Glucose ingestion affects cardiac ANS in healthy subjects with different amounts of body fat.

Abstract

Low-to-high frequency ratio (LF/HF) is an indirect index of sympathovagal balance derived by heart rate spectral analysis. We investigated the effect of glucose ingestion on LF/HF in 17 healthy, normotensive young subjects (9 male, 8 female) with a wide body fat content range (body fat = 29 +/- 5.9%; range = 19-42%) and a normal thyroid hormone status. Before and after an oral glucose tolerance test (OGTT), the Holter technique and indirect calorimetry allowed us to determine heart rate and substrate oxidation in all subjects. At baseline, LF/HF correlated with body fat (r = 0.60, P < 0.005), waist-to-hip ratio (r = 0.57, P < 0.01), fasting plasma insulin (r = 0.55, P < 0.04), leptin (r = 0.56, P < 0.01), and norepinephrine (r = 0.58, P < 0.009) concentrations. Age-, body fat-, content-, and fat-free mass-adjusted respiratory quotient (r = 0.59, P < 0.007) and basal metabolic rate (r = 0.61, P < 0.001) were also correlated with basal LF/HF. Along with OGTT plasma glucose, insulin and norepinephrine concentrations and basal LF/HF significantly rose at 60 min and then declined throughout the test. Area under the curve (AUC) for LF/HF correlated with body fat (r = -0.66, P < 0.004), fasting plasma leptin concentration (r = -0.57, P < 0.01), glucose induced thermogenesis (r = 0.62, P < 0.001), glucose uptake (r = 0.59, P < 0.007), and AUC for plasma norepinephrine concentration (r = 0.63, P < 0.001). Water instead of glucose ingestion does not significantly affect LF/HF (n = 8). In conclusion, our study supports the hypothesis that glucose ingestion affects LF/HF and that such change is related to the amount of body fat.

Effects of Nutrient Composition of Dinner on Sleep Architecture and Energy Metabolism during Sleep

“…Sleep stage and energy expenditure are strongly regulated by autonomic nervous system activity (35,36). Because effects of the nutrient composition of the meal on parasympathetic and sympathetic nervous system activity had been reported (37,38), indices of autonomic nervous system activity were also measured in the present study.…”

Effects of Increased Physical Activity and Mild Calorie Restriction on Heart Rate Variability in Obese Women.

“…[33][34][35] Insulin is reported to enhance sympathetic activity 10,31,36) and the relation between central obesity and insulin resistance 37) may at least in part explain the association between the changes in HRV variables, the SD of RR interval and HF, and HOMA IR , an index of insulin resistance. Further studies are required to clarify the role of insulin resistance in the improvement of autonomic modulation after weight reduction.…”

Sugary drinks in the pathogenesis of obesity and cardiovascular diseases

“…Several studies in humans have determined the acute effects of glucose and fructose intake on sympathetic activity and regional blood flow. Although both glucose and fructose result in cardiac sympathetic activation with a subsequent increase in heart rate, [63][64][65] there are important differences between these monosaccharides regarding their effects on vascular tone. Whereas glucose infusion augments muscle nerve sympathetic activity and causes vasodilatation in skeletal muscle, infusion of fructose does not.…”