scholarly journals Effects of oral carbohydrate on autonomic nervous system counterregulatory responses during hyperinsulinemic hypoglycemia and euglycemia

2008 ◽  
Vol 295 (3) ◽  
pp. E618-E625 ◽  
Author(s):  
Andrew C. Ertl ◽  
Stephnie Mann ◽  
Antoinette Richardson ◽  
Vanessa J. Briscoe ◽  
Hannah B. Blair ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Pancreatic Polypeptide ◽  
Muscle Sympathetic Nerve Activity ◽  
Hyperinsulinemic Hypoglycemia ◽  
Autonomic Nervous ◽  
Healthy Humans ◽  
Neuroendocrine Responses ◽  
Blood Pressure Responses

The effects of oral carbohydrate on modulating counterregulatory responses in humans remain undecided. This study's specific aim was to determine the effects of oral carbohydrate on autonomic nervous system (ANS) and neuroendocrine responses during hyperinsulinemic hypoglycemia and euglycemia. Nineteen healthy volunteers were studied during paired, single blind experiments. Nine subjects underwent two-step glucose clamps consisting of 60 min of euglycemia (5.0 mmol/l) followed by either 15 g of oral carbohydrate (cal) as orange juice or a noncaloric control (nocal) and subsequent 90 min of clamped hypoglycemia (2.9 mmol/l). Ten other subjects underwent two randomized 150-min hyperinsulinemic-euglycemic clamps with cal or nocal control administered at 60 min. Oral carbohydrate initially blunted ( P < 0.05) epinephrine, norepinephrine, cortisol, glucagon, pancreatic polypeptide, muscle sympathetic nerve activity (MSNA), symptom, and systolic blood pressure responses during hypoglycemia. However, by the end of 90 min of hypoglycemia, plasma epinephrine and norepinephrine responses had rebounded and were increased ( P < 0.05) compared with control. MSNA and cortisol levels remained suppressed during hypoglycemia ( P < 0.05) after cal, whereas pancreatic polypeptide, glucagon, symptom, and blood pressure responses increased similar to control following initial suppression. Oral carbohydrate had no effects on neuroendocrine or ANS responses during hyperinsulinemic euglycemia. These results demonstrate that oral carbohydrate can have differential effects on the time course of ANS and neuroendocrine responses during hypoglycemia. We conclude that gastro-splanchnic-portal sensing of an amount of carbohydrate recommended for use in clinical practice for correction of hypoglycemia can have widespread and significant effects on central nervous system mediated counterregulatory responses in healthy humans.

Differential gender responses to hypoglycemia are due to alterations in CNS drive and not glycemic thresholds

2000 ◽  
Vol 279 (5) ◽  
pp. E1054-E1063 ◽  
Author(s):  
Stephen N. Davis ◽  
Chris Shavers ◽  
Fernando Costa
Keyword(s):  
Growth Hormone ◽  
Nervous System ◽  
Sexual Dimorphism ◽  
Pancreatic Polypeptide ◽  
Muscle Sympathetic Nerve Activity ◽  
Plasma Norepinephrine ◽  
Men And Women ◽  
Healthy Men ◽  
Neuroendocrine Responses ◽  
Blood Pressure Responses

The aims of this study were 1) to determine whether differential glycemic thresholds are the mechanism responsible for the sexual dimorphism present in neuroendocrine responses during hypoglycemia and 2) to define the differences in counterregulatory physiological responses that occur over a range of mild to moderate hypoglycemia in healthy men and women. Fifteen (8 male, 7 female) lean healthy adults underwent four separate randomized 2-h hyperinsulinemic (1.5 mU · kg−1· min−1) glucose clamp studies at euglycemia (90 mg/dl) or hypoglycemia of 70, 60, or 50 mg/dl. Plasma insulin levels were similar during euglycemic and hypoglycemic studies (91–96 ± 8 μU/ml) in men and women. Hypoglycemia of 70, 60, and 50 mg/dl all resulted in significant increases ( P < 0.05, P < 0.01) in epinephrine, glucagon, growth hormone, cortisol, and pancreatic polypeptide levels compared with euglycemic studies in men and women. Plasma norepinephrine levels were increased ( P < 0.05) only relative to euglycemic studies at a hypoglycemia of 50 mg/dl. Muscle sympathetic nerve activity (MSNA) increased significantly during hyperinsulinemic-euglycemic control studies. Further elevations of MSNA did not occur until hypoglycemia of 60 mg/dl in both men and women. Plasma epinephrine, glucagon, growth hormone, and pancreatic polypeptide were significantly increased in men compared with women during hypoglycemia of 70, 60, and 50 mg/dl. MSNA, heart rate, and systolic blood pressure responses were also significantly increased in men at hypoglycemia of 60 and 50 mg/dl. In summary, these studies have demonstrated that, in healthy men and women, the glycemic thresholds for activation of epinephrine, glucagon, growth hormone, cortisol, and pancreatic polypeptide occur between 70 and 79 mg/dl. Thresholds for activation of MSNA occur between 60 and 69 mg/dl, whereas norepinephrine is not activated until glycemia is between 50 and 59 mg/dl. We conclude that 1) differential glycemic thresholds are not the cause of the sexual dimorphism present in counterregulatory responses to hypoglycemia; 2) reduced central nervous system efferent input appears to be the mechanism responsible for lowered neuroendocrine responses to hypoglycemia in women; and 3) physiological counterregulatory responses (neuroendocrine, cardiovascular, and autonomic nervous system) are reduced across a broad range of hypoglycemia in healthy women compared with healthy men.

Electrical Stimulation of Acupuncture Points and Blood Pressure Responses to Postural Changes: A Pilot Study

2011 ◽  
Vol 20 (3) ◽  
pp. e67-e74 ◽  
Author(s):  
Alice Y. M. Jones ◽  
Y. L. Kwan ◽  
Nathan T. F. Leung ◽  
Rachel P. W. Yu ◽  
Cindy M. Y. Wu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Acupuncture Points ◽  
Large Artery ◽  
Postural Change ◽  
Autonomic Nervous ◽  
Postural Changes ◽  
Blood Pressure Responses

Background Application of transcutaneous electrical stimulation over acupuncture points (Acu-TENS) facilitates heart rate recovery after exercise and restores hemodynamic stability after open heart surgery. The role of Acu-TENS on cardiovascular parameters in response to postural changes has not been reported. Objective To investigate (1) the effect of Acu-TENS on blood pressure responses to −10º head-down postural change and (2) whether such effects were associated with modulation by the autonomic nervous system. Method Sixteen healthy volunteers, mean age 22.8 (SD, 3.1) years, were subjected to a −10º head-down tilt from the supine position on 3 separate occasions and received in random order the following 3 intervention protocols for 40 minutes before the postural change: Acu-TENS (over bilateral acupuncture points, PC6), sham-TENS (TENS applied to the skin over the patellae), and control (no electrical output from the TENS device applied at PC6). Mean arterial pressure, large artery elasticity index, cardiac output, and heart rate were recorded and compared at different stimulation protocols in the supine and −10º head-down tilt positions. Spectral analysis of heart rate variability was used to determine any modulation by the autonomic nervous system. Results Change in large artery elasticity index was observed only in the Acu-TENS group (P &lt; .05) and mean arterial pressure appeared most stable during Acu-TENS. Autonomic nervous system modulation was not apparent with spectral analysis, irrespective of intervention. Sympathetic activity predominated in all positions. Conclusion Acu-TENS seems to reduce blood pressure changes with −10º head-down tilt with concomitant changes in arterial vessel tone.

Risk assessment of occupational and occupationally conditioned diseases connection to noise when exceeding maximum permissible levels

2019 ◽  
pp. 17-19
Author(s):  
Vladimir A. Fokin ◽  
Dmitrii M. Shlyapnikov ◽  
Svetlana V. Red’ko
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
High Blood Pressure ◽  
Noise Exposure ◽  
Physical Factors ◽  
Autonomic Nervous ◽  
Permissible Levels ◽  
The Relationship ◽  
Perm Region

In accordance with the requirements of paragraph 3.2.6 of sanitary rules and norms «Sanitary and epidemiological requirements for physical factors at workplace», in the event of exceeding noise level at workplace above 80 dBA, an employer is obliged to assess the health risk of workers and confirm an acceptable risk to their health. The connection between the incidence of occupational and occupationally conditioned diseases with noise exposure exceeding the maximum permissible levels (80 dBA) was estimated. The assessment was carried out at a food industry enterprise of Perm Region. Assessing the relationship between morbidity and noise exposure is the first step in evaluation of occupational health risks for workers exposed to noise exceeding MAL. If a reliable relationship between morbidity and noise exposure is established, an assessment of occupational risk is conducted. The odds ratio (OR) for diseases characterized by high blood pressure and disorders of autonomic nervous system was <1 (confidence interval CI=0.11–1.61 and CI=0.08–2.78, respectively). The relative risk (RR) for diseases characterized by high blood pressure and disorders of autonomic nervous system was <1. The received data testify absence of connection of morbidity with exposure to industrial noise, calculation of etiological share of responses and levels of risk is not required.

Role of Autonomic Nervous System in Maintenance of Cerebral and Renal Hypertension

1957 ◽  
Vol 188 (2) ◽  
pp. 371-374 ◽  
Author(s):  
Sol Rothman ◽  
Douglas R. Drury
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Renal Hypertension ◽  
The Other ◽  
Peripheral Vasculature ◽  
Blood Pressures ◽  
Sympathetic Nervous ◽  
Blood Pressure Responses

The blood pressure responses to various drugs were investigated in renal hypertensive, cerebral hypertensive and normotensive rabbits. Hexamethonium bromide and Dibenamine reduced the blood pressures of renal and cerebral hypertensives. Effects in the normal were insignificant. The cerebral hypertensive's blood pressure was slightly affected by benzodioxane. Blood pressure was not reduced at all in the other groups. Blood pressure of the renal hypertensive rabbit was greatly reduced by Veriloid and dihydroergocornine. Blood pressures of cerebral and normal animals were affected to a lesser degree. The results suggest that maintenance of hypertension in the cerebral hypertensive rabbit depends on an overactive sympathetic nervous system, possibly due to the release of medullary pressor centers from inhibitory impulses originating in higher centers; whereas, the maintenance of hypertension in the renal hypertensive rabbit may be attributed to an increased reactivity of the peripheral vasculature to a normal sympathetic tone.

scholarly journals Patients with Impaired Descending Nociceptive Inhibitory System Present Altered Cardiac Vagal Control at Rest

2018 ◽  
Vol 1 (21;1) ◽  
pp. E409-E418
Author(s):  
Leandro Nogueira
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Musculoskeletal Pain ◽  
Blood Pressure Response ◽  
Pain Modulation ◽  
Pressure Response ◽  
Autonomic Modulation ◽  
Inhibitory System ◽  
Autonomic Nervous

Background: Patients with chronic musculoskeletal pain have a higher chance of presenting impairment in cardiovascular autonomic modulation, which may have implications for cardiovascular events. The autonomic nervous system plays an important role in pain modulation. However, it is unclear whether patients with inefficient descending nociceptive inhibition have poorer cardiovascular autonomic modulation. Objective: To compare the cardiovascular autonomic modulation of patients with musculoskeletal pain who had normal versus impaired functioning of descending nociceptive inhibitory system (DNIS). Study Design: A cross-sectional study. Setting: Physiotherapy outpatient service. Methods: Fifty-six patients with musculoskeletal pain were included. Conditioned pain modulation was assessed by the difference of algometric values held in the dorsal forearm and tibialis anterior muscle, before and after a thermal pain stimulus was employed via the cold pressure test (CPT). Patients with inefficient DNIS in both sites were classified as impaired responders (n = 14). The others were classified as normal responders (n = 42). Cardiac autonomic modulation was monitored at rest by heart rate variability (HRV). The blood pressure response to the CPT was used as a proxy of sympathetic responsiveness. Results: Most of the patients were women (60%) and had chronic pain (75%). The groups had similar demographic characteristics. Patients with impaired DNIS showed lower HRV [RMSSD (P = 0.020), SDRR (P = 0.009), HF (ms2 ) (P = 0.027), LF (ms2 ) (P = 0.004), and total power (P = 0.002)]. The blood pressure response to CPT was similar between groups (systolic pressure, P = 0.813; diastolic pressure, P = 0.709). Limitation: Physical activity level, emotional changes, and visceral pathologies can alter the autonomic nervous system and may represent potential confounders. The low number of patients may have biased the results. Conclusion: Patients with impaired DNIS presented lower resting HRV, indicating an altered vagal control of the heart. In contrast, the blood pressure response to a sympathoexcitatory stimulus was preserved. The study was approved by the Research Ethics Committee of Augusto Motta University Centre (CAAE number: 46245215.9.0000.5235), and all patients signed the Informed Consent Form. Key words: Musculoskeletal pain, autonomic nervous system, heart rate, chronic pain, diffuse noxious inhibitory control, blood pressure, sympathetic nervous system, parasympathetic nervous system

Heart Rate and Blood Pressure Changes During Autonomic Nervous System Challenge in Panic Disorder Patients

2010 ◽  
Vol 72 (5) ◽  
pp. 442-449 ◽  
Author(s):  
Jose M. Martinez ◽  
Amir Garakani ◽  
Horacio Kaufmann ◽  
Cindy J. Aaronson ◽  
Jack M. Gorman
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Panic Disorder ◽  
Autonomic Nervous ◽  
Pressure Changes

Effect of Variation of Blood Pressure on the Autonomic Nervous System

1940 ◽  
Vol 43 (2) ◽  
pp. 236-240 ◽  
Author(s):  
E. Gellhorx ◽  
C. W. Darrow ◽  
L. Yesinick
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Autonomic Nervous

Abstract P129: Role of the Autonomic Nervous System in Remote Postconditioning in Humans

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Rupert P Williams ◽  
Michael I Okorie ◽  
Harminder Gill ◽  
John E Deanfield ◽  
Raymond J MacAllister ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Whole Body ◽  
Limb Ischaemia ◽  
Protective Effects ◽  
Blood Pressure Cuff ◽  
Autonomic Nervous ◽  
Pressure Cuff ◽  
Remote Postconditioning

Brief periods of ischaemia activate systemic mechanisms that induce whole-body tolerance to subsequent prolonged and injurious ischaemia. This phenomenon, remote ischaemic preconditioning (RIPC), is sufficiently acute to reduce ischaemia-reperfusion (IR) injury even when applied simultaneously with injurious ischaemia. This aspect of RIPC is termed remote postconditioning (RPostC). We have previously demonstrated a role for the autonomic nervous system in RIPC. Using an in vivo model of endothelial IR injury, we determined if RPostC is dependent on adrenergic autonomic mechanisms. Vascular ultrasound was used to assess endothelial function in healthy volunteers by measuring dilatation of the brachial artery in response to increased blood flow during reactive hyperaemia (flow-mediated dilatation; FMD). Endothelial IR injury was induced by 20 min of upper limb ischaemia (inflation of a blood pressure cuff to 200 mm Hg) followed by reperfusion. RPostC was induced by applying 2 cycles of 5 minutes ischaemia and 5 minutes reperfusion on the leg during arm ischaemia (via a second blood pressure cuff). In order to determine the dependence of RPostC on autonomic activation, we administered the alpha adrenoceptor blocker phentolamine (0.2– 0.7mg/min, intravenously) during the application of the RPostC stimulus. FMD was determined before ischaemia and at 20 minutes of reperfusion. FMD (percentage change from baseline diameter) was compared statistically by ANOVA. IR alone caused a significant reduction in FMD (5.9±0.7% pre- versus 2.2±0.4% post-IR, n=9, P<0.001). This reduction was prevented by RPostC (5.8±0.4% pre- versus 5.4±0.3% post-IR, n=8, P>0.05). Systemic phentolamine blocked the protective effects of RPostC (FMD 6.1±0.5% pre- versus 2.0±0.3% post-IR, n=7, P<0.001). These data indicate, for the first time in humans, that protection from RPostC depends on preservation of adrenergic signalling. Alpha blockade neutralises one of the endogenous mechanisms of ischemic protection in humans; the clinical consequences of this remain to be determined.

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