0
selected
-
1.
Effect of 48 h Fasting on Autonomic Function, Brain Activity, Cognition, and Mood in Amateur Weight Lifters.
Solianik, R, Sujeta, A, Terentjevienė, A, Skurvydas, A
BioMed research international. 2016;:1503956
Abstract
Objectives. The acute fasting-induced cardiovascular autonomic response and its effect on cognition and mood remain debatable. Thus, the main purpose of this study was to estimate the effect of a 48 h, zero-calorie diet on autonomic function, brain activity, cognition, and mood in amateur weight lifters. Methods. Nine participants completed a 48 h, zero-calorie diet program. Cardiovascular autonomic function, resting frontal brain activity, cognitive performance, and mood were evaluated before and after fasting. Results. Fasting decreased (p < 0.05) weight, heart rate, and systolic blood pressure, whereas no changes were evident regarding any of the measured heart rate variability indices. Fasting decreased (p < 0.05) the concentration of oxygenated hemoglobin and improved (p < 0.05) mental flexibility and shifting set, whereas no changes were observed in working memory, visuospatial discrimination, and spatial orientation ability. Fasting also increased (p < 0.05) anger, whereas other mood states were not affected by it. Conclusions. 48 h fasting resulted in higher parasympathetic activity and decreased resting frontal brain activity, increased anger, and improved prefrontal-cortex-related cognitive functions, such as mental flexibility and set shifting, in amateur weight lifters. In contrast, hippocampus-related cognitive functions were not affected by it.
-
2.
Effects of outdoor temperature on changes in physiological variables before and after lunch in healthy women.
Okada, M, Kakehashi, M
International journal of biometeorology. 2014;(9):1973-81
-
-
Free full text
-
Abstract
Previous studies of autonomic nervous system responses before and after eating when controlling patient conditions and room temperature have provided inconsistent results. We hypothesized that several physiological parameters reflecting autonomic activity are affected by outdoor temperature before and after a meal. We measured the following physiological variables before and after a fixed meal in 53 healthy Japanese women: skin temperature, systolic and diastolic blood pressure, salivary amylase, blood glucose, heart rate, and heart rate variability. We assessed satiety before and after lunch using a visual analog scale (100 mm). We recorded outdoor temperature, atmospheric pressure, and relative humidity. Skin temperature rose significantly 1 h after eating (greater in cold weather) (P = 0.008). Cold weather markedly influenced changes in diastolic blood pressure before (P = 0.017) and after lunch (P = 0.013). Fasting salivary amylase activity increased significantly in cold weather but fell significantly after lunch (significantly greater in cold weather) (P = 0.007). Salivary amylase was significantly associated with cold weather, low atmospheric pressure, and low relative humidity 30 min after lunch (P < 0.05). Cold weather significantly influenced heart rate variability (P = 0.001). The decreased low frequency (LF)/high frequency (HF) ratio, increased Δ LF/HF ratio, and increased Δ salivary amylase activity imply that cold outdoor temperature is associated with dominant parasympathetic activity after lunch. Our results clarify the relationship between environmental factors, food intake, and autonomic system and physiological variables, which helps our understanding of homeostasis and metabolism.
-
3.
Effects of prior intensive insulin therapy on cardiac autonomic nervous system function in type 1 diabetes mellitus: the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study (DCCT/EDIC).
Pop-Busui, R, Low, PA, Waberski, BH, Martin, CL, Albers, JW, Feldman, EL, Sommer, C, Cleary, PA, Lachin, JM, Herman, WH, et al
Circulation. 2009;(22):2886-93
-
-
Free full text
-
Abstract
BACKGROUND The Epidemiology of Diabetes Interventions and Complications (EDIC) study, a prospective observational follow-up of the Diabetes Control and Complications Trial (DCCT) cohort, reported persistent benefit of prior intensive therapy on retinopathy and nephropathy in type 1 diabetes mellitus. We evaluated the effects of prior intensive insulin therapy on the prevalence and incidence of cardiac autonomic neuropathy (CAN) in former DCCT intensive and conventional therapy subjects 13 to 14 years after DCCT closeout. METHODS AND RESULTS DCCT autonomic measures (R-R variation with paced breathing, Valsalva ratio, postural blood pressure changes, and autonomic symptoms) were repeated in 1226 EDIC subjects in EDIC year 13/14. Logistic regression models were used to calculate the odds of incident CAN by DCCT treatment group after adjustment for DCCT baseline covariates, duration in the DCCT, and quantitative autonomic measures at DCCT closeout. In EDIC year 13/14, the prevalence of CAN using the DCCT composite definition was significantly lower in the former intensive group versus the former conventional group (28.9% versus 35.2%; P=0.018). Adjusted R-R variation was significantly greater in the former DCCT intensive versus the former conventional group (29.9 versus 25.9; P<0.001). Prior DCCT intensive therapy reduced the risks of incident CAN by 31% (odds ratio, 0.69; 95% confidence interval, 0.51 to 0.93) and of incident abnormal R-R variation by 30% (odds ratio, 0.70; 95% confidence interval, 0.51 to 0.96) in EDIC year 13/14. CONCLUSIONS Although CAN prevalence increased in both groups, the incidence was significantly lower in the former intensive group compared with the former conventional group. The benefits of former intensive therapy extend to measures of CAN up to 14 years after DCCT closeout.
-
4.
Cardiac resynchronization therapy upregulates cardiac autonomic control.
Cha, YM, Oh, J, Miyazaki, C, Hayes, DL, Rea, RF, Shen, WK, Asirvatham, SJ, Kemp, BJ, Hodge, DO, Chen, PS, et al
Journal of cardiovascular electrophysiology. 2008;(10):1045-52
-
-
Free full text
-
Abstract
OBJECTIVE To determine the effect of cardiac resynchronization therapy (CRT) on sympathetic nervous function in heart failure (HF). BACKGROUND Neurohormonal dysregulation and cardiac autonomic dysfunction are associated with HF and contribute to HF progression and its poor prognosis. We hypothesized that mechanical resynchronization improves cardiac sympathetic function in HF. METHODS Sixteen consecutive patients receiving CRT for advanced cardiomyopathy and 10 controls were included in this prospective study. NYHA class, 6-minute walk distance, echocardiographic parameters, plasma norepinephrine (NE) were assessed at baseline, 3-month and 6-month follow-up. Cardiac sympathetic function was determined by (123)iodine metaiodobenzylguanidine ((123)I-MIBG) scintigraphy and 24-hour ambulatory electrocardiography. RESULTS Along with improvement in NYHA class (3.1 +/- 0.3 to 2.1 +/- 0.4, P < 0.001) and LVEF (23 +/- 6% to 33 +/- 12%, P < 0.001), delayed heart/mediastinum (H/M) (123)I-MIBG ratio increased significantly (1.8 +/- 0.7 to 2.1 +/- 0.6, P = 0.04) while the H/M (123)I-MIBG washout rate decreased significantly (54 +/- 25% to 34 +/- 24%, P = 0.01) from baseline to 6-month follow-up. The heart rate variability (HRV) measured in SD of normal-to-normal intervals also increased significantly from baseline (82 +/- 30 ms) to follow-up (111 +/- 32 ms, P = 0.04). The improvement in NYHA after CRT was significantly associated with baseline (123)I-MIBG H/M washout rate (r = 0.65, P = 0.03). The improvement in LVESV index was associated with baseline (123)I-MIBG delayed H/M ratio (r =-0.67, P = 0.02) and H/M washout rate (r = 0.65, P = 0.03). CONCLUSION After CRT, improvements in cardiac symptoms and LV function were accompanied by rebalanced cardiac autonomic control as measured by (123)I-MIBG and HRV.
-
5.
Impact of diet-induced weight loss on the cardiac autonomic nervous system in severe obesity.
Poirier, P, Hernandez, TL, Weil, KM, Shepard, TJ, Eckel, RH
Obesity research. 2003;(9):1040-7
Abstract
OBJECTIVE To determine the impact of diet-induced weight loss on cardiac autonomic nervous system modulation and arrhythmias in subjects with severe obesity and the influence of a high-fat or a high-carbohydrate diet regimen on heart rate variability in reduced-obese individuals. RESEARCH METHODS AND PROCEDURES Eight severely obese subjects (BMI > or = 40.0 kg/m(2)) underwent a 3-month weight loss program followed by a 3-month reduced-weight maintenance regimen. Thereafter, each subject was admitted for an inpatient period of 17 days on two separate occasions. A high-carbohydrate (60%) or high-fat (55%) diet of appropriate energy content for weight maintenance was prescribed during each inpatient phase. Heart rate variability was derived from a 24-hour Holter monitoring system in all subjects during their inpatient stay. Cardiac Holter monitoring was performed at three occasions (baseline, diet phase I, and diet phase II), including the second night of a two overnight calorimetry chamber stay. RESULTS After the diet regimen, there was a 10% decrease in weight. There were no significant changes in systolic and diastolic blood pressure, arrhythmias, glucose, insulin, total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, respiratory exchange ratio, and resting energy expenditure between experiments. Mean heart rate was lower after weight loss compared with baseline (p < 0.001). After weight loss, there was an increase in the parasympathetic indices of heart rate variability showing an increase in cardiac vagal modulation (all p < 0.05). DISCUSSION Weight loss is associated with significant improvement in autonomic cardiac modulation through enhancement of parasympathetic modulation, which clinically translates into a decrease in heart rate.
-
6.
Effects of physical training on the recovery of the autonomic nervous activity during exercise after coronary artery bypass grafting: effects of physical training after CABG.
Takeyama, J, Itoh, H, Kato, M, Koike, A, Aoki, K, Fu, LT, Watanabe, H, Nagayama, M, Katagiri, T
Japanese circulation journal. 2000;(11):809-13
Abstract
Analysis of heart rate variability (HRV) can identify patients at risk of sudden cardiac death after myocardial infarction. The present study examined the effect of 2 weeks of supervised aerobic exercise training on the recovery of the autonomic nervous activity, exercise capacity, and cardiac output (CO) after coronary artery bypass grafting (CABG). Twenty-eight patients were randomly divided into the training group or the control group and performed exercise tests at 1 week, 3 weeks, 3 months, 6 months and 1 year after CABG. The HRV was measured, and the high-frequency component of HRV was used as an index of parasympathetic nerve activity (PNA); the plasma norepinephrine concentration (NE) was used as an index of sympathetic nervous activity. Cardiac output was also measured. In the training group, peak VO2, peak CO and PNA during exercise had improved at 3 weeks, but there was no improvement in these indices in the control group. NE decreased 1 week after CABG in both groups. These results indicate that physical training soon after CABG improves not only the exercise capacity, but also PNA.
-
7.
The effects of drugs used to treat obesity on the autonomic nervous system.
Hirsch, J, Mackintosh, RM, Aronne, LJ
Obesity research. 2000;(3):227-33
Abstract
OBJECTIVE Body fatness is partly under hypothalamic control with effector limbs, which include the endocrine system and the autonomic nervous system (ANS). In previous studies we have shown, in both obese and never-obese subjects, that weight increase leads to increased sympathetic and decreased parasympathetic activity, whereas weight decrease leads to decreased sympathetic and increased parasympathetic activity. We now report on the involvement of such ANS mechanisms in the action of anti-obesity drugs, independent of change in weight. RESEARCH METHODS AND PROCEDURES Normal weight males (ages 22 to 38 years) were fed a solid food diet, carefully measured to maintain body weight, for at least 2 weeks, as inpatients at the Rockefeller University General Clinical Research Center. In a single-blind, placebo/drug/placebo design, eight subjects received dexfenfluramine, seven phentermine (PHE), and seven sibutramine (SIB). ANS measures of parasympathetic and sympathetic activity included: determination of amount of parasympathetic control (PC) and sympathetic control (SC) of heart period (interbeat interval), using sequential pharmacological blockade by intravenous administration of atropine and esmolol. These autonomic controls of heart period are used to estimate the overall level of parasympathetic and sympathetic activities. Norepinephrine, dopamine, and epinephrine levels in 24-hour urine collections were measured and also resting metabolic rate (RMR). RESULTS Sufficient food intake maintained constant body weight in all groups. PHE and SIB produced significant increases in SC but no change in PC or in RMR. In contrast, dexfenfluramine produced marked decreases in SC, PC, and RMR. For all three drugs, the effects on urine catecholamines directly paralleled changes in cardiac measures of SC. DISCUSSION ANS responses to PHE and SIB were anticipated. The large, and unanticipated, response to dexfenfluramine suggests further study to determine whether there could be any relation of these ANS changes to the adverse cardiovascular effects of treatment with dexfenfluramine.