The Role of the Autonomic Nervous System in the Pathophysiology of Obesity

Intestinal gluconeogenesis: A translator of nutritional information needed for glycemic and emotional balance

At the interface between the outside world and the self, the intestine is the first organ receiving nutritional information. One intestinal function, gluconeogenesis, is activated by various nutrients, particularly diets enriched in fiber or protein, and thus results in glucose production in the portal vein in the post-absorptive period. The detection of portal glucose induces a nervous signal controlling the activity of the central nuclei involved in the regulation of metabolism and emotional behavior. Induction of intestinal gluconeogenesis is necessary for the beneficial effects of fiber or protein-enriched diets on metabolism and emotional behavior. Through its ability to translate nutritional information from the diet to the brain's regulatory centers, intestinal gluconeogenesis plays an essential role in maintaining physiological balance.

Metabolic flexibility and resting autonomic function in active menopausal women

PURPOSE

The present study aims to analyze the relationship between cardiac autonomic control at rest-i.e., baseline Heart Rate Variability (HRV)-and metabolic flexibility assessed by means of the FATox and CHOox oxidation rates at the intensities of maximum fat and carbohydrate oxidation (MFO and MCO, respectively).

METHODS

Twenty-four active over-60 women (66.8 ± 4.4 years) had their HRV assessed with 10 min recordings under resting conditions, and this was analyzed with Kubios Scientific software. After this, an incremental submaximal cycling test, starting at 30 watts, with increments of 10 watts every 3 min 15 s was performed. FATox and CHOox were calculated in the last 60 s at each step, using Frayn's equation. MFO and MCO were further obtained.

RESULTS

Nonlinear SampEn and 1-DFAα1 (Detrending Fluctuation Analysis score) at rest were both moderate and significantly (p < 0.05) related to FATox (r = 0.43, r = -0.40) and CHOox (r = -0.59, r = 0.41), as well as RER (r = -0.43, r = 0.43) at FATmax intensity. At the MCO intensity, no association was observed between HRV and oxidation rates. However, DFAα1 (r = -0.63, p < 0.05), the frequency ratio LF/HF (r = -0.63, p < 0.05), and the Poincaré ratio SD1/SD2 (r = 0.48, p < 0.05) were correlated with blood lactate concentration.

CONCLUSION

These results support the autonomic resources hypothesis, suggesting that better autonomic function at rest is related to enhanced metabolic flexibility in postmenopausal women. They also underpin a comprehensive analysis of cardiovascular-autonomic health with aging. The results imply that non-linear DFAα1 and SampEn are appropriate to analyze this association in health of the aging cardiovascular-autonomic system.

Non-Hereditary Obesity Type Networks and New Drug Targets: An In Silico Approach

Obesity, a chronic, preventable disease, has significant comorbidities that are associated with a great human and financial cost for society. The aim of the present work is to reconstruct the interactomes of non-hereditary obesity to highlight recent advances of its pathogenesis, and discover potential therapeutic targets. Obesity and biological-clock-related genes and/or gene products were extracted from the biomedical literature databases PubMed, GeneCards and OMIM. Their interactions were investigated using STRING v11.0 (a database of known and predicted physical and indirect associations among genes/proteins), and a high confidence interaction score of >0.7 was set. We also applied virtual screening to discover natural compounds targeting obesity- and circadian-clock-associated proteins. Two updated and comprehensive interactomes, the (a) stress- and (b) inflammation-induced obesidomes involving 85 and 93 gene/gene products of known and/or predicted interactions with an average node degree of 9.41 and 10.8, respectively, were produced. Moreover, 15 of these were common between the two non-hereditary entities, namely, ADIPOQ, ADRB2/3, CCK, CRH, CXCL8, FOS, GCG, GNRH1, IGF1, INS, LEP, MC4R, NPY and POMC, while phelligridin E, a natural product, may function as a potent FOX1-DBD interaction blocker. Molecular networks may contribute to the understanding of the integrated regulation of energy balance/obesity pathogenesis and may associate chronopharmacology schemes with natural products.

Genetic markers of cardiac autonomic neuropathy in the Kazakh population

BACKGROUND

Cardiac autonomic neuropathy (CAN) is a complication of diabetes mellitus (DM) that increases the risk of morbidity and mortality by disrupting cardiac innervation. Recent evidence suggests that CAN may manifest even before the onset of DM, with prediabetes and metabolic syndrome potentially serving as precursors. This study aims to identify genetic markers associated with CAN development in the Kazakh population by investigating the SNPs of specific genes.

MATERIALS AND METHODS

A case-control study involved 82 patients with CAN (cases) and 100 patients without CAN (controls). A total of 182 individuals of Kazakh nationality were enrolled from a hospital affiliated with the RSE "Medical Center Hospital of the President's Affairs Administration of the Republic of Kazakhstan". 7 SNPs of genes FTO, PPARG, SNCA, XRCC1, FLACC1/CASP8 were studied. Statistical analysis was performed using Chi-square methods, calculation of odds ratios (OR) with 95% confidence intervals (CI), and logistic regression in SPSS 26.0.

RESULTS

Among the SNCA gene polymorphisms, rs2737029 was significantly associated with CAN, almost doubling the risk of CAN (OR 2.03(1.09-3.77), p = 0.03). However, no statistically significant association with CAN was detected with the rs2736990 of the SNCA gene (OR 1.00 CI (0.63-1.59), p = 0.99). rs12149832 of the FTO gene increased the risk of CAN threefold (OR 3.22(1.04-9.95), p = 0.04), while rs1801282 of the PPARG gene and rs13016963 of the FLACC1 gene increased the risk twofold (OR 2.56(1.19-5.49), p = 0.02) and (OR 2.34(1.00-5.46), p = 0.05) respectively. rs1108775 and rs1799782 of the XRCC1 gene were associated with reduced chances of developing CAN both before and after adjustment (OR 0.24, CI (0.09-0.68), p = 0.007, and OR 0.43, CI (0.22-0.84), p = 0.02, respectively).

CONCLUSION

The study suggests that rs2737029 (SNCA gene), rs12149832 (FTO gene), rs1801282 (PPARG gene), and rs13016963 (FLACC1 gene) may be predisposing factors for CAN development. Additionally, SNPs rs1108775 and rs1799782 (XRCC1 gene) may confer resistance to CAN. Only one polymorphism rs2736990 of the SNCA gene was not associated with CAN.

Effect of Transcutaneous Electrical Nerve Stimulation of T6 Dermatome on Appetite and Weight Reduction in Obese Individuals: A Pilot Study

BACKGROUND

Previous work demonstrated the beneficial effect of T6 dermatomal stimulation by the percutaneous method in managing obesity. However, a simple, cost-effective, and feasible intervention stimulating the dermatome can be a potential solution for obesity care.

OBJECTIVE

The objective of this study was to find the effect of transcutaneous electrical nerve stimulation (TENS) of T6 dermatome on appetite and weight loss in obese individuals.

MATERIAL AND METHODS

In this prospective single-arm experimental study, 20 obese patients received TENS treatment of T6 dermatome for 30 min, once a week and for 12 weeks. Outcome measures such as appetite level in the visual analog scale (VAS), weight in kg, and basal metabolic index (BMI) in kg/m2 were assessed at baseline, 12 weeks -post-intervention, and at 8 weeks of follow-up.

RESULTS

A statistically significant difference in all the variables was found from baseline to 12 weeks of intervention (P < 0.001) and maintained till 8 weeks of follow-up. From pre- to post-treatment, the effect size for appetite reduction was large (>1) while for weight and BMI loss was (0.14, 0.16), respectively small. Additionally, a weak correlation was found between pre- and follow-up appetite and weight loss (r = 0.25, P = 0.294).

CONCLUSIONS

Twelve weeks of TENS treatment of T6 dermatome showed a positive effect in reducing appetite with sustained reduction up to 8 weeks of follow-up even after completion of the intervention. However, in the absence of dietary modification, TENS treatment was associated with low effect sizes weight and BMI loss.

Cardiorespiratory fitness is linked with heart rate variability during stress in "at-risk" adults

BACKGROUND

Physiological mechanisms explaining why cardiorespiratory fitness (CRF) predicts cardiovascular morbidity and mortality are incompletely understood. We examined if CRF modifies vagally mediated heart rate variability (HRV) during acute physical or psychosocial stress or night-time sleep in adults with cardiovascular risk factors.

METHODS

Seventy-eight adults (age 56 years [IQR 50-60], 74% female, body mass index 28 kg/m2 [IQR 25-31]) with frequent cardiovascular risk factors participated in this cross-sectional study. They went through physical (treadmill cardiopulmonary exercise test [CPET]) and psychosocial (Trier Social Stress Test for Groups [TSST-G]) stress tests and night-time sleep monitoring (polysomnography). Heart rate (HR) and vagally mediated HRV (root mean square of successive differences between normal R-R intervals [RMSSD]) were recorded during the experiments and analyzed by taking account of potential confounders.

RESULTS

CRF (peak O2 uptake) averaged 99% (range 78-126) in relation to reference data. From pre-rest to moderate intensities during CPET and throughout TSST-G, HR did not differ between participants with CRF below median (CRFlower) and CRF equal to or above median (CRFhigher), whereas CRFhigher had higher HRV than CRFlower, and CRF correlated positively with HRV in all participants. Meanwhile, CRF had no independent associations with HR or HRV levels during slow-wave sleep, the presence of metabolic syndrome was not associated with recorded HR or HRV levels, and single factors predicted HRV responsiveness independently only to limited extents.

CONCLUSIONS

CRF is positively associated with prevailing vagally mediated HRV at everyday levels of physical and psychosocial stress in adults with cardiovascular risk factors.

Prevalence and predictors of preoperative cardiac autonomic dysfunction among elective neurosurgical patients: A prospective observational study

Background and Aims

The autonomic nervous system (ANS) is cardinal for systemic homeostasis. Autonomic dysfunction is prevalent in as high as 65% of patients presenting for cardiac surgery in the Indian scenario. Pre-existing cardiac autonomic dysfunction (CAD) in surgical patients can accentuate perioperative haemodynamic fluctuations during stressful intraoperative events, predispose to adverse cardiac events, and contribute to morbidity and mortality. The prevalence and predictors of CAD in the elective neurosurgical population are unknown in the Indian scenario. The current study was conducted to bridge this knowledge gap.

Methods

In this single-centre prospective observational study conducted at a tertiary care neurosciences centre, among 400 consenting adult patients of either gender, between 18 and 80 years of age, undergoing elective neurosurgery, the preoperative ANS function at the bedside was assessed as the primary outcome measure. The ANS status was evaluated using ANSiscope™-derived indices of heart rate variability. The diagnosis of CAD was made when the ANS index exceeded a threshold of 13.5. Data regarding predictors of CAD were collected from patient records as the secondary outcome measure. Statistical analysis was done using the R software. A P-value of <0.05 was considered statistically significant.

Results

The prevalence of preoperative CAD in our study population was 79.7% (319/400 patients). None of the demographic and baseline clinical characteristics we studied predicted CAD in our study.

Conclusion

We observed a significant prevalence of preoperative CAD among elective neurosurgical patients. None of the parameters we evaluated predicted CAD in our study.

Autonomic Function in Obese Children and Adolescents: Systematic Review and Meta-Analysis

Background: Obesity is invariably accompanied by autonomic dysfunction, although data in pediatric populations are conflicting. Methods: We conducted a systematic review and meta-analysis of 12 studies (totaling 1102 participants) comparing obese and normal-weight subjects (5-18 years of age), defined as body mass index >95th or <85th percentile, respectively. Using a random-effects model, we report the standardized mean differences (SMD) of sympathetic and vagal indices of heart rate variability. Results: Autonomic dysfunction was present in the obesity group, based on the average SMD in the standard deviation of sinus intervals (at -0.5340), and on the ratio of low (LF)- to high (HF)-frequency spectra (at 0.5735). There was no difference in sympathetic activity, but the heterogeneity among the relevant studies weakens this result. SMD in HF (at 0.5876), in the root mean square of successive differences between intervals (at -0.6333), and in the number of times successive intervals exceeded 50 ms divided by the total number of intervals (at -0.5867) indicated lower vagal activity in the obesity group. Conclusions: Autonomic dysfunction is present in obese children and adolescents, attributed to lower vagal activity. Further studies are needed in various pediatric cohorts, placing emphasis on sympathetic activity.

Correlative relationship between body mass index and heart rate variability in psychiatric disorders

OBJECTIVE

Indicators of heart rate variability (HRV) have been used to assess the autonomic activity. However, the influence of obesity on HRV in these patients remains to be determined. This study aimed to examine how obesity (measured with the body mass index [BMI]) affects HRV and determine whether the effect varies among different psychiatric disorders. We recruited 3159 consecutive patients, including 1744 with schizophrenia, 966 with mood disorders, and 449 with anxiety disorders. Patients were divided into four groups based on BMI: underweight (< 18.5), normal weight (18.5-23.9), overweight (24-27.9), and obese (≥ 28). The cardiovascular status was assessed using several time- and frequency-based HRV indicators, measured via electrocardiogram signals recorded for 5 min. The mean BMI of the participants was 23.6 ± 4.0. The patients in the overweight and obese groups were 29.4% and 13.6% of the total, respectively. The HRV indicators were higher in underweight and normal-weight patients than in the overweight and obese ones. After stratification based on the psychiatric diagnosis, the patients with mood disorders showed lower HRV than those with schizophrenia or anxiety disorder in the normal-weight group. In contrast, in the overweight and obese groups the patients with mood disorders showed higher HRV than those with the other disorders. The HRV variables were significantly associated with BMI, and higher BMI was associated with higher heart rates and lower HRV. These results indicate that weight gain in psychiatric disorders is associated with an imbalance in autonomic nerve activity. However, the relationship between autonomic activity, weight gain, and psychiatric disorders warrants further investigation.

The role of the gastrointestinal barrier in obesity-associated systemic inflammation

Systemic inflammation is a key contributor to the onset and progression of several obesity-associated diseases and is thought to predominantly arise from the hyperplasia and hypertrophy of white adipose tissue. However, a growing body of works suggests that early changes in the gastrointestinal (GI) barrier may contribute to both local, within the GI lining, and systemic inflammation in obesity. Intestinal barrier dysfunction is well-characterized in inflammatory GI disorders such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) and is known to contribute to systemic inflammation. Thus, drawing parallels between GI disorders, where intestinal permeability and systemic inflammation are prominent features, and obesity-induced GI manifestations may provide insights into the potential role of the intestinal barrier in systemic inflammation in obesity. This review summarizes the current literature surrounding intestinal barrier dysfunction in obesity and explores the potential role of intestinal hyperpermeability and intestinal barrier dysfunction in the development of systemic inflammation and GI dysfunction in obesity.

Carotid body denervation improves hyperglycemia in obese mice

The carotid bodies (CBs) have been implicated in glucose abnormalities in obesity via elevation of activity of the sympathetic nervous system. Obesity-induced hypertension is mediated by insulin receptor (INSR) signaling and by leptin, which binds to the leptin receptor (LEPRb) in CB and activates transient receptor potential channel subfamily M member 7 (TRPM7). We hypothesize that in mice with diet-induced obesity, hyperglycemia, glucose intolerance, and insulin resistance will be attenuated by the CB denervation (carotid sinus nerve dissection, CSND) and by knockdown of Leprb, Trpm7, and Insr gene expression in CB. In series of experiments in 75 male diet-induced obese (DIO) mice, we performed either CSND (vs. sham) surgeries or shRNA-induced suppression of Leprb, Trpm7, or Insr gene expression in CB, followed by blood pressure telemetry, intraperitoneal glucose tolerance and insulin tolerance tests, and measurements of fasting plasma insulin, leptin, corticosterone, glucagon and free fatty acids (FFAs) levels, hepatic expression of gluconeogenesis enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G-6-Pase) mRNA and liver glycogen levels. CSND decreased blood pressure, fasting blood glucose levels and improved glucose tolerance without any effect on insulin resistance. CSND did not affect any hormone levels and gluconeogenesis enzymes, but increased liver glycogen level. Genetic knockdown of CB Leprb, Trpm7, and Insr had no effect on glucose metabolism. We conclude that CB contributes to hyperglycemia of obesity, probably by modulation of the glycogen-glucose equilibrium. Diabetogenic effects of obesity on CB in mice do not occur via activation of CB Leprb, Trpm7, and Insr.NEW & NOTEWORTHY This paper provides first evidence that carotid body denervation abolishes hypertension and improves fasting blood glucose levels and glucose tolerance in mice with diet-induced obesity. Furthermore, we have shown that this phenomenon is associated with increased liver glycogen content, whereas insulin sensitivity and enzymes of gluconeogenesis were not affected.

The role of the autonomic nervous system in polycystic ovary syndrome

This article reviewed the relationship between the autonomic nervous system and the development of polycystic ovary syndrome (PCOS). PCOS is the most common reproductive endocrine disorder among women of reproductive age. Its primary characteristics include persistent anovulation, hyperandrogenism, and polycystic ovarian morphology, often accompanied by disturbances in glucose and lipid metabolism. The body's functions are regulated by the autonomic nervous system, which consists mainly of the sympathetic and parasympathetic nervous systems. The autonomic nervous system helps maintain homeostasis in the body. Research indicates that ovarian function in mammals is under autonomic neural control. The ovaries receive central nervous system information through the ovarian plexus nerves and the superior ovarian nerves. Neurotransmitters mediate neural function, with acetylcholine and norepinephrine being the predominant autonomic neurotransmitters. They influence the secretion of ovarian steroids and follicular development. In animal experiments, estrogen, androgens, and stress-induced rat models have been used to explore the relationship between PCOS and the autonomic nervous system. Results have shown that the activation of the autonomic nervous system contributes to the development of PCOS in rat. In clinical practice, assessments of autonomic nervous system function in PCOS patients have been gradually employed. These assessments include heart rate variability testing, measurement of muscle sympathetic nerve activity, skin sympathetic response testing, and post-exercise heart rate recovery evaluation. PCOS patients exhibit autonomic nervous system dysfunction, characterized by increased sympathetic nervous system activity and decreased vagal nerve activity. Abnormal metabolic indicators in PCOS women can also impact autonomic nervous system activity. Clinical studies have shown that various effective methods for managing PCOS regulate patients' autonomic nervous system activity during the treatment process. This suggests that improving autonomic nervous system activity may be an effective approach in treating PCOS.

Predictors of Cardiac Autonomic Dysfunction in Obesity-Related Hypertension

INTRODUCTION

Cardiac Autonomic Dysfunction (CAD) is an overlooked cardiovascular risk factor in individuals with obesity-related hypertension. Despite its clinical significance, there is a notable lack of clarity regarding the pathophysiological correlates involved in its onset and progression.

AIM

The present study aimed to identify potential predictors of CAD in obesity-related hypertension.

METHODS

A total of 72 participants (34 men and 38 women) were enrolled. Comprehensive evaluations were conducted, including cardiac autonomic function assessments, body composition estimation and biochemical analysis. Participants were categorized as CAD-positive or CAD-negative based on Ewing's criteria for autonomic dysfunction. Univariate logistic regression analysis was performed to identify potential predictors for CAD. Multivariate logistic regression models were further constructed by adjusting clinically relevant covariates to identify independent predictors of CAD.

RESULTS

Multivariate logistic regression analysis revealed that resting heart rate (HRrest), (odds ratio, confidence interval: 0.85, 0.78-0.93; p = 0.001) and percentage body fat (BF%), (odds ratio, confidence interval: 0.78, 0.64-0.96; p = 0.018) were significant independent predictors of CAD. Receiver Operating Characteristic curve analysis depicted optimal cut-off values for HRrest and BF% as > 74.1 bpm and > 33.6%, respectively. Multicolinearity analysis showed variance inflation factors (VIF) below the cautionary threshold of 3.

CONCLUSIONS

The HRrest and BF% emerged as significant independent predictors of CAD in obesity-related hypertension. Therapeutic strategies should target HRrest < 74.1 bpm and BF% < 33.6% to mitigate CAD risk in this population. Future trials are required to establish causal relationships and may consider additional confounding variables in obesity-related hypertension.

Elevated transaminases in congenital central hypoventilation syndrome

Patients with CCHS who also have Hirschsprung disease, elevated or low BMI, or pulmonary hypertension may be predisposed to elevated transaminases and may need periodic follow-up of their hepatic function https://bit.ly/3uW7AUG.

Morbid obesity influences the nocturnal electrocardiogram wave and interval durations among suspected sleep apnea patients

BACKGROUND

Obesity is a global issue with a major impact on cardiovascular health. This study explores how obesity influences nocturnal cardiac electrophysiology in suspected obstructive sleep apnea (OSA) patients.

METHODS

We randomly selected 12 patients from each of the five World Health Organization body mass index (BMI) classifications groups (ntotal  = 60) while keeping the group's age and sex matched. We evaluated 1965 nocturnal electrocardiography (ECG) samples (10 s) using modified lead II recorded during normal saturation conditions. R-wave peaks were detected and confirmed using dedicated software, with the exclusion of ventricular extrasystoles and artifacts. The duration of waves and intervals was manually marked. The average electric potential graphs were computed for each segment. Thresholds for abnormal ECG waveforms were P-wave > 120 ms, PQ interval > 200 ms, QRS complex > 120 ms for, and QTc > 440 ms.

RESULTS

Obesity was significantly (p < .05) associated with prolonged conduction times. Compared to the normal weight (18.5 ≤ BMI < 25) group, the morbidly obese patients (BMI ≥ 40) had a significantly longer P-wave duration (101.7 vs. 117.2 ms), PQ interval (175.8 vs. 198.0 ms), QRS interval (89.9 vs. 97.7 ms), and QTc interval (402.8 vs. 421.2 ms). We further examined ECG waveform prolongations related to BMI. Compared to other patient groups, the morbidly obese patients had the highest number of ECG segments with PQ interval (44% of the ECG samples), QRS duration (14%), and QTc duration (20%) above the normal limits.

CONCLUSIONS

Morbid obesity predisposes patients to prolongation of cardiac conduction times. This might increase the risk of arrhythmias, stroke, and even sudden cardiac death.

Association of time-varying sleep duration and cognitive function with mortality in the elderly: a 12-year community-based cohort study

BACKGROUND

Sleeping problems and cognitive impairment are common in elders. Baseline sleep duration and cognitive status are predictors of mortality. But few studies have explored whether longitudinal changes in sleep duration and cognitive function are related to mortality in older adults. The present study investigated the time-varying relationships of sleep duration and cognitive function with subsequent mortality among community-dwelling elders by using 12 years of repeated-measure data.

METHODS

Taichung Community Health Study for Elders (TCHS-E) is a retrospective, population-based cohort that started in 2009 (wave 1) with a total of 912 elders aged 65 years or above. Follow up was conducted in 2010 (wave 2), 2018 (wave 3), and 2020 (wave 4). Sleep duration and Mini-Mental State Examination (MMSE) forms were executed at baseline and three visits during follow-up. Time-varying Cox proportional hazards regression estimated adjusted hazard ratios (HRs) of mortality with 95% confidence intervals (CIs).

RESULTS

During about 12 years (9,396 person-years) follow-up, 329 deaths from all causes were documented, including 102 deaths due to expanded cardiovascular disease (CVD). In the multivariable-adjusted, time-varying Cox proportional hazard model, the adjusted HR values of all-cause mortality were 1.47 (1.02-2.12) for sleep duration > 9 h/day (vs. 7 h/day) and 1.81 (1.26-2.59) for MMSE < 27 (vs. 30). The adjusted HR values of the expanded CVD mortality were 2.91 (1.24-6.83) for MMSE of 29; 2.69 (1.20-6.05) for MMSE of 27-28; and 4.32 (95% CI: 1.92-9.74) for MMSE < 27. The dose-dependent relationship was significant (p < 0.001). The combinations of sleep duration longer than 9 h/day and MMSE < 27 were linked with the highest risks for expanded CVD and all-cause mortality.

CONCLUSIONS

Long sleep duration and low cognitive function were jointly and independently linked with higher risk of mortality in elders residing in community.

Rat models of diet-induced obesity and metabolic dysregulation: Current trends, shortcomings and considerations for future research

Rat diet-induced obesity and metabolic dysregulation (DIO/DIMD) is widely used as a pre-clinical model for human obesity and for testing weight-loss interventions. The aim of this review was to utilise a systematic literature survey of rat DIO/DIMD studies as a tool to document trends around study design and metabolic outcomes of these studies, and to consider ways in which the design of these studies may be improved to enhance the relevance thereof for human obesity research. In total, 110 comparisons between control and obesogenic dietary groups were included in the survey. Young male rats were found to be the model of choice, but fewer than 50% of studies provided comprehensive information about diet composition and energy intake. In addition, it was found that the majority of expected DIO/DIMD responses (hyperglycemia, hyperinsulinemia, dyslipidemia, hypoadiponectinemia) occurred at < 80% frequency, drawing into question the concept of a "typical" or "appropriate" response. We discuss the impact of differences in diet composition and energy intake on metabolic outcomes against the context of large heterogeneity of obesogenic diets employed in rat DIO/DIMD studies, and provide recommendations for the improvement of reporting standards around diet composition and dietary intake. In addition, we highlight the lack of data from female and older rats and describe considerations around the inclusion of sex and age as a variable in rat DIO/DIMD studies, aiming towards improving the applicability of these studies as a model of human obesity, which is most prevalent in women and older individuals.

Effects of weight loss and weight loss maintenance on cardiac autonomic function in obesity: a randomized controlled trial

NOVELTY

Caloric restriction and exercise exert significant improvements in cardiac autonomic function as measured by HRV in overweight and obesity. Aerobic exercise training, within recommended guidelines coupled with weight loss maintenance, retains cardiac autonomic function benefits from weight loss in previously obese individuals.

Brain Dopamine-Clock Interactions Regulate Cardiometabolic Physiology: Mechanisms of the Observed Cardioprotective Effects of Circadian-Timed Bromocriptine-QR Therapy in Type 2 Diabetes Subjects

Despite enormous global efforts within clinical research and medical practice to reduce cardiovascular disease(s) (CVD), it still remains the leading cause of death worldwide. While genetic factors clearly contribute to CVD etiology, the preponderance of epidemiological data indicate that a major common denominator among diverse ethnic populations from around the world contributing to CVD is the composite of Western lifestyle cofactors, particularly Western diets (high saturated fat/simple sugar [particularly high fructose and sucrose and to a lesser extent glucose] diets), psychosocial stress, depression, and altered sleep/wake architecture. Such Western lifestyle cofactors are potent drivers for the increased risk of metabolic syndrome and its attendant downstream CVD. The central nervous system (CNS) evolved to respond to and anticipate changes in the external (and internal) environment to adapt survival mechanisms to perceived stresses (challenges to normal biological function), including the aforementioned Western lifestyle cofactors. Within the CNS of vertebrates in the wild, the biological clock circuitry surveils the environment and has evolved mechanisms for the induction of the obese, insulin-resistant state as a survival mechanism against an anticipated ensuing season of low/no food availability. The peripheral tissues utilize fat as an energy source under muscle insulin resistance, while increased hepatic insulin resistance more readily supplies glucose to the brain. This neural clock function also orchestrates the reversal of the obese, insulin-resistant condition when the low food availability season ends. The circadian neural network that produces these seasonal shifts in metabolism is also responsive to Western lifestyle stressors that drive the CNS clock into survival mode. A major component of this natural or Western lifestyle stressor-induced CNS clock neurophysiological shift potentiating the obese, insulin-resistant state is a diminution of the circadian peak of dopaminergic input activity to the pacemaker clock center, suprachiasmatic nucleus. Pharmacologically preventing this loss of circadian peak dopaminergic activity both prevents and reverses existing metabolic syndrome in a wide variety of animal models of the disorder, including high fat-fed animals. Clinically, across a variety of different study designs, circadian-timed bromocriptine-QR (quick release) (a unique formulation of micronized bromocriptine-a dopamine D2 receptor agonist) therapy of type 2 diabetes subjects improved hyperglycemia, hyperlipidemia, hypertension, immune sterile inflammation, and/or adverse cardiovascular event rate. The present review details the seminal circadian science investigations delineating important roles for CNS circadian peak dopaminergic activity in the regulation of peripheral fuel metabolism and cardiovascular biology and also summarizes the clinical study findings of bromocriptine-QR therapy on cardiometabolic outcomes in type 2 diabetes subjects.

Association of Serum Leptin and Adiponectin Concentrations with Type 2 Diabetes Biomarkers and Complications Among Saudi Women

Objective

Hyperglycemia and insulin resistance (IR) put obese women with Type 2 diabetes mellitus (T2DM) at risk for cardiovascular disease (CVD).

Methods

150 T2DM women aged 30-45 were studied cross-sectionally at Madinah Hospital lab to find T2DM risk factors and their association with adiponectin/leptin levels.

Results

Women with T2DM showed greater fasting blood glucose (FBG), hemoglobin A1c (HbA1c), triglycerides (TG), body mass index (BMI), waist circumference (WC), insulin resistance (IR), high-sensitivity C-reactive protein (hs-CRP), and CVD risk (high atherogenic index of plasma (AIP) and leptin), but decreased high-density lipoprotein (HDL-cholesterol) and poor insulin sensitivity with low adiponectin. Obese women with T2DM had increased leptin and reduced adiponectin. Leptin levels were significantly related to IR, BMI, and AIP (B= 3.97, P= 0.02) but not WC. Leptin levels were negatively correlated with insulin sensitivity (IS) and HDL-c (P< 0.05). In linear regression analysis, adiponectin levels had a significant association with IS and HDL-c (P= 0.03, P= 0.04) but an inverse relationship with IR, BMI, WC (B=-2.91, P= 0.04), and AIP (P< 0.05).

Conclusion

Increased leptin levels are related to high IR, AIP, and BMI among T2DM female patients. Similarly, adiponectin levels decrease IS and HDL-c. Therefore, obese T2DM women with high leptin and low adiponectin levels should be periodically checked to avoid or decrease consequences like CVD.

GDF15 promotes weight loss by enhancing energy expenditure in muscle

Caloric restriction that promotes weight loss is an effective strategy for treating non-alcoholic fatty liver disease and improving insulin sensitivity in people with type 2 diabetes1. Despite its effectiveness, in most individuals, weight loss is usually not maintained partly due to physiological adaptations that suppress energy expenditure, a process known as adaptive thermogenesis, the mechanistic underpinnings of which are unclear2,3. Treatment of rodents fed a high-fat diet with recombinant growth differentiating factor 15 (GDF15) reduces obesity and improves glycaemic control through glial-cell-derived neurotrophic factor family receptor α-like (GFRAL)-dependent suppression of food intake4-7. Here we find that, in addition to suppressing appetite, GDF15 counteracts compensatory reductions in energy expenditure, eliciting greater weight loss and reductions in non-alcoholic fatty liver disease (NAFLD) compared to caloric restriction alone. This effect of GDF15 to maintain energy expenditure during calorie restriction requires a GFRAL-β-adrenergic-dependent signalling axis that increases fatty acid oxidation and calcium futile cycling in the skeletal muscle of mice. These data indicate that therapeutic targeting of the GDF15-GFRAL pathway may be useful for maintaining energy expenditure in skeletal muscle during caloric restriction.

Effects of a Mobile-Health Exercise Intervention on Body Composition, Vascular Function, and Autonomic Nervous System Function in Obese Women: A Randomized Controlled Trial

Purpose

The present study verified the effect of an m-health exercise intervention using a 12-week exercise program on body composition, vascular function, and the ANS.

Patients and Methods

Thirty obese adult women participants were randomized (n = 15 each) into the experimental (EXP) group, those who performed mobile-health (m-health) exercises using a wearable device (Charge 4, Fitbit, USA) and AI-fit web page, or the control (CON) group, those who continued their daily activities as before. Muscle function, cardiorespiratory endurance, and flexibility were assessed during the exercise program using the AI-fit web page and wearable device. The EXP group participated in exercise interventions using the m-health system for 12 weeks, while the CON group was encouraged to maintain their normal daily routines. Body composition, vascular function, and autonomic nervous system (ANS) were evaluated before and after the intervention.

Results

Significant decreases were noted in fat mass (Post - Pre: -1.47 kg; p < 0.001) and percent body fat (Post - Pre: -2.11%; p < 0.05). Flow-mediated dilatation (Post - Pre: 2.63%; p < 0.001) was significantly increased, and brachial-ankle pulse wave velocity (Post - Pre: -91.49 cm·sec^-1; p < 0.01) was significantly decreased. RMSSD (Post - Pre: 10.43 ms; p < 0.01), NN50 (Post-Pre: 24.04; p < 0.05), pNN50 (Post - Pre: 7.70%; p < 0.05) and HF (Post-Pre: 179.60 ms²; p < 0.05) increased significantly.

Conclusion

In conclusion, m-health exercise interventions using AI fit and wearable devices are effective in preventing obesity and improving vascular function, and ANS.

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD): a collaborative review of the current understanding

PURPOSE

To provide an overview of the discovery, presentation, and management of Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation, and Autonomic Dysregulation (ROHHAD). To discuss a search for causative etiology spanning multiple disciplines and continents.

METHODS

The literature (1965-2022) on the diagnosis, management, pathophysiology, and potential etiology of ROHHAD was methodically reviewed. The experience of several academic centers with expertise in ROHHAD is presented, along with a detailed discussion of scientific discovery in the search for a cause.

RESULTS

ROHHAD is an ultra-rare syndrome with fewer than 200 known cases. Although variations occur, the acronym ROHHAD is intended to alert physicians to the usual sequence or unfolding of the phenotypic presentation, including the full phenotype. Nearly 60 years after its first description, more is known about the pathophysiology of ROHHAD, but the etiology remains enigmatic. The search for a genetic mutation common to patients with ROHHAD has not, to date, demonstrated a disease-defining gene. Similarly, a search for the autoimmune basis of ROHHAD has not resulted in a definitive answer. This review summarizes current knowledge and potential future directions.

CONCLUSION

ROHHAD is a poorly understood, complex, and potentially devastating disorder. The search for its cause intertwines with the search for causes of obesity and autonomic dysregulation. The care for the patient with ROHHAD necessitates collaborative international efforts to advance our knowledge and, thereby, treatment, to decrease the disease burden and eventually to stop, and/or reverse the unfolding of the phenotype.

Natural products targeting inflammation-related metabolic disorders: A comprehensive review

Currently, the incidence of metabolic disorders is increasing, setting a challenge to global health. With major advancement in the diagnostic tools and clinical procedures, much has been known in the etiology of metabolic disorders and their corresponding pathophysiologies. In addition, the use of in vitro and in vivo experimental models prior to clinical studies has promoted numerous biomedical breakthroughs, including in the discovery and development of drug candidates to treat metabolic disorders. Indeed, chemicals isolated from natural products have been extensively studied as prospective drug candidates to manage diabetes, obesity, heart-related diseases, and cancer, partly due to their antioxidant and anti-inflammatory properties. Continuous efforts have been made in parallel to improve their bioactivity and bioavailability using selected drug delivery approaches. Here, we provide insights on recent progress in the role of inflammatory-mediated responses on the initiation of metabolic disorders, with particular reference to diabetes mellitus, obesity, heart-related diseases, and cancer. In addition, we discussed the prospective role of natural products in the management of diabetes, obesity, heart-related diseases, and cancers and provide lists of potential biological targets for high throughput screening in drug discovery and development. Lastly, we discussed findings observed in the preclinical and clinical studies prior to identifying suitable approaches on the phytochemical drug delivery systems that are potential to be used in the treatment of metabolic disorders.

The Influence of Obesity in the Autonomic Nervous System Activity in School-Aged Children in Northern Portugal: A Cross-Sectional Study

INTRODUCTION

Obesity is one of the most prevalent chronic diseases in childhood, being an important public health issue. Excessive weight has been associated with autonomic dysfunction but the evidence in children is scarce. Therefore, the aim of this study was to assess the effect of overweight and obesity on the autonomic nervous system activity, in children.

MATERIAL AND METHODS

Data from a cross-sectional study of 1602 children, aged 7 to 12 years, was used and 858 children were included in the analysis. Body mass index was calculated and classified according to criteria of the World Health Organization (WHO), Centers for Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF). Body composition was characterized by bioelectrical impedance. Linear regression models were used to determine the association between body mass index, body composition and the autonomic nervous system activity, assessed by pupillometry.

RESULTS

Average dilation velocity was higher among children with obesity, according to the CDC and percentage of body fat criteria (β = 0.053, 95% CI = 0.005 to 0.101 and β = 0.063, 95% CI = 0.016 to 0.109, respectively). The same trend was observed for WHO and IOTF criteria (β = 0.045, 95% CI = -0.001 to 0.091, and β = 0.055, 95% CI = -0.001 to 0.111, respectively). CDC and WHO body mass index z-scores were also positively associated with the values of average dilation velocity (rs = 0.030, p = 0.048; and rs = 0.027, p = 0.042, respectively).

CONCLUSION

Our findings suggest an association between body mass and changes in the autonomic activity, Moreover, this study provides proof of concept for interventions targeting the prevention/treatment of obesity in children that may offer some benefit in re-establishing the balance of the autonomic nervous system, and subsequently preventing the consequences associated with the autonomic nervous system dysfunction.

Thermoregulatory responses, heart rate, and the susceptibility to anxiety in obese animals subjected to stress

Obesity and stress are related to cardiovascular diseases. Rats fed a high-fat diet (HFD) show increased cardiovascular reactivity to emotional stress and altered defensive behavioral responses. Indeed, changes in thermoregulatory responses in an aversive environment are observed in these animals. However, studies aimed at clarifying the physiological mechanisms linking obesity, stress hyperreactivity and behavioral changes are needed. The aim of this study was to evaluate the changes in thermoregulatory responses, heart rate, and the susceptibility to anxiety in obese animals subjected to stress. Nine-week high-fat diet protocol was effective in inducing obesity by increasing weight gain, fat mass, adiposity index, white epididymal, retroperitoneal, inguinal and brown adipose tissue. Animals induced to obesity and subjected to stress (HFDS group) by the intruder animal method showed increases in heart rate (HR), core body temperature and tail temperature. HFDS showed an increase in the first exposure to the closed arm (anxiety-like behavior) in elevated T-Maze (ETM). The groups did not differ with respect to panic behavior assessed in the ETM and locomotor activity in the open field test. Our study shows that HFDS animals presented increased reactivity to stress with higher stress hyperthermia and anxious behavior. Thus, our results present relevant information regarding stress responsiveness and behavioral changes in obese animals.

Genome-wide screening for genetic variants in polyadenylation signal (PAS) sites in mouse selection lines for fatness and leanness

Alternative polyadenylation (APA) determines mRNA stability, localisation, translation and protein function. Several diseases, including obesity, have been linked to APA. Studies have shown that single nucleotide polymorphisms in polyadenylation signals (PAS-SNPs) can influence APA and affect phenotype and disease susceptibility. However, these studies focussed on associations between single PAS-SNP alleles with very large effects and phenotype. Therefore, we performed a genome-wide screening for PAS-SNPs in the polygenic mouse selection lines for fatness and leanness by whole-genome sequencing. The genetic variants identified in the two lines were overlapped with locations of PAS sites obtained from the PolyASite 2.0 database. Expression data for selected genes were extracted from the microarray expression experiment performed on multiple tissue samples. In total, 682 PAS-SNPs were identified within 583 genes involved in various biological processes, including transport, protein modifications and degradation, cell adhesion and immune response. Moreover, 63 of the 583 orthologous genes in human have been previously associated with human diseases, such as nervous system and physical disorders, and immune, endocrine, and metabolic diseases. In both lines, PAS-SNPs have also been identified in genes broadly involved in APA, such as Polr2c, Eif3e and Ints11. Five PAS-SNPs within 5 genes (Car, Col4a1, Itga7, Lat, Nmnat1) were prioritised as potential functional variants and could contribute to the phenotypic disparity between the two selection lines. The developed PAS-SNPs catalogue presents a key resource for planning functional studies to uncover the role of PAS-SNPs in APA, disease susceptibility and fat deposition.

Food readjustment plus exercise training improves cardiovascular autonomic control and baroreflex sensitivity in high-fat diet-fed ovariectomized mice

Despite consensus on the benefits of food readjustment and/or moderate-intensity continuous exercise in the treatment of cardiometabolic risk factors, there is little evidence of the association between these two cardiovascular risk management strategies after menopause. Thus, the objective of this study was to evaluate the effects of food readjustment and/or exercise training on metabolic, hemodynamic, autonomic, and inflammatory parameters in a model of loss of ovarian function with diet-induced obesity. Forty C57BL/6J ovariectomized mice were divided into the following groups: high-fat diet-fed - 60% lipids throughout the protocol (HF), food readjustment - 60% lipids for 5 weeks, readjusted to 10% for the next 5 weeks (FR), high-fat diet-fed undergoing moderate-intensity exercise training (HFT), and food readjustment associated with moderate-intensity exercise training (FRT). Blood glucose evaluations and oral glucose tolerance tests were performed. Blood pressure was assessed by direct intra-arterial measurement. Baroreflex sensitivity was tested using heart rate phenylephrine and sodium nitroprusside induced blood pressure changes. Cardiovascular autonomic modulation was evaluated in time and frequency domains. Inflammatory profile was evaluated by IL-6, IL-10 cytokines, and TNF-alpha measurements. Only the exercise training associated with food readjustment strategy induced improved functional capacity, body composition, metabolic parameters, inflammatory profile, and resting bradycardia, while positively changing cardiovascular autonomic modulation and increasing baroreflex sensitivity. Our findings demonstrate that the association of these strategies seems to be effective in the management of cardiometabolic risk in a model of loss of ovarian function with diet-induced obesity.

Body fat and muscle in relation to heart rate variability in young-to-middle age men: a cross sectional study

BACKGROUND

While obesity is recognisably associated with changes in heart rate variability (HRV), the association between skeletal muscle mass and HRV is less clear.

AIMS

In this cross sectional study, we analysed the association of body fat (four parameters) and muscle mass (five parameters) with indicators of HRV activity.

SUBJECTS AND METHODS

Assessment of body composition and HRV was performed in n = 180 young-to-middle age healthy men exposed to high occupational physical activity, using the multi-frequency bioelectrical impedance device and the PPG-StressFlow® HRV photoplethysmography device, respectively.

RESULTS

Mean values of parameters of fat tissue were above normal/reference values. Muscle tissue indicators were higher or within the reference ranges. Fat tissue parameters were significantly higher in participants with lower parasympathetic nervous system (PNS) indicators. Weight-adjusted skeletal muscle index (wSMI) was significantly lower in men with reduced PNS parameters. Fat tissue parameters were negatively correlated with PNS parameters, while wSMI was positively correlated with PNS parameters.

CONCLUSIONS

Participants with higher fat mass and lower muscle mass had poorer parasympathetic activity. Since mean values of HRV parameters indicated mild parasympathetic dominance, we conclude that physical activity and consequently good muscle mass potentially compensated for the negative interaction between fat tissue and HRV.

Identification of a novel link between adiposity and visuospatial perception

OBJECTIVE

Recent work has reported a negative association between BMI and performance on the Penn Line Orientation Task. To determine the reliability of this effect, a comprehensive assessment of visual function in individuals with healthy weight (HW) and those with overweight/obesity (OW/OB) was performed.

METHODS

Visual acuity/contrast, Penn Line Orientation Task, and higher-order visuospatial function were measured in 80 (40 with HW, 40 with OW/OB) case-control study participants. Adiposity, fasting glucose, hemoglobin A1c, diet, physical activity, and heart rate variability were also assessed. A subgroup of 22 participants plus 5 additional participants (n = 27) underwent functional magnetic resonance imaging scanning.

RESULTS

Compared with those with HW, individuals with OW/OB performed worse on tasks requiring judgments of line orientation. This effect was mediated by body fat percentage and was unrelated to other measures. Functional magnetic resonance imaging revealed a negative association between BMI and response in the primary visual cortex (V1) during line orientation judgment. Performance was unrelated to V1 response but positively correlated with response in a network of regions, including the lateral occipital cortex, when BMI was accounted for in the model.

CONCLUSIONS

These results demonstrate a selective deficit in line orientation perception associated with adiposity and blunted activation in the V1 that cannot be attributed to visual acuity and does not generalize to other visuospatial tasks.

Gender Differences and Cardiometabolic Risk: The Importance of the Risk Factors

Metabolic syndrome (Mets) is a clinical condition characterized by a cluster of major risk factors for cardiovascular disease (CVD) and type 2 diabetes: proatherogenic dyslipidemia, elevated blood pressure, dysglycemia, and abdominal obesity. Each risk factor has an independent effect, but, when aggregated, they become synergistic, doubling the risk of developing cardiovascular diseases and causing a 1.5-fold increase in all-cause mortality. We will highlight gender differences in the epidemiology, etiology, pathophysiology, and clinical expression of the aforementioned Mets components. Moreover, we will discuss gender differences in new biochemical markers of metabolic syndrome and cardiovascular risk.

Imperatorin Improves Obesity-Induced Cardiac Sympathetic Nerve Injury Mediated by P2X4 Receptor in Stellate Sympathetic Ganglion

Obesity can activate the inflammatory signal pathway, induce in the body a state of chronic inflammation, and increase the excitability of the sympathetic nervous system, which may induce sympathetic neuropathic injury. The stellate sympathetic ganglia (SG) can express the P2X4 receptor, and the abnormal expression of the P2X4 receptor is related to inflammation. Imperatorin (IMP) is a kind of furan coumarin plant which has anti-inflammatory effects. This project aimed to investigate whether IMP can affect the expression of P2X4 receptors in the SG of obese rats to display a protective effect from high-fat-triggered cardiac sympathetic neuropathic injury. Molecular docking through homology modelling revealed that IMP had good affinity for the P2X4 receptor. Our results showed that compared with the normal group, the administration of IMP or P2X4 shRNA decreased sympathetic excitement; reduced the serum levels of triglyceride, total cholesterol, and lactate dehydrogenase; downregulated the expression of P2X4 receptors in SG; and inhibited the expression of inflammatory factors in the SG and serum of obese rats significantly. In addition, the expression of factors associated with the cell pyroptosis GSDMD, caspase-1, NLRP-3, and IL-18 in obese rats were significantly higher than those of the normal rats, and such effects were decreased after treatment with IMP or P2X4 shRNA. Furthermore, IMP significantly reduced the ATP-activated currents in HEK293 cells transfected with P2X4 receptor. Thus, the P2X4 receptor may be a key target for the treatment of obesity-induced cardiac sympathetic excitement. IMP can improve obesity-induced cardiac sympathetic excitement, and its mechanism of action may be related to the inhibition of P2X4 receptor expression and activity in the SG, suppression of cellular pyroptosis in the SG, and reduction of inflammatory factor levels.

Diabetes-Induced Cardiac Autonomic Neuropathy: Impact on Heart Function and Prognosis

Cardiovascular autonomic neuropathy (CAN) is a severe complication of the advance stage of diabetes. More than 50% of diabetic patients diagnosed with peripheral neuropathy will have CAN, with clinical manifestations including tachycardia, severe orthostatic hypotension, syncope, and physical exercise intolerance. Since the prevalence of diabetes is increasing, a concomitant increase in CAN is expected and will reduce quality of life and increase mortality. Autonomic dysfunction is associated with reduced baroreflex sensitivity and impairment of sympathetic and parasympathetic modulation. Various autonomic function tests are used to diagnose CAN, a condition without adequate treatment. It is important to consider the control of glucose level and blood pressure as key factors for preventing CAN progression. However, altered biomarkers of inflammatory and endothelial function, increased purinergic receptor expression, and exacerbated oxidative stress lead to possible targets for the treatment of CAN. The present review describes the molecular alterations seen in CAN, diagnosis, and possible alternative treatments.

Non-alcoholic fatty liver disease (NAFLD) and mental illness: Mechanisms linking mood, metabolism and medicines

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the world and one of the leading indications for liver transplantation. It is one of the many manifestations of insulin resistance and metabolic syndrome as well as an independent risk factor for cardiovascular disease. There is growing evidence linking the incidence of NAFLD with psychiatric illnesses such as schizophrenia, bipolar disorder and depression mechanistically via genetic, metabolic, inflammatory and environmental factors including smoking and psychiatric medications. Indeed, patients prescribed antipsychotic medications, regardless of diagnosis, have higher incidence of NAFLD than population norms. The mechanistic pharmacology of antipsychotic-associated NAFLD is beginning to emerge. In this review, we aim to discuss the pathophysiology of NAFLD including its risk factors, insulin resistance and systemic inflammation as well as its intersection with psychiatric illnesses.

Cardiolipin Alterations during Obesity: Exploring Therapeutic Opportunities

Cardiolipin is a specific phospholipid of the mitochondrial inner membrane that participates in many aspects of its organization and function, hence promoting proper mitochondrial ATP production. Here, we review recent data that have investigated alterations of cardiolipin in different tissues in the context of obesity and the related metabolic syndrome. Data relating perturbations of cardiolipin content or composition are accumulating and suggest their involvement in mitochondrial dysfunction in tissues from obese patients. Conversely, cardiolipin modulation is a promising field of investigation in a search for strategies for obesity management. Several ways to restore cardiolipin content, composition or integrity are emerging and may contribute to the improvement of mitochondrial function in tissues facing excessive fat storage. Inversely, reduction of mitochondrial efficiency in a controlled way may increase energy expenditure and help fight against obesity and in this perspective, several options aim at targeting cardiolipin to achieve a mild reduction of mitochondrial coupling. Far from being just a victim of the deleterious consequences of obesity, cardiolipin may ultimately prove to be a possible weapon to fight against obesity in the future.

Effects of weight loss through lifestyle changes on heart rate variability in overweight and obese patients: A systematic review

BACKGROUND & AIMS

The effects of calorie restriction and physical activity on autonomic regulation and cardiac vagal control in overweight and obese individuals remain inconsistent. Thus, this systematic review aimed to evaluate the weight loss effects through lifestyle changes on heart rate variability (HRV) markers in overweight and obese subjects.

METHODS

A systematic search for studies published up to November 2021 was conducted in MEDLINE, Embase, EBSCO host and VHL REGIONAL/LILACS. The main outcomes were changes in HRV indices from pre- and post-nutritional intervention and exercise in overweight and obese individuals. This review was registered in PROSPERO: CRD42021274467.

RESULTS

The literature search retrieved 959 articles, of which 12 were included in this review. The intervention in nine studies was diet only, in two studies was diet and exercise, and in one study diet was compared to diet and exercise. The weight loss was greater than 10% in four studies and between 5 and 10% in three studies. Most of the studies revealed that weight loss through lifestyle changes seems to promote beneficial effects on HRV, restoring sympathovagal balance by increasing parasympathetic activity and reducing sympathetic activation.

CONCLUSION

This systematic review exhibited the beneficial effects of weight loss through lifestyle changes on cardiac autonomic control in overweight and obese individuals. Future investigations need standardization of HRV indices for better interpretation of autonomic function in different clinical situations.

Cardiac autonomic dysfunction in school age children with overweight and obesity

BACKGROUND AND AIMS

We investigated cardiac autonomic function in overweight and obese school-age children.

METHODS AND RESULTS

Quantitative cross-sectional study conducted with children (n = 110) of both genders. Children were divided by normal weight (NW; n = 54), overweight (OW; n = 24) and obese (OB; n = 32). Systolic (SBP) and diastolic (DBP) blood pressure and electrocardiograms were recorded and analyzed for heart rate and the heart rate variability (HRV) in time (SDRR, RMSSD, PRR50, SD1 and SD2) and frequency domains (HF, LF and LF/HF). The OB group presented higher SBP (p ≤ 0.01) and DBP (p ≤ 0.01). For HRV, the OB group had a lower PRR50 (p ≤ 0.01) and HF (p ≤ 0.01), associated with higher LF (p ≤ 0.01). Moderate negative correlations were found between the HF, BMI (r = -0.37; p ≤ 0.01) and WC (r = -0.38; p ≤ 0.01). Positive moderate correlation were found between LF, LF/HF and BMI (LF: r = 0.32; p ≤ 0.01; LF/HF: r = 0.31; p ≤ 0.01) and WC (LF: r = 0.34; p ≤ 0.01; LF/HF: = 0.34; p ≤ 0.01). Multiple linear regression showed a positive association between body fat and the SDRR (β: 0.48; CI: 0.2-4.2; p = 0.02). No differences were observed in cardiac electrical activity.

CONCLUSION

Children with obesity but not overweight presented higher blood pressure and cardiac autonomic dysfunction, with sympathetic predominance on the heart rate. This fact was positively correlated with BMI and may be considered an important marker for cardiovascular risk in children.

Experiences and perceptions of nutritional health and wellbeing amongst food insecure women in Europe: A qualitative meta-ethnography

Since the 2008 global financial crisis, there has been a rise in the number of people experiencing food insecurity. Particularly vulnerable are mothers with young children, pregnant women, and lone parents (the majority of whom are women). This systematic review and meta-ethnography of qualitative studies focused on women's experiences of food insecurity and how it affects their nutritional health and wellbeing. Six electronic databases (Medline, Scopus, Web of Science, EMBASE, CINAHL and ASSIA), were searched from January 1, 2008-July 10, 2021, and supplemented by searches of grey literature databases, relevant websites, examination of reference lists and citation searches. We adhered to PRISMA and eMERGe guidelines to improve the completeness and clarity of meta-ethnographic reporting. Methodological quality of the studies was assessed using the Critical Appraisal Skills Programme qualitative checklist. We identified 11,589 unique records; we included 23 publications reporting data from 22 unique studies involving 647 women. Data were synthesised according to Noblit & Hare's seven phases of meta-ethnography. We identified two key themes - accessing sufficient food and embodying food insecurity - comprising seven sub-themes. Our meta-ethnography provides a progressive 'storyline' of women's experiences of food insecurity. This includes the ways in which women attempt to access sufficient food, are unable to meet their nutritional needs, and the ways in which this is embedded into their everyday lives and embodied in unhealthful physical, social, and mental nutritional health and wellbeing impacts. Our review emphasises that food insecurity directly and tangibly impacts women's nutritional health and wellbeing. It concludes that there needs to be greater recognition of the psychosocial impact of food insecurity on vulnerable women in addition to its impact on their nutritional health and wellbeing.

Progressive Additive Benefits of Prehabilitation and Subsequent Bariatric Surgery on Cardiac Autonomic Regulation as Assessed by Means of a Simple Unitary Composite Index: Preliminary Data from an Observational Study

Obesity is associated with an increased risk of several chronic comorbidities, which may also be determined by dysfunctional autonomic nervous system (ANS). The influence of bariatric surgery (BS) on ANS balance was explored in previous studies, but with high heterogeneity in both the assessment timing and methods employed. In the present observational study, we applied a clinical protocol which considers two subsequent phases. Twenty-nine non-diabetic obese subjects were studied at baseline (T0), after one month of lifestyle modification (prehabilitation) (phase 1-T1), and after eight months following BS (phase 2-T2). ANS regulation was assessed across the three study epochs by means of ANSI, a single composite percent-ranked proxy of autonomic balance, being free of gender and age bias, economical and simple to apply in a clinical setting. The aim of the present study was to investigate the effects of the clinical protocol based on prehabilitation and subsequent BS on the ANS regulation by means of ANSI. Potential intertwined correlations with metabolic parameters were also investigated. Notably, we observed a progressive improvement in ANS control, even by employing ANSI. Moreover, the reduction in the markers of sympathetic overactivity was found to significantly correlate with the amelioration in some metabolic parameters (fasting glucose, insulin levels, and waist circumference), as well as in stress and tiredness perception. In conclusion, this study provides convincing evidence that a unitary proxy of cardiac autonomic regulation (CAR) may reflect the progressive improvement in autonomic regulation following behavioral and surgical interventions in obese patients. Intriguingly, this might contribute to reducing cardiovascular and metabolic risk.

The molecular signaling of exercise and obesity in the microbiota-gut-brain axis

Obesity is one of the major pandemics of the 21st century. Due to its multifactorial etiology, its treatment requires several actions, including dietary intervention and physical exercise. Excessive fat accumulation leads to several health problems involving alteration in the gut-microbiota-brain axis. This axis is characterized by multiple biological systems generating a network that allows bidirectional communication between intestinal bacteria and brain. This mutual communication maintains the homeostasis of the gastrointestinal, central nervous and microbial systems of animals. Moreover, this axis involves inflammatory, neural, and endocrine mechanisms, contributes to obesity pathogenesis. The axis also acts in appetite and satiety control and synthesizing hormones that participate in gastrointestinal functions. Exercise is a nonpharmacologic agent commonly used to prevent and treat obesity and other chronic degenerative diseases. Besides increasing energy expenditure, exercise induces the synthesis and liberation of several muscle-derived myokines and neuroendocrine peptides such as neuropeptide Y, peptide YY, ghrelin, and leptin, which act directly on the gut-microbiota-brain axis. Thus, exercise may serve as a rebalancing agent of the gut-microbiota-brain axis under the stimulus of chronic low-grade inflammation induced by obesity. So far, there is little evidence of modification of the gut-brain axis as a whole, and this narrative review aims to address the molecular pathways through which exercise may act in the context of disorders of the gut-brain axis due to obesity.

The Peripheral Neuropathy Prevalence and Characteristics Are Comparable in People with Obesity and Long-Duration Type 1 Diabetes

Introduction

Peripheral neuropathy is reported in obesity even in the absence of hyperglycaemia.

Objective

To compare the prevalence and characterise the phenotype of peripheral neuropathy in people living with obesity (OB) and long-duration type 1 diabetes (T1D).

Patients and Methods

We performed a prospective cross-sectional study of 130 participants including healthy volunteers (HV) (n = 28), people with T1D (n = 51), and OB (BMI 30–50 kg/m²) (n = 51). Participants underwent assessment of neuropathic symptoms (Neuropathy Symptom Profile, NSP), neurological deficits (Neuropathy Disability Score, NDS), vibration perception threshold (VPT) and evaluation of sural nerve conduction velocity and amplitude.

Results

Peripheral neuropathy was present in 43.1% of people with T1D (age 49.9 ± 12.9 years; duration of diabetes 23.4 ± 13.5 years) and 33.3% of OB (age 48.2 ± 10.8 years). VPT for high risk of neuropathic foot ulceration (VPT ≥ 25 V) was present in 31.4% of T1D and 19.6% of OB. Participants living with OB were heavier (BMI 42.9 ± 3.5 kg/m²) and had greater centripetal adiposity with an increased body fat percentage (FM%) (P < 0.001) and waist circumference (WC) (P < 0.001) compared to T1D. The OB group had a higher NDS (P < 0.001), VAS for pain (P < 0.001), NSP (P < 0.001), VPT (P < 0.001) and reduced sural nerve conduction velocity (P < 0.001) and amplitude (P < 0.001) compared to HV, but these parameters were comparable in T1D. VPT was positively associated with increased WC (P = 0.011), FM% (P = 0.001) and HbA1c (P < 0.001) after adjusting for age (R² = 0.547). Subgroup analysis of respiratory quotient (RQ) measured in the OB group did not correlate with VPT (P = 0.788), nerve conduction velocity (P = 0.743) or amplitude (P = 0.677).

Conclusion

The characteristics of peripheral neuropathy were comparable between normoglycaemic people living with obesity and people with long-duration T1D, suggesting that metabolic factors linked to obesity play a pivotal role in the development of peripheral neuropathy. Further studies are needed to investigate the mechanistic link between visceral adiposity and neuropathy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-022-02208-z.

Significant Decrease in Glycated Hemoglobin, 2h-Post-Load Glucose and High-Sensitivity C-Reactive Protein Levels in Patients with Abnormal Body Mass Index after Therapy with Manual Lymphatic Drainage

The objective of this study was to investigate the effect of manual lymphatic drainage (MLD) on the insulin resistance parameter (HOMA-IR), glycated hemoglobin (HbA1c), C-peptide, insulin, fasting plasma glucose (FPG), 2h-post-loadglucose (2h-PG) and the concentration of high-sensitivity C-reactive protein (hsCRP) in patients with abnormal body mass index. The study involved 30 patients, including patients with normal body weight (as a control group; group I; n = 14), overweight patients (group II; n = 9) and obese patients (group III; n = 7). Each patient underwent 10 sessions of MLD therapy, 3 times a week for 30 min. In addition, we measured body mass index (BMI) and waist-to-hip ratio (WHR) and performed body composition analysis as well as biochemical tests before MLD therapy (stage 0′) and after MLD therapy (stage 1′). A statistically significant correlation was demonstrated between the concentration of C-peptide, BMI, the amount of visceral adipose tissue (r = 0.87, p = 0.003; r = 0.76, p = 0.003, respectively), and the HOMA-IR index, BMI and the amount of visceral adipose tissue (r = 0.86, p = 0.005; r = 0.84, p = 0.042, respectively), before and after MLD therapy. In overweight patients (group II), a statistically significant (p = 0.041) decrease in the hsCRP level by 2.9 mg/L and a significant (p = 0.050) decrease in the 2h-PG level by 12 mg/dL after the MLD therapy was detected. Moreover, in the group of obese patients (group III), a statistically significant (p = 0.013) decrease in HbA1c level by 0.2% after MLD therapy was demonstrated. Our results indicate that MLD may have a positive effect on selected biochemical parameters, with the most favorable changes in overweight patients. Further studies in a larger number of patients are warranted to confirm our findings, to test in-depth their mechanism, and to investigate clinical benefits of this alternative therapy in patients with abnormal body mass index.

Metabolic associated fatty liver disease is a disease related to sympathetic nervous system activation

Strong evidence from animal and human studies shows that sympathetic nervous system (SNS) activation is a key factor in the development of metabolic associated fatty liver disease (MAFLD). Activation of the sympathetic nervous system plays an important role in the pathogenesis of obesity, metabolic syndrome, diabetes, hypertension, and MAFLD. When genetically susceptible subjects are exposed to a variety of epigenetic changes, their liver damage may develop into MAFLD. Thus, the pathogenesis of MAFLD is complex, involving the complex interaction of insulin resistance, abnormal hormone secretion, obesity, diet, genetic factors, immune activation, gut microbiota, and other factors. In these processes, the role of sympathetic nerves cannot be underestimated. Notably, SNS has been proposed as a therapeutic target for MAFLD by inhibiting sympathetic nerves. It is worthy of further discussion and research.

Females with Diabetes Mellitus Increased the Incidence of Premenstrual Syndrome

Background: Premenstrual syndrome (PMS) is a multifactorial disorder caused by hormone and autonomic imbalance. In our study, hyperglycemia-induced insulin secretion increased progesterone secretion and progressive autonomic imbalance. The young patients with diabetes mellitus (DM) revealed hypo-parasympathetic function and hypersympathetic function compared with nondiabetic controls. Young female patients with DM with higher blood sugar and autonomic malfunction may be associated with PMS. However, there is a lack of evidence about DM in females related to PMS. We evaluated female patients with DM who subsequently followed PMS in a retrospective cohort study. Methods: We retrieved data from the National Health Insurance Research Database in Taiwan. Female patients with DM between 20 and 50 years old were assessed by the International Classification of Disease, 9 Revision, Clinical Modification (ICD-9-CM) disease code of 250. Patients who were DM-free females were fourfold matched to the control group by age and disease index date. The ICD-9-CM disease code of 625.4 identified the incidence of PMS followed by the index date as events. The possible risk factors associated with PMS were detected with a Cox proportional regression. Results: DM was a significant risk factor for PMS incidence with an adjusted hazard ratio of 1.683 (95% confidence interval: 1.104−2.124, p < 0.001) in females after adjusting for age, other comorbidities, season, urbanization status of patients and the hospital status of visiting. Conclusions: This study noted an association between DM and PMS in female patients. Healthcare providers and female patients with DM must be aware of possible complications of PMS, aggressive glycemic control, decreased hyperglycemia and autonomic dysfunction to prevent this bothersome disorder.

Deep transcranial magnetic stimulation in combination with skin thermography in obesity: a window on sympathetic nervous system

AIMS

Obesity is known to be associated with an altered thermoregulation as well as a dysregulation of sympathetic nervous system (SNS). Considering the ability of deep transcranial magnetic stimulation (dTMS) to modulate the SNS, we hypothesized a potential role of dTMS in affecting thermoregulation in obesity. Aims of the study were to monitor the effect of a single session of dTMS on body temperature in subjects with obesity, and to correlate the dTMS-induced changes in body temperature with activation of the SNS (epinephrine and norepinephrine release).

METHODS

Twenty-nine subjects with obesity [5 M, 24 F; age 50 (IQR: 58, 38) yrs; BMI 36.1 (IQR: 33.9, 38.7) kg/m²] were randomized into 2 groups receiving a single session of high frequency stimulation (HF) or sham stimulation. Under neutral thermal conditions, infrared thermography was utilized to assess bilateral fingernail-beds and abdominal temperature.

RESULTS

During a single session HF, the average temperature of both fingernail-beds decreased. Right-hand temperature difference was statistically greater in HF vs Sham: median = - 1.45 (IQR: - 2.0, - 1.0)  °C for HF, p = 0.009. While temperature variation in the fingernail-bed of left hand was not statistically significant in HF compared to Sham: median = - 1.26 (IQR: - 1.6, -0.5) °C, p = 0.064. Concurrently, when estimating the effect of norepinephrine variation on temperature change of fingernail-bed of left hand, a borderline significant positive association was estimated (beta = 1.09, p = 0.067) in HF.

CONCLUSIONS

Deep TMS revealed to be effective in modulating temperature in subjects with obesity, partially reversing obesity-induced alterations in heat production and dissipation with a potential SNS-mediated mechanism.

Sleep duration predicts subsequent long-term mortality in patients with type 2 diabetes: a large single-center cohort study

Background

Sleep duration is associated with mortality. However, prior studies exploring whether sleep duration predicts subsequent long-term mortality in patients with diabetes are limited. This study aims to examine whether metabolic factors affect the associations between baseline sleep duration and subsequent risks of all-cause, expanded, and non-expanded cardiovascular disease (CVD) mortalities among patients with type 2 diabetes (T2D).

Methods

A total of 12,526 T2D patients aged 30 years and older, with a follow-up period ≥ 3 years, were identified from the Diabetes Case Management Program of a medical center in Taiwan. Sleep duration was measured using computerized questionnaires by case managers, and the time frame for this question was 1 month prior to the interview date. Sleep duration in relation to subsequent mortality from all causes, expanded CVD, and non-expanded CVD was examined using Cox proportional hazard models.

Results

Within 10 years of follow-up, 2918 deaths (1328 CVD deaths and 1590 non-CVD deaths) were recorded. A J-shaped association was observed for all-cause, expanded CVD, and non-expanded CVD mortalities, and the lowest risks were observed for patients with 5–7 h of sleep. The significant joint effects included sleep duration of more or less than 7 h with age ≥ 65 years [adjusted HRs: 4.00 (3.49–4.60)], diabetes duration ≥ 5 years [1.60 (1.40–1.84)], age at diabetes diagnosis ≤ 45 years [1.69 (1.38–2.07)], insulin use [1.76 (1.54–2.03)], systolic blood pressure/diastolic blood pressure > 130/85 mmHg [1.24 (1.07–1.43)], triglyceride ≥ 150 mg/dL [1.38 (1.22–1.56)], HbA1c ≥ 7% [1.31 (1.13–1.52)], and body mass index < 27 kg/m² [1.31 (1.17–1.45)] for all-cause mortality.

Conclusion

A J-shaped association was observed between sleep duration and all-cause and expanded CVD mortality, and a sleep duration of 5–7 h had the lowest mortality risk. Sleep duration also showed significant synergistic interactions with diabetes duration but shared an antagonistic interaction with age and obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01500-0.

Closed-Loop Vagus Nerve Stimulation for the Treatment of Cardiovascular Diseases: State of the Art and Future Directions

The autonomic nervous system exerts a fine beat-to-beat regulation of cardiovascular functions and is consequently involved in the onset and progression of many cardiovascular diseases (CVDs). Selective neuromodulation of the brain-heart axis with advanced neurotechnologies is an emerging approach to corroborate CVDs treatment when classical pharmacological agents show limited effectiveness. The vagus nerve is a major component of the cardiac neuroaxis, and vagus nerve stimulation (VNS) is a promising application to restore autonomic function under various pathological conditions. VNS has led to encouraging results in animal models of CVDs, but its translation to clinical practice has not been equally successful, calling for more investigation to optimize this technique. Herein we reviewed the state of the art of VNS for CVDs and discuss avenues for therapeutic optimization. Firstly, we provided a succinct description of cardiac vagal innervation anatomy and physiology and principles of VNS. Then, we examined the main clinical applications of VNS in CVDs and the related open challenges. Finally, we presented preclinical studies that aim at overcoming VNS limitations through optimization of anatomical targets, development of novel neural interface technologies, and design of efficient VNS closed-loop protocols.

Cardiovascular autonomic reflex tests and serum FGF21 levels in overweight and normal-weight men and women

OBJECTIVE

We evaluated cardiovascular autonomic reflexes and serum fibroblast growth factor 21 (FGF21), a surrogate marker of mitochondrial function, in a cohort of overweight and normal-weight adults (n = 42).

METHODS

Indices of autonomic function were monitored during supine rest, autonomic reflex tests and submaximal clinical exercise test, with heart rate variables and blood pressure measured with an automatic system.

RESULTS

Markers of sympathetic dominance were accentuated in overweight adults, including elevated resting low-frequency to the high-frequency ratio for heart rate variability (203 ± 227 vs. 96 ± 42; p = .01), and handgrip diastolic blood pressure (36 ± 15 mmHg vs. 25 ± 12 mmHg; p = .01). A weak non-significant trend has been found for a negative correlation between blood pressure responses to isometric handgrip test and FGF21 in the overweight group (r = -0.37; p = .09).

CONCLUSIONS

Excess body weight appears to trigger sympathetic overactivity in overweight adults, yet autonomic dysregulation might not be associated with notable changes in serum FGF21.

Neurohormonal Changes in the Gut–Brain Axis and Underlying Neuroendocrine Mechanisms following Bariatric Surgery

Obesity is a complex, multifactorial disease that is a major public health issue worldwide. Currently approved anti-obesity medications and lifestyle interventions lack the efficacy and durability needed to combat obesity, especially in individuals with more severe forms or coexisting metabolic disorders, such as poorly controlled type 2 diabetes. Bariatric surgery is considered an effective therapeutic modality with sustained weight loss and metabolic benefits. Numerous genetic and environmental factors have been associated with the pathogenesis of obesity, while cumulative evidence has highlighted the gut–brain axis as a complex bidirectional communication axis that plays a crucial role in energy homeostasis. This has led to increased research on the roles of neuroendocrine signaling pathways and various gastrointestinal peptides as key mediators of the beneficial effects following weight-loss surgery. The accumulate evidence suggests that the development of gut-peptide-based agents can mimic the effects of bariatric surgery and thus is a highly promising treatment strategy that could be explored in future research. This article aims to elucidate the potential underlying neuroendocrine mechanisms of the gut–brain axis and comprehensively review the observed changes of gut hormones associated with bariatric surgery. Moreover, the emerging role of post-bariatric gut microbiota modulation is briefly discussed.