Relation between heart rate variability and spectral analysis of electroencephalogram in chronic neuropathic pain patients.

Chronic neuropathic pain (CNP) is a complex condition often arising from neural maladaptation after nerve injury. Understanding CNP complications involves the intricate interplay between brain-heart dynamics, assessed through quantitative electroencephalogram (qEEG) and heart rate variability (HRV). However, insights into their interaction in chronic pain are limited. Resting EEG and simultaneous electrocardiogram (lead II) of the participants were recorded for qEEG and HRV analysis. Correlations between HRV and qEEG parameters were calculated and compared with age, sex, and body mass index (BMI)-matched controls. CNP patients showed reduced HRV and significant increases in qEEG power spectral densities within delta, theta, and beta frequency ranges. A positive correlation was found between low frequency/ high frequency (LF/HF) ratio in HRV analysis and theta, alpha, and beta frequency bands in qEEG among CNP patients. However, no significant correlation was observed between parasympathetic indices and theta, beta bands in qEEG within CNP group, unlike age, sex, and BMI-matched healthy controls. CNP patients display significant HRV reductions and distinctive qEEG patterns. While healthy controls exhibit significant correlations between parasympathetic HRV parameters and qEEG spectral densities, these relationships are diminished or absent in CNP individuals. LF/HF ratio, reflecting sympathovagal balance, correlates significantly with qEEG frequency bands (theta, alpha, beta), illuminating autonomic dysregulation in CNP. These findings emphasize the intricate brain-heart interplay in chronic pain, warranting further exploration.

Correlation among Poincare plot and traditional heart rate variability indices in adults with different risk levels of metabolic syndrome: a cross-sectional approach from Southern India.

OBJECTIVES: Heart rate variability (HRV) is an important marker of cardiac autonomic modulation. Metabolic syndrome (MetS) can alter cardiac autonomic modulation, raising the risk of cardiovascular disease (CVD). Poincaré plot analysis (PPA) is a robust scatter plot-based depiction of HRV and carries similar information to the traditional HRV measures. However, no prior studies have examined the relationship between PPA and traditional HRV measures among different risk levels of MetS. We evaluated the association between the Poincare plot and traditional heart rate variability indices among adults with different risk levels of MetS. METHODS: We measured anthropometric data and collected fasting blood samples to diagnose MetS. The MetS risk was assessed in 223 participants based on the number of MetS components and was classified as control (n=64), pre-MetS (n=49), MetS (n=56), and severe MetS (n=54). We calculated the Poincaré plot (PP) and traditional HRV measures from a 5 min HRV recording. RESULTS: Besides the traditional HRV measures, we found that various HRV indices of PPA showed significant differences among the groups. The severe MetS group had significantly lower S (total HRV), SD1 (short-term HRV), SD2 (long-term HRV), and higher SD2/SD1. The values of S, SD1, SD2, and SD2/SD1 were significantly correlated with most traditional HRV measures. CONCLUSIONS: We found gradual changes in HRV patterns as lower parasympathetic and higher sympathetic activity alongside the rising number of MetS components. The HRV indices of PPA integrating the benefits of traditional HRV indices distinguish successfully between different risk levels of MetS and control subjects.

Association between metabolic syndrome components and cardiac autonomic modulation in southern Indian adults with pre-metabolic syndrome: hyperglycemia is the major contributing factor.

Metabolic syndrome (MetS) involves multi-factorial conditions linked to an elevated risk of type 2 diabetes mellitus and cardiovascular disease. Pre-metabolic syndrome (pre-MetS) possesses two MetS components but does not meet the MetS diagnostic criteria. Although cardiac autonomic derangements are evident in MetS, there is little information on their status in pre-MetS subjects. In this study, we sought to examine cardiac autonomic functions in pre-MetS and to determine which MetS component is more responsible for impaired cardiac autonomic functions. A total of 182 subjects were recruited and divided into healthy controls (n=89) and pre-MetS subjects (n=93) based on inclusion and exclusion criteria. We performed biochemical profiles on fasting blood samples to detect pre-MetS. Using standardized protocols, we evaluated anthropometric data, body composition, baroreflex sensitivity (BRS), heart rate variability (HRV), and autonomic function tests (AFTs). We further examined these parameters in pre-MetS subjects for each MetS component. Compared to healthy controls, we observed a significant cardiac autonomic dysfunction (CAD) through reduced BRS, lower overall HRV, and altered AFT parameters in pre-MetS subjects, accompanied by markedly varied anthropometric, clinical and biochemical parameters. Furthermore, all examined BRS, HRV, and AFT parameters exhibited an abnormal trend and significant correlation toward hyperglycemia. This study demonstrates CAD in pre-MetS subjects with reduced BRS, lower overall HRV, and altered AFT parameters. Hyperglycemia was considered an independent determinant of alterations in all the examined BRS, HRV, and AFT parameters. Thus, hyperglycemia may contribute to CAD in pre-MetS subjects before progressing to MetS.

Cut-off values and clinical efficacy of body roundness index and other novel anthropometric indices in identifying metabolic syndrome and its components among Southern-Indian adults.

CONTEXT: Abdominal obesity (AO) is a definitive link between cardiometabolic complications and metabolic syndrome (MetS). Many traditional and novel anthropometric indices have been identified to determine AO, and their relationship to MetS has been investigated. However, whether these indices are useful in a clinical setting is unknown. Moreover, the cut-off points for these indices to determine MetS have yet to be defined among Southern-Indian adults. AIMS: We aimed to evaluate the cut-off values and clinical efficacy of novel anthropometric indices in identifying MetS and its components. MATERIALS AND METHODS: Subjects (n = 202) were recruited and then grouped into cases (MetS = 106) and controls (healthy = 96). We measured anthropometric data and assayed glycemic and lipid profiles. Using these, we computed a-body shape index (ABSI), abdominal volume index (AVI), body adiposity index (BAI), body roundness index (BRI), conicity index (CI), lipid-accumulation product (LAP), visceral adiposity index (VAI) and waist-triglyceride index (WTI) from published equations. RESULTS: Compared to the control group, all the novel anthropometric indices were noticeably higher in both male and female subjects of the MetS group. The area under the curve values (AUCs) demonstrated that BRI, CI, AVI, and WTI had superior detection power in identifying MetS, and the AUCs varied upon stratification by gender. BRI was strongly associated with the highest odds of having MetS (OR 66.03). CONCLUSIONS: The optimal cut-off and AUC values attained for BRI, CI, AVI, and WTI have a clinical approach in identifying MetS and its components. The efficacy of these indices to identify MetS differed by gender.

Relationship between advanced glycated end products and maternal cognition in gestational diabetes: a case control study.

OBJECTIVE: Gestational diabetes (GDM) is a form of glucose intolerance which manifests during pregnancy. There is lack of literature regarding the study of cognitive functions in GDM. Recent evidences suggests an increase in accumulation of serum Advanced glycated end products (AGE'S) during GDM. Accumulation of AGE's in brain can induce changes in permeability of blood brain barrier and creates oxidative stress and inflammation that can alter cognitive functions. In this study we hypothesize that diagnosis of GDM in pregnancy is related to lower cognitive scores which is correlated to increased serum AGE's level. METHOD: This was a cross sectional case control study which recruited 60 participants in total consisting of two groups with 30 participants in each - diagnosed cases of GDM and healthy pregnant controls. Subjects were recruited from OPD of Obstetrics & Gynecology department in a tertiary care hospital in South India at gestational age of 32-36 weeks. On the first appointment, biochemical parameters of Fasting plasma glucose (FPG) & HbA1C was measured in both groups. Serum was obtained for testing levels of N Carboxy methyl lysine (N-CML) (a form of AGE). On second appointment, pen and paper neurocognitive tests including Montreal cognitive tests (MOCA) and Trail making test (TMT A & B) was presented. Event related potentials (ERP's) are time locked EEG wave signals produced in response to a sensory, motor or cognitive event. P300 is an "endogenous" ERP produced by cognitive processing in response to a stimuli presented to subject. P300 wave Latency and amplitude was recorded in both the groups as an objective marker of cognitive processing. Above mentioned biochemical and neurocognitive parameters were compared between both the groups and correlation analysis between serum AGE levels and neurocognitive parameters was performed using SPSS software. RESULTS: Biochemical parameters of HbAIC & N-CML(A form of AGE) levels were increased in GDM group (HbA1C 6.01±0.30 and N CML 236.25 ± 68.9) vs Control group (HbA1C 4.11 ± 0.68 and NCML 198.42 ± 44.2). Scores in MOCA were significantly lower in GDM (28 (27-29)) group as compared to controls (24 (23-25)). GDM subjects took significantly greater time to perform TMT A (24.59 ± 2.60 s) test than controls (29.7 ± 1.72 s). Significant changes were not found in P300 Latency & amplitude in GDM group. Decreased MOCA scores and increased duration of TMT A attempt were correlated with increased serum AGE concentration in GDM group. CONCLUSIONS: Our study indicates the vulnerability of women suffering from GDM to cognitive impairment during pregnancy. Lower scores in cognitive tests were correlated to AGE accumulation in GDM women.

Association of Circulating Brain-Derived Neurotrophic Factor with Cognition among Adult Obese Population.

BACKGROUND: Obesity has a strong association with the risk of developing cognitive impairment and dementia at a later age. Brain-derived neurotrophic factor (BDNF) and its receptor appear to be important components in cognitive function and are also involved in energy homeostasis. The level of circulating BDNF and its association with cognition has yet to be delineated clearly. In this work we studied the association of circulating BDNF with cognition among the adult obese population. METHODS: The study involved 132 healthy participants between 18 and 40 years of age and of both sexes. The participants were categorized into an obesity group (n=66) and a non-obese group (n=66) based on their body mass index (Asian criteria). The level of cognitive performance was assessed by the event-related potentials P300 (ERPs-P300), mini-mental state examination (MMSE), both visual and auditory reaction times (VRT and ART, respectively), and other pen and paper tests related to memory and executive function. Serum BDNF, glycemic and lipid profiles were estimated. RESULTS: We found significant differences in the ERPs-P300 latency (P<0.001) and amplitude (P=0.002) between the non-obese and obese group. The MMSE score was significantly reduced while VRT (P=0.005) and ART (P=0.001) were larger in the obese group. BDNF levels (P<0.001) were significantly reduced and negatively associated with the obese group. ERPs-P300 latency was negatively associated (r=-0.674, P=0.001) whereas amplitude (r=0.507, P<0.001) was positively associated with the BDNF levels in the adult obese population. CONCLUSION: We found reduced circulating BDNF levels in obese adults and that lower BDNF levels were strongly associated with cognitive decline in the obese adult population.

Effect of honey and insulin treatment on oxidative stress and nerve conduction in an experimental model of diabetic neuropathy Wistar rats.

Diabetic neuropathy is the most common complication affecting more than 50% of patients with longstanding diabetes. Till date, there are no reports to explain the scientific basis of alternative medicine as an adjunct therapy for treating diabetic neuropathy. Hence, we studied the effect of honey and insulin treatment on hyperglycemia, dyslipidemia, oxidant and anti-oxidant status and nerve conduction in experimental diabetic neuropathy Wistar rats. In this experimental study, forty healthy male Wistar albino rats of 10-12 weeks age, weighing between 150 to 200g were obtained from our institute central animal house. After acclimatization, the rats were divided into control (n = 8) and experimental (n = 32) groups randomly. In the experimental group, type 2 diabetic neuropathy was induced with high fat and high sugar diet for 8 weeks followed by streptozotocin at a dose of 35 mg/kg body weight. Three days after streptozotocin injection, blood glucose levels of rats were measured from fasting samples to confirm diabetes. After the development of diabetes, rats were given standard rodent chow and allowed four more weeks to remain diabetic and to develop neuropathy. Every second week, nerve conduction study was done to confirm neuropathy. All the diabetic rats of experimental group developed neuropathy after 4 weeks of developing diabetes, which was confirmed by significant reduction in conduction velocity of sensory and motor nerve when compared to non-diabetic control group. After the development of neuropathy, these rats were randomly divided into diabetic neuropathy with no treatment group (n = 8) and three treatment groups (n = 8, each). The rats of treatment group were administered with either honey or insulin or honey+insulin for six weeks. After six-weeks of intervention, there was significant decrease in blood glucose and lipids in honey, insulin and honey+insulin treated neuropathy rats, when compared with no treatment group. Malondialdehyde was reduced and total anti-oxidant status improved in all the three treatment groups. There was no significant increase in conduction velocity of sciatic tibial motor nerve in treatment groups when compared with no treatment group. However, the sensory nerve conduction velocity improved significantly in honey+insulin treated neuropathy rats. In conclusion, six-week honey treatment helped in reducing dyslipidemia and oxidative stress. Honey given along with insulin for six-weeks improved sensory nerve conduction velocity in experimental diabetic neuropathy Wistar rats.

Cut-off Values and Clinical Utility of Surrogate Markers for Insulin Resistance and Beta-Cell Function to Identify Metabolic Syndrome and Its Components among Southern Indian Adults.

BACKGROUND: Insulin resistance (IR) is a collective clinical entity that exacerbates metabolic syndrome (MetS). As the gold-standard test to quantify IR involves intravenous insulin loading and repeated blood glucose monitoring, many indices have been developed for IR assessment for convenience. This study tested the ideal cut-off values and clinical utility of IR indices in identifying MetS. METHODS: We recruited 150 subjects, 75 MetS patients and 75 healthy controls, then obtained written informed consent to participate in this study. We collected fasting blood samples for glucose and lipid profiles and calculated nineteen indices of IR and insulin secretion using validated formulae. We determined the precision of these IR indices using the area under the curve (AUC) in a receiver operating characteristic analysis. RESULTS: Subjects with MetS have significantly higher IR coupled with lower insulin sensitivity and beta-cell function than controls. Among the surrogate markers of IR tested, the homeostatic model assessment of insulin resistance (HOMA-IR), HOMA-adiponectin (HOMA-AD), triglyceride-glucose (TyG) index, HOMA-1%S (insulin sensitivity), quantitative insulin sensitivity check index (QUICKI), McAuley index, single-point insulin sensitivity estimator (SPISE), and HOMA-2%B (beta-cell function) showed the highest AUC values for detecting MetS. CONCLUSION: Our study results suggest that the ideal cut-off and AUC values identified for HOMA-IR, HOMA-AD, the TyG index, HOMA-1%S, QUICKI, the McAuley index, SPISE, and HOMA-2%B offer a clinical approach to the early detection and risk stratification for MetS among people in southern India.

Impaired baroreflex sensitivity and cardiac autonomic functions are associated with cardiovascular disease risk factors among patients with metabolic syndrome in a tertiary care teaching hospital of South-India.

BACKGROUND & AIM: Baroreflex sensitivity (BRS) and heart rate variability (HRV) have been proposed to assess early autonomic dysfunction in metabolic syndrome (MetS) patients. Autonomic dysfunction in MetS patients may increase the risk of developing cardiovascular disease (CVD). However, the association of BRS and HRV with CVD risk factors remains elusive in MetS. The primary aim of this study was to assess the BRS and HRV in MetS patients among South-Indian adults and check whether BRS and HRV are associated with CVD risk factors. METHODS: We performed anthropometric indices, body composition, physiological parameters such as BRS, HRV, and other autonomic function tests in 176 subjects divided into MetS patients (n = 88) and healthy controls (n = 88). Fasting blood samples were collected for biochemical profiles and calculated insulin resistance indices, atherogenic index (AI), and rate pressure product (RPP). RESULTS: When compared to controls, we found significantly reduced BRS and an increased ratio of low-frequency (LF) to high-frequency (HF) power of HRV (LF/HF) in the MetS group. We observed significant differences in body composition and biochemical profiles among the MetS group. BRS and LF/HF ratio of HRV have shown a significant association with CVD risk factors in the MetS group. CONCLUSIONS: We observed autonomic dysfunction as low BRS and high LF/HF ratio of HRV in MetS patients. Additionally, the present results emphasize that the association of BRS and LF/HF ratio with anthropometric, glucose, lipid parameters, and other CVD risk factors may increase the susceptibility of MetS patients to higher CVD risk.

Effect of Yoga Therapy on Disease Activity, Inflammatory Markers, and Heart Rate Variability in Patients with Rheumatoid Arthritis.

Background: Rheumatoid arthritis (RA) is an immune-mediated inflammatory disease. Antirheumatoid treatment reduces disease activity and inflammation, but not all patients respond to treatment. Autonomic dysfunction is common in RA leading to frequent cardiovascular complications. Yoga therapy may be useful in these patients, but there are little data on the effect of yoga on disease activity, inflammatory markers, and heart rate variability (HRV). Objectives: This study assessed the effect of 12-week yoga therapy on disease activity, inflammatory markers, and HRV in patients with RA. Materials and Methods: This randomized control trial was conducted on newly diagnosed RA patients attending outpatient services at the Department of Clinical Immunology, JIPMER. One hundred and sixty-six participants were randomized into two groups: the control group (CG) (n = 83) and yoga group (YG) (n = 83). Yoga therapy was administered to participants in the YG for 12 weeks, along with standard medical treatment. The CG received only standard medical treatment. Primary outcomes were disease activity score 28, interleukin-1α (IL-1α), IL-6, tumor necrosis factor-α (TNF-α), cortisol, and HRV parameters. All parameters were measured at baseline and after 12 weeks. Results: Disease activity significantly decreased in both groups after 12 weeks, but it was reduced more in YG, which was statistically significant (p < 0.05). In both YG and CG, IL-1α, IL-6, TNF-α, and cortisol decreased after 12 weeks, but IL-1α and cortisol decreased more significantly in YG than in CG. Low-frequency component expressed as normalized unit (LFnu) and the low-frequency/high-frequency (LF-HF) ratio decreased significantly, and total power and HF component expressed as normalized unit (HFnu) increased significantly in the YG compared with CG. Conclusion: Twelve-week yoga therapy, if given along with standard medical treatment, significantly reduces disease activity and improves sympathovagal balance in RA patients.

Effect of slow and fast pranayama training on handgrip strength and endurance in healthy volunteers.

BACKGROUND: Pranayama has been assigned very important role in yogic system of exercises and is said to be much more important than yogasanas for keeping sound health. Also different pranayamas produce divergent physiological effects. AIM: To study the effect of 12 weeks training of slow and fast pranayama on handgrip strength and endurance in young, healthy volunteers of JIPMER population. SETTINGS AND DESIGN: Present study was conducted in the Department of Physiology, JIPMER in 2011-12 (1.06.11 to 1.04.12). MATERIALS AND METHODS: Total of 91 volunteer subjects were randomised into slow pranayama (SPG) (n=29), fast pranayama (FPG) (n=32) and control groups (CG) (n=30). Supervised pranayama training (SPG - Nadisodhana, Pranav pranayama and Savitri pranayama; FPG - Kapalabhati, Bhastrika and Kukkuriya pranayama) was given for 30 minutes thrice a week for 12 weeks to both slow and fast pranayama groups by certified yoga trainer. Hand grip strength (HGS) and endurance (HGE) parameters were recorded using handgrip dynamometer (Rolex, India) at baseline and after 12 weeks of pranayama training. STATISTICAL ANALYSIS USED: Longitudinal changes in each group were compared by using Student's paired t-test. Delta changes in each group were analysed by ANOVA with Tukey post-hoc analysis. RESULTS: In SPG significant improvement occurred only in HGE parameter from 83.95±45.06 to 101.62±53.87 (seconds) (p<0.001) whereas in FPG, significant improvement was observed in HGS from 33.31±9.83 to 37.9±9.41 (Kilograms) (p=0.01) as well as in HGE from 92.78±41.37 to 116.56±58.54 (seconds) (p=0.004). Using Students unpaired t-test difference between the groups in HGS is found to be 1.17±5.485 in SPG and in FPG is 4.59±7.26 (p=0.39); HGE difference in SPG is 1.77±21.17 and in FPG is 2.38±43.27 (p>0.05). CONCLUSION: Pranayama training decreases sympathetic activity, resulting in mental relaxation and decreased autonomic arousal thereby, decreasing force fluctuations during isometric contraction. This is reflected as improvement in HGS and HGE.