Sympathetic nerve activity in metabolic control – some basic concepts

Fagius, Jan

doi:10.1046/j.1365-201x.2003.01086.x

Cited by 71 publications

(59 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We observed modest but significant increases in resting heart rates and blood pressures and modest increases in LV mass, but not LV/body weight ratios, seen in association with increased plasma norepinephrine and cardiac norepinephrine spillover. There is an extensive literature linking chronic hyperinsulinemia associated with whole body insulin resistance to increased sympathetic nervous system activation (5,7,30), leading to hypertension. In this regard, there was significant impairment in isovolumic relaxation time, LV stroke work, and external mechanical efficiency.…”

Section: Discussionmentioning

confidence: 99%

Aging is associated with myocardial insulin resistance and mitochondrial dysfunction

Bhashyam

Parikh²,

Bolukoglu³

et al. 2007

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

Aging is associated with insulin resistance, often attributable to obesity and inactivity. Recent evidence suggests that skeletal muscle insulin resistance in aging is associated with mitochondrial alterations. Whether this is true of the senescent myocardium is unknown. Twelve young (Y, 4 years old) and 12 old (O, 11 years old) dogs, matched for body mass, were instrumented with left-ventricular pressure gauges, aortic and coronary sinus catheters, and flow probes on left circumflex artery. Before surgery, all dogs participated in a 6-wk exercise program. Dogs underwent measurements of hemodynamics and plasma substrates before and during a 2-h hyperinsulinemic-euglycemic clamp to measure whole body and myocardial glucose and nonesterified fatty acid uptake. Following the protocol, myocardial and skeletal samples were obtained to measure components of the insulin-signaling cascade and mitochondrial structure. There was no difference in plasma glucose (Y, 90 Ϯ 4 mg/dl; O, 87 Ϯ 4 mg/dl), but old dogs had higher (P Ͻ 0.02) nonesterified fatty acids (Y, 384 Ϯ 48 mol/l; O, 952 Ϯ 97 mol/l) and plasma insulin (Y, 39 Ϯ 11 pmol/l; O, 108 Ϯ 18 pmol/l). Old dogs had impaired total body glucose disposition (Y, 11.5 Ϯ 1 mg⅐ kgThe impaired insulin action was associated with altered insulin signaling and glucose transporter (GLUT4) translocation. There were myocardial mitochondrial structural changes observed in association with decreased expression of uncoupling protein-3. Aging is associated with both whole body and myocardial insulin resistance, independent of obesity and inactivity, but involving altered mitochondrial structure and impaired cellular insulin action. myocardium; mitochondria; uncoupling protein-3 ADVANCED AGE IS ASSOCIATED with the development of whole body insulin resistance and increased incidence of type 2 diabetes in humans (4,9,14,33). Aging is also frequently accompanied by obesity and inactivity that predispose to the development of insulin resistance (6,16,17,32,39). However, it is unclear what independent role aging plays in the pathogenesis of insulin resistance in the absence of obesity and inactivity. Furthermore, it is unclear as to whether these abnormalities in insulin action extend to the senescent myocardium, where continuous contractile function makes inactivity less relevant.Recently, skeletal muscle insulin resistance in both advanced age (1, 28) and in lean offspring of patients with type 2 diabetes (10, 22, 29) was associated with altered mitochondrial protein expression (28) and density (10). These abnormalities were seen in association with increased intracellular lipid accumulation (22,28,29). However, it is unknown whether these same alterations are evident in the senescent myocardium, whether they are associated with altered insulin action, and whether they predispose to altered left ventricle (LV) hemodynamics in the absence of hyperglycemia or other conventional risk factors.Accordingly, the purpose of the present study was to determine whether aging alone was associated with bot...

show abstract

Section: Discussionmentioning

confidence: 99%

Aging is associated with myocardial insulin resistance and mitochondrial dysfunction

Bhashyam

Parikh²,

Bolukoglu³

et al. 2007

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

show abstract

“…Sympathetic (SNS) and parasympathetic nervous system (PNS) support the distinct and opposite functions in the alertness and physiology. In humans, within the relation to a hunger-satiety shift, changes of the SNS and PNS activity can occur before nutritional hormone levels are secreted, as demonstrated by the instant changes in the states of alertness (16-18), muscle sympathetic nerve activity (19), and cardiac output (20), which may be part of cephalic phase responses (21) after food intake. An inverse relationship of SNS activity and body fat, which suggests a role of β-adrenergic receptors in peripheral and central control of eating, emphasizes the importance of the SNS in food intake (22).…”

Section: Discussionmentioning

confidence: 99%

The effects of Ramadan fasting on heart rate variability in healthy individuals: A prospective study

Cansel

Taşolar

Yağmur³

et al. 2014

Anadolu Kardiyol Derg

View full text Add to dashboard Cite

Objective: Ramadan fasting is one of the five fundamental rituals of Islam. Heart rate variability (HRV) is an independent predictor of increased mortality of patients with myocardial infarction and congestive heart failure. Although many patients in this region fast once a year, the effects of fasting on the HRV, which has a prognostic significance for patients with myocardial infarction and congestive heart failure, are not known. Therefore, the study on the effects of one month fast of HRV in healthy volunteers seems to be reasonable to address. Methods: Our study is a prospective cohort study that includes a total of 40 healthy volunteers with sinus rhythm between 19 and 40 years of age (16 female and 24 male). HRV was determined twice by ambulatory 24-hour Holter recordings at fasting in the middle of Ramadan and first week after Ramadan month. Mean values of continuous variables were compared by using the Student t-test or Mann-Whitney U test. Paired t-test or Wilcoxon test were used for comparison of variables between groups. Results: When two groups compared, statistically significant differences were found in terms of RR (p=0.049), SDNNI (p=0.010), rMSSD (p=0.009), pNN50 (p=0.015), T power (p=0.009), LF (p=0.008), Lfnu (p=0.002), HF (p=0.022) and Hfnu (p=0.013) values. Conclusion: In our study, HRV parameters were found to be increased in Ramadan month, so we think that Ramadan fasting enhances the activity of the parasympathetic system. (Anadolu Kardiyol Derg 2014; 14: 413-6)

show abstract

“…Despite few studies in healthy humans showing a possible increase (55) or decrease (23) in MSNA, there is no convincing evidence that exercise alters resting MSNA. Heart failure and type 2 diabetes are associated with high sympathetic nerve activity (13). Conversely, exercise has been shown to reduce MSNA in heart failure (16) and to improve HRV in type 2 diabetes (83).…”

mentioning

confidence: 99%

Low-frequency electroacupuncture and physical exercise decrease high muscle sympathetic nerve activity in polycystic ovary syndrome

Stener-Victorin¹,

Jedel²,

Janson³

et al. 2009

American Journal of Physiology-Regulatory, Integrative and Comp

147

166

View full text Add to dashboard Cite

Stener-Victorin E, Jedel E, Janson PO, Sverrisdottir YB. Lowfrequency electroacupuncture and physical exercise decrease high muscle sympathetic nerve activity in polycystic ovary syndrome. Am J Physiol Regul Integr Comp Physiol 297: R387-R395, 2009. First published June 3, 2009 doi:10.1152/ajpregu.00197.2009We have recently shown that polycystic ovary syndrome (PCOS) is associated with high muscle sympathetic nerve activity (MSNA). Animal studies support the concept that low-frequency electroacupuncture (EA) and physical exercise, via stimulation of ergoreceptors and somatic afferents in the muscles, may modulate the activity of the sympathetic nervous system. The aim of the present study was to investigate the effect of these interventions on sympathetic nerve activity in women with PCOS. In a randomized controlled trial, 20 women with PCOS were randomly allocated to one of three groups: low-frequency EA (n ϭ 9), physical exercise (n ϭ 5), or untreated control (n ϭ 6) during 16 wk. Direct recordings of multiunit efferent postganglionic MSNA in a muscle fascicle of the peroneal nerve before and following 16 wk of treatment. Biometric, hemodynamic, endocrine, and metabolic parameters were measured. Low-frequency EA (P ϭ 0.036) and physical exercise (P ϭ 0.030) decreased MSNA burst frequency compared with the untreated control group. The low-frequency EA group reduced sagittal diameter (P ϭ 0.001), while the physical exercise group reduced body weight (P ϭ 0.004) and body mass index (P ϭ 0.004) compared with the untreated control group. Sagittal diameter was related to MSNA burst frequency (Rs ϭ 0.58, P Ͻ 0.005) in the EA group. No correlation was found for body mass index and MSNA in the exercise group. There were no differences between the groups in hemodynamic, endocrine, and metabolic variables. For the first time we demonstrate that low-frequency EA and physical exercise lowers high sympathetic nerve activity in women with PCOS. Thus, treatment with low-frequency EA or physical exercise with the aim to reduce MSNA may be of importance for women with PCOS. polycystic ovary syndrome; sympathetic nerve activity; testosterone; insulin resistance; metabolic syndrome; cardiovascular disease POLYCYSTIC OVARY SYNDROME (PCOS) is one of the most common female endocrine disorders affecting ϳ10% of women of reproductive age, and is strongly associated with hyperandrogenism and ovulatory dysfunction (8,46). PCOS increases the risk of metabolic disturbances such as abdominal obesity, hyperinsulinaemia, and insulin resistance, which can lead to type 2 diabetes, and dyslipidemia (8, 46), as well as hypertension which may lead to the development of other cardiovascular diseases (35).Despite extensive research, the primary etiology remains unknown, although both environmental and genetic factors are implicated (17). Existing evidence suggests the ovarian theca cells, the major source of androgen production and secretion (22) to play a key role in the etiology. Also, the hypothalamicpituitary axis (50) and defective insulin a...

show abstract

Sympathetic nerve activity in metabolic control – some basic concepts

Cited by 71 publications

References 64 publications

Aging is associated with myocardial insulin resistance and mitochondrial dysfunction

Aging is associated with myocardial insulin resistance and mitochondrial dysfunction

The effects of Ramadan fasting on heart rate variability in healthy individuals: A prospective study

Low-frequency electroacupuncture and physical exercise decrease high muscle sympathetic nerve activity in polycystic ovary syndrome

Contact Info

Product

Resources

About