Comparison of cardiac autonomic function across complete glycaemic spectrum.

OBJECTIVES: Autonomic imbalance is attributed as key mechanism altering metabolic regulation in diabetes mellitus. In view of controversial reports on autonomic function in FDRD and prediabetes, we aimed to assess and compare the autonomic function across the complete glycaemic spectrum in Indian population. METHODS: Short term heart rate variability and cardiac autonomic reactivity tests - blood pressure and heart rate response to orthostatic tolerance and deep breathing exercise, and diastolic response to isometric handgrip exercise were recorded in normoglycemic apparently healthy individual, normoglycemic first degree relatives of diabetes, prediabetes and diabetes individuals. RESULTS: Resting heart rate is significantly higher in FDRD, prediabetes and diabetes as compared to controls (control < FDRD = prediabetes = diabetes). Total power, LF power (control < FDRD < prediabetes = diabetes) and HF power (control < FDRD < prediabetes < diabetes) decreased along the glycaemic spectrum. Time-domain variables of HRV (SDNN, RMSSD, NN50, pNN50) were reduced as we move along the glycaemic spectrum (control < FDRD < prediabetes = diabetes). Cardiac autonomic function reactivity parameters such as 30:15 ratio and E:I ratio are decreased in prediabetes and diabetes group as compared to control and FDRD group (control = FDRD < prediabetes = diabetes). Diastolic response to isometric hand grip increases along the glycaemic spectrum starting from FDRD (control < FDRD < prediabetes = diabetes). CONCLUSIONS: Autonomic dysfunction is observed even in first degree relatives of diabetes. Autonomic dysfunction increases as we move along the glycaemic spectrum (control < FDRD < prediabetes < diabetes).

Effect of 4-Week Heartfulness Meditation on Stress Scores, Sleep Quality, and Oxidative and Inflammatory Biochemical Parameters in COVID-19 Patients after Completion of Standard Treatment - A Randomized Controlled Trial.

Context: COVID-19-affected patients showed increased stress, impaired sleep quality, altered complete blood count, and increased inflammatory and oxidative parameters. Yoga is an add-on nonpharmacological treatment that is established to normalize the abovementioned parameters. Heartfulness meditation is a form of Raja yoga. Aims: The present study aimed to study the effects of 4 weeks of heartfulness meditation on the abovementioned parameters in COVID-19 patients following treatment completion. Settings and Design: The present study was a randomized controlled trial carried out in the Department of Physiology, AIIMS, Mangalagiri, Andhra Pradesh. Subjects and Methods: Out of 50 COVID-19 treatment-completed patients recruited for the study, 25 were randomly assigned to the study group who received 4-week app-based heartfulness meditation. Other 25 patients were assigned to the control group who received app-based relaxation for 4 weeks. Perceived stress score, Pittsburgh Sleep Quality Index questionnaire, baseline cardiovascular parameters, complete blood count, serum cortisol, inflammatory parameters, oxidative stress parameters, and antioxidant parameters were assessed before and after 4 weeks of intervention in both the groups. The outcome assessor was blinded in the present study. Statistical Analysis Used: The mean difference between the two groups was tested using the Student's t-test or Mann-Whitney U-test based on data distribution. Effect of intervention was analyzed using paired Student's t-test for dependent samples test or Wilcoxon signed-rank test based on data distribution. Results: The groups were comparable before intervention for all the variables. After 4 weeks of intervention, we observed a significant decrease in stress, circulating cortisol, inflammatory markers, and oxidative stress biomarker in both the groups. Further, we observed improved sleep quality and antioxidant biomarkers in both the groups. These beneficial alterations following intervention were high in the study group compared to the control group. Conclusions: Our results suggest that app-based heartfulness meditation/relaxation can be used as a nonpharmacological adjuvant to hasten the recovery process in patients who have completed the COVID-19 treatment protocol. Beneficial effects in subjects practicing heartfulness meditation were more than that observed in subjects practicing relaxation.

Assessment of vascular function in complete glycaemic spectrum.

Purpose: The present study was conceived to delineate the point of vascular dysfunction along the glycemic spectrum (normoglycemic individuals with no family history of diabetes, normoglycemic individuals with family history of diabetes, prediabetic individuals, and diabetic individuals).Materials and Methods: In this cross-sectional comparative study, we enrolled 252 participants of both gender in the age group of 30-50 years. They were classified based on their family history of diabetes and glycemic status into four groups along the glycemic spectrum as mentioned above. We measured flow-mediated dilation (FMD) from brachial artery and vascular function biomarkers such as enthothelin-1 (ET-1), von Willbrand Factor (vWF), Vascular Endothelial Growth Factor (VEGF) to assess the vascular function. The comparison of data between groups were done using One Way ANOVA/Kruskal-Wallis followed by post-hoc analysis using LSD/Mann-Whitney U Test depending on the normality of the data. Spearman correlation was done between vascular function and plasma glucose levels to identify its relationship. Linear regression was carried out to identify the factors influencing the FMD across the glycemic spectrum.Results: We observed that vascular function negatively correlated with blood glucose levels. However, endothelin-1 and vWF derangement was there even in normoglycemic first degree relatives of diabetes (FDRD) and the derangement increased in prediabetes and diabetes. Physiological dysfunction in terms of decreased flow-mediated dilation starts from prediabetes only. VEGF derangement is found only in diabetic individuals.Conclusion: Vascular dysfunction is found even in normoglycemic FDRD and the derangement increased and compounded with the advancement of disease.

Comparison of Baroreflex Sensitivity and Cardiac Autonomic Function Between Adolescent Athlete and Non-athlete Boys - A Cross-Sectional Study.

Introduction: It is well known that regular physical activity improves cardiovascular health, and higher baroreflex sensitivity and heart rate variability are associated with cardiovascular health. Adolescence is the age when an individual's behavior is easily modified; early intervention at this stage in terms of physical conditioning or training prevents future cardiovascular risk. Hence, we conceived the present study to assess and compare the baroreflex sensitivity and autonomic function between adolescent athletes and non-athletes. Methods: We recruited school going athletes (n = 30) and non-athlete boys (n = 30) in the 10-19 age group after obtaining their assent and consent from their parents. We assessed height, weight, heart rate, blood pressure, baroreflex sensitivity, and cardiac autonomic function. Comparison between groups was made using the unpaired t-test for height, weight, body mass index, heart rate, blood pressure, and baroreflex sensitivity and using Mann-Whitney U test for cardiac autonomic function parameters. Results: There was a trend for higher baroreflex sensitivity in athletes. Heart rate variability (total power and SDNN) was higher in athletes. The parasympathetic tone was higher in terms of higher RMSSD, and higher HF power. Parasympathetic reactivity was higher in athletes in terms of higher 30:15 ratio and EI ratio. Conclusion: Athletic level physical conditioning has a positive influence on baroreflex function and autonomic function that may prove beneficial to the adolescents' cardiovascular health.

Assessment of autonomic functions and its association with telomerase level, oxidative stress and inflammation in complete glycemic spectrum- an exploratory study.

AIMS: In the present study we intended to study autonomic functions and its association with telomerase level, oxidative stress and inflammation in complete glycemic spectrum. MATERIALS AND METHODS: Age, gender and BMI matched 28 subjects in the age group of 25-50 years were recruited across complete glycemic spectrum as follows: 1) Normoglycemics (controls) 2) Prediabetics and 3) Frank diabetics. We assessed heart rate variability, cardiac autonomic function, lipid profile, adiponectin, malondialdehyde and telomerase level. RESULTS: Time domain parameters and frequency domain parameters were significantly lower, and LFnu and LF/HF ratio were significantly higher in prediabetes and diabetes than control. Serum Adiponectin and HDL levels were significantly lower in diabetes than prediabetes and control, and prediabetes had significantly lower HDL than controls. Other lipid profile parameters (TC, TG, VLDL, LDL, non-HDL & derived lipid parameters were significantly higher in diabetes than prediabetes and control and prediabetes had significantly higher values than controls. MDA levels were significantly higher and TAS was significantly lower in diabetics than prediabetics and control group. Telomerase level was significantly higher in diabetes as compared to prediabetes and control. Telomerase had significantly negative correlation with SDNN, HF, TP, HDL and adiponectin, and significant positive correlation with MDA, fasting insulin, HOMA IR, TC, and AIP. CONCLUSION: Oxidative damage, inflammation and autonomic dysregulation may be involved in Telomere/Telomerase dysregulation in diabetes and telomerase levels can be used as a cardio-metabolic marker of diabetes.

Comparison of anthropometric, cardiovascular, autonomic, baroreflex sensitivity, aerobic fitness, inflammatory markers and oxidative stress parameters between first degree relatives of diabetes and controls.

AIM: We aimed at assessing cardiovascular risk of first degree relatives of diabetes (FDRD). METHODS: A cross sectional study involving 90 apparently healthy normoglycemic volunteers aged between 15 and 50 years (45 FDRD and 45 FDRs of non-diabetics). We measured anthropometric parameters, baroreflex sensitivity, heart rate variability, cardiac autonomic function tests, and aerobic capacity, fasting blood glucose and insulin, lipid profile, inflammatory markers, nitric oxide and oxidative stress markers. RESULTS: FDRD had significantly higher hip circumference and BF%. Blood pressure, total peripheral resistance and cardiac output were comparable. FDRD had higher HR and rate pressure product. There were no significant differences in cardio-respiratory fitness (VO2max) and physical activity level. Time and Frequency domain parameters were comparable except for reduced NN50 and total power. Baroreflex sensitivity, 30:15 ratio and E: I ratio were significantly less in FDRD. Fasting glucose was comparable. Fasting Insulin, HOMA IR, HOMA %B and HOMA AD were higher while HOMA %S and QUICKI index were lower in FDRD. Lipid profile or lipid derived parameters were comparable except for higher non-HDLc in FDRD. Adiponectin was lower while Leptin and Leptin/apidonectin ratio was higher in FDRD. IL-6, hsCRP, TNF- alpha and MDA were significantly higher in FDRD, while TAS and nitric oxide were significantly lower in FDRD. CONCLUSION: Higher body fat percentage, with insulin resistance, deranged cardiac autonomic function, higher oxidative stress and inflammation, lower adiponectin and nitric oxide levels places FDRD at higher cardiovascular risk and necessitates early lifestyle modification/intervention.

Comparison of cognitive auditory event related potentials and executive functions in adolescent athletes and non-athletes - A cross sectional study.

There is strong evidence for the positive physical health outcomes of physical conditioning (athletic training. But there is a dearth of data on the impact of exercise on cognition, particularly in the adolescent age group. Further, most of the studies done on this topic are mainly acute in nature, and few that have seen long term effect of exercise have very rarely used objective measures such as event-related potentials. Hence, the present study was conceived to compare cognition in athletes (individual who have undergone long term physical activity) and non-athletes. We designed a cross-sectional comparative study involving apparently healthy volunteer boys in the age group of 10-19 years-non-athletes (n = 30) and athletes (n = 30). Paper pencil tests such as letter cancellation test, auditory and visual recognition reaction time, trail making test (A and B) were recorded along with auditory event-related potentials (N100, P200, N200, and P300). Data were analyzed using an unpaired t-test and Mann-Whitney U test according to the data distribution. Athletes completed letter cancellation task and trail making test faster than non-athletes. Athletes visual and auditory reaction time were lesser. Athletes had reduced latency and higher amplitude of auditory event-related potentials (N100, P200, N200, and P300) as compared to non-athletes. Hence, we conclude that athletic level physical training has a beneficial role in the executive cognitive domain among adolescents.

Assessment of heart rate variability for different somatotype category among adolescents.

Background Somatotype is a quantified expression of the morphological conformation of a person in terms of three-numeral rating each representing one component; fat (endomorphy), muscle mass (mesomorphy) and bone length (ectomorphy) in the same order. Certain somatotypes are more prone to develop the particular disease. Obesity and overweight are already epidemic among Indian adolescents and are increasing at an alarming rate, and obesity is linked to cardiovascular (CV) risk in this age group. Identifying the heart rate variability (HRV) is an established non-invasive test to identify the CV risk. The objective of this study is to record the HRV data for each somatotype category and to compare the HRV data among these somatotype categories in adolescents. Methods The volunteer adolescents in the age group of 12-17 years were classified into a different somatotyping categories based on the Heath Carter somatotyping method. The short-term HRV was recorded in all the subjects using wireless BioHarness 3.0. Results Based on the time domain and frequency domain parameters, the parasympathetic activity showed decreasing order as follows: central>ectomorphy>mesomorphy>endomorphy, whereas sympathetic activity showed increasing order as follows: central

Comparison of structured and unstructured physical activity training on predicted VO2max and heart rate variability in adolescents - a randomized control trial.

BACKGROUND: Physical inactivity contributes to many health issues. The WHO-recommended physical activity for adolescents encompasses aerobic, resistance, and bone strengthening exercises aimed at achieving health-related physical fitness. Heart rate variability (HRV) and maximal aerobic capacity (VO2max) are considered as noninvasive measures of cardiovascular health. The objective of this study is to compare the effect of structured and unstructured physical training on maximal aerobic capacity and HRV among adolescents. METHODS: We designed a single blinded, parallel, randomized active-controlled trial (Registration No. CTRI/2013/08/003897) to compare the physiological effects of 6 months of globally recommended structured physical activity (SPA), with that of unstructured physical activity (USPA) in healthy school-going adolescents. We recruited 439 healthy student volunteers (boys: 250, girls: 189) in the age group of 12-17 years. Randomization across the groups was done using age and gender stratified randomization method, and the participants were divided into two groups: SPA (n=219, boys: 117, girls: 102) and USPA (n=220, boys: 119, girls: 101). Depending on their training status and gender the participants in both SPA and USPA groups were further subdivided into the following four sub-groups: SPA athlete boys (n=22) and girls (n=17), SPA nonathlete boys (n=95) and girls (n=85), USPA athlete boys (n=23) and girls (n=17), and USPA nonathlete boys (n=96) and girls (n=84). RESULTS: We recorded HRV, body fat%, and VO2 max using Rockport Walk Fitness test before and after the intervention. Maximum aerobic capacity and heart rate variability increased significantly while heart rate, systolic blood pressure, diastolic blood pressure, and body fat percentage decreased significantly after both SPA and USPA intervention. However, the improvement was more in SPA as compared to USPA. CONCLUSIONS: SPA is more beneficial for improving cardiorespiratory fitness, HRV, and reducing body fat percentage in terms of magnitude than USPA in adolescent individuals irrespective of their gender and sports activities.

Heart Rate Variability in Adolescents - Normative Data Stratified by Sex and Physical Activity.

BACKGROUND: Heart rate variability (HRV) refers to the beat-to-beat fluctuations in the cardiac rhythm occurring due to modulation of the pacemaker (sinoatrial node) activity of the heart by the sympathetic and parasympathetic branches of the autonomic nervous system. Nowadays, cardiovascular diseases and their risk factors are increasingly occurring at a younger age (children and adolescents) and recording of HRV in them will help us to identify cardiovascular autonomic derangement earlier. However, to be used clinically, normative data has to be established in this age group considering other major factors that can influence HRV such as sex, physical activity, and BMI. MATERIALS AND METHODS: Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology has provided the standards for measurement of heart rate variability and we have followed the same. In the present study, we have described the normative data for HRV in the adolescent in the age group of 12-17 years, stratified based on sex and physical activity. RESULTS: Data given below are expressed as median with interquartile range (Median (IQR)) in the following order: non-athlete girls, non athlete boys, athlete girls and athlete boys. Time domain indices - SDNN - 66.35 (40.78), 63.20 (36.20), 113.00 (31.40) and 94.20 (35.55); RMSSD - 69.00 (50.55), 58.70 (43.40), 94.90 (42.10) and 100.30 (47.50); NN50 - 137.50 (100.25), 116.00 (90.50), 137.00 (81.00) and 156.00 (81.50). The frequency domain indices - LF power 1015.00 (1098.75), 945.00 (831.00), 1465 (642.25), and 1211.00 (811.37); HF power - 1324.00 (1707.00), 988.00 (1426.50), 2409.00 (1387.50), and 2219.00 (1752.00); Total power - 3374.50 (3094.25), 2757.00 (2641.00), 5202.00 (2501.50) and 5273.00 (3507.50); LFnu - 45.44 (16.61), 47.63 (29.98), 38.59 (11.81) and 37.10 (11.21); HFnu - 54.56 (16.61), 52.37 (29.98), 61.41 (11.81) and 62.90 (11.21). CONCLUSION: We have given sex and physical activity stratified HRV normative data for adolescents in the age between 12-17 years.