blood; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D006321:Heart / Q000294:innervation*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000097:blood*; D020738:Leptin / Q000097:blood; D008297:Male; D009638:Norepinephrine / Q000097:blood; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D004040:Dietary Carbohydrates; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D020738:Leptin; D014280:Triglycerides; D002784:Cholesterol; D005947:Glucose; D009638:Norepinephrine; D004837:Epinephrine