Physical exercise and cardiac autonomic activity in healthy adult men.

Physical inactivity is an important risk factor for cardiovascular mortality and morbidity. Regular exercise is known to improve health and maintain physical fitness. The heart rate response to exercise reflects autonomic control of heart and has shown to predict cardiovascular prognosis. Decreased heart rate variability (HRV) is known as a risk factor for cardiovascular mortality. The objective of this study was to study the effect of exercise on cardiac autonomic activity. Thirty two healthy adult men in the age group of 18-25 years with normal body mass index (BMI) were recruited from different physical fitness centers, who were undergoing regular exercise for past 3 months. Resting ECG was recorded for 5 minutes and analyzed for frequency analysis of HRV. HRV parameters of the subjects were compared with fifty age and BMI matched subjects who were not undergoing any exercise program. Physical activity level of all subjects was assessed by using Global Physical Activity Questionnaire. The exercising (E) subjects were found to have a lesser heart rate (73.27±8.6 vs 74.41±8.59) compared to non-exercising (NE) group, which was not significant. No significant difference was found in frequency domain parameters of HRV between exercising and non-exercising group with LF (47.12±19.17 vs 43.55±16.66), HF (41.03±17.65 vs 46.03±15.89) and LF/HF (1.61±1.16 vs 1.22±0.93) respectively. Physical activity level was significantly different between the two groups (4175±1481.53 vs 1176.4±1103.83, p<0.001). This study showed 3 months of exercise did not have any effect on cardiac autonomic activity despite the difference in physical activity.

Cardiac Autonomic Activity in Overweight and Underweight Young Adults.

Body mass has been associated with changes in the cardiac autonomic activity. The purpose of this study was to evaluate the cardiac autonomic activity by measuring heart rate variability (HRV) in underweight and overweight young adults. Frequency-domain HRV parameters (TP, LF/ HF ratio, LF and HF in absolute and normalized units, where TP – total power, LF – low frequency power and HF = high frequency power) were measured in 124 subjects (mean age 19±1 yr), grouped according to their BMI into underweight [UW, n=12], normal weight [NW, n= 71] and overweight [OW, n=41]. BP (blood pressure) and heart rate were recorded and total body fat was calculated. The groups were similar by age and significantly differed by BMI, body fat (kg), body fat %. OW found to have higher LF in normalised units compared to NW (P<0.05). The OW had higher LF, lower HF when expressed in absolute units than NW with no statistical significance. Though not statistically significant, the LF/HF ratio, the index of sympathovagal balance was higher in OW. The UW had lower TP, LF, HF than NW with no statistical significance. The results indicate HRV is decreased in overweight young adults suggesting sympathovagal imbalance. HRV is unaltered in underweight group.

Incidence of type 1 diabetes mellitus and associated complications among children and young adults: results from Karnataka Diabetes Registry 1995-2008.

The purpose of this study was to estimate incidence of type 1 diabetes mellitus (T1DM) among children and young adults aged 0-25 years and to assess growth, glycaemic control, complications, risk factors and mortality associated diabetes mellitus,based on prospective registration of patients in Karnataka Diabetes Registry during the period 1995-2008. Complications were determined in subgroups serving as cohorts by screening tests and based on physicians' report. There were 1040 patients (514 boys and 526 girls) registered during the period 1995-2008. The overall incidence/prevalence of T1 DM (per 100,000 persons) was 3.8(0.32/10(5)/year) [males 3.7(0.3110(5)/year) and females 4(0.33/10(5)/year)]. On cross-sectional analysis of different cohorts, 88% (90/102) were below 50th percentile height, 95% (114/120) were <50th percentile of weight. Thirty-nine patients (10.7%) had poor glycaemic control (A1c>9%), The prevalence of different complications were as follows: Neuropathy 5.2% (12/230), retinopathy 8.4% (14/166), nephropathy 8.6% (20/230), hypertension 2.6% (6/230). Hypercholesterolaemia and hypertriglyceridaemia were found in 20.2% (24/119) and 41.7% (48/115) cases respectively and 18.1% (19/105) had low HDL. The percentage of patient with micro-albuminuria, high sensitive C-reactive protein were 29.6% (n=233) and 44.4% (20/45) respectively. Poor glycaemic control, hypertension and duration were strong consistent predictors of all complications. Twenty patients died during the period of which 10 deaths were related to diabetes. Though the incidence of diabetes in the young is low in our population compared to the western population, the burden of diabetes is high due to large population in our country. In spite of our best efforts there are still a huge gap between the standard of care and practice. Majority of type 1 diabetics are not reaching the ideal glycaemic targets.

Regional differences in the reference blood pressure in young Indians.

This study compares the blood pressure (BP) in young population of North India and South India. Age, height and sex specific BP was estimated for 6320 North Indian subjects aged 7-18 years and compared with BP values of South Indian subjects. North Indian boys and girls had lower diastolic BP (DBP) with no difference in systolic BP (SBP) than South Indian boys and girls between 7-12 years. Between 13-18 years North Indian boys and girls had significantly higher SBP with no difference in DBP. The significant regional differences in BP distribution among young Indians suggest considering geographic location of the population in evaluating blood pressure.

Blood pressure reference tables for children and adolescents of Karnataka.

BACKGROUND: The blood pressure levels may vary in population because of genetic, ethnic and socio economic factors. Local reference values have to be established to understand the blood pressure variable. METHODS: Blood pressure data of 2278 boys and 2930 girls in the age group of 3-18 years were analysed to study the distribution pattern of systolic blood pressure and diastolic blood pressure and to develop reference values to define hypertension. Blood pressure was measured using standardised techniques in all. The first and fifth phases of Korotkoff sounds were taken as indicative of systolic blood pressure and diastolic blood pressure respectively. Height percentiles were computed for each one year age group. According to percentiles of height 50th, 90th, 95th and 99th percentiles of systolic blood pressure and diastolic blood pressure were estimated for every one year age. RESULTS: The blood pressure (both systolic and diastolic) tends to increase with age. The stepwise regression analysis revealed that the age and height but not gender, are important determinants of blood pressure. Age and height specific, 50th, 90th and 95th and 99th percentiles of systolic and diastolic blood pressure were derived and are presented in tabular form. CONCLUSION: The blood pressure of children and adolescents can be evaluated using the reference table according to body size. The table provided helps to classify blood pressure as normal or pre hypertension and to define different stages of hypertension.