A Comparative Study of Autonomic Cardiovascular Parameters in Obese and Non-Obese Adults

Globally, the epidemic of obesity in children and young adults is on a constant rise over the past decade. Obesity makes individual highly susceptible to a variety of chronic diseases and their complications. An altered autonomic response in the form of enhanced baseline sympathetic activity, feeble response to sympathetic stimuli and compromised parasympathetic activity is observed in obesity. We have assessed potentially perturbed autonomic responses in young overweight/obese first year medical students. Methods: This cross sectional analytical study was undertaken in the research lab of the Department of Physiology, M.K.C.G. Medical College over a period of 12 months on 300 students (both males and females) to determine sympathetic and parasympathetic responses to stress using hand-grip dynamometer and sinus arrhythmia test respectively. Independent ‘t’ test, Pearson’s correlation coefficient and multiple linear regression analysis in SPSS 20.0 was used to statistically ascertain the differences for the aforementioned parameters between obese and non-obese adults. Results: Weight, Body mass index (BMI), waist hip ratio (WHR), Pulse rate (PR), baseline systolic blood pressure (BSBP) & baseline diastolic blood pressure (BDBP) is significantly greater in obese than in non-obese. BMI shows positive correlation with BSBP & BDBP (r=0.660**; p<0.001 & 640**; p<0.001) and negative correlation with ΔDBP, and E/I Ratio. A negative correlation is appreciated amongst ΔDBP and BMI (R2 = 39.6). A similar negative correlation is again seen between E/I ratio and BMI (R2 = 37.2). Conclusion: Obesity potentially alters autonomic balance with increased sympathetic and reduced parasympathetic tone posing elevated risk of cardiovascular and cerebrovascular accidents.

Derangement In Autonomic Functions With Elevated Blood Pressure

Background: Prehypertension exhibits approximately 62% of cardiovascular disease and 49% of ischemic heart disease (IHD) global morbidity burden. Heart Rate Variability (HRV) is a fundamental noninvasive technique to assess the autonomic influence on cardiovascular system using time domain and frequency domain methods. We explored the effects of family history of hypertension, prehypertension and hypertension on autonomic functions amongst natives of Uttarakhand region. Methodology: This cross sectional analytical study was designed to explore effects of family history of hypertension, pre-hypertension and hypertension on autonomic functions on 100 subjects divided in four groups using HRV analysis. Results: Autonomic function Analysis of our results showed an increased sympathetic activity among family history of hypertension, pre-hypertension and hypertension as evident by a significant increase in Low frequency normalized unit (LFnu), an increased LF/HF ratio and a significantly reduced High frequency Normalized unit (HFnu) and E/I ratio (p<0.05). Conclusion: Thus, altered cardiac autonomic functions are one of the early manifestations of raised blood pressure and can potentially be used in predicting hypertension at an early stage.

Variations and Anomalies of Coronary Artery System in Cadaveric Human Hearts.

Background: Knowledge of the normal and variant anatomy and anomalies of coronary circulation is an increasingly vital component in the management of congenital and acquired heart disease. Anatomical variations in relation to coronary artery and its branches will help cardiac surgeons for refining imaging techniques and coronary artery bypass grafting. The current study is aimed at understanding the normal patterns of coronary arteries with reference to its predominance, branching pattern, variations and anomalies. Methods: Heart specimen for this study were obtained from Department of Anatomy, SIMS Hapur and GFIMSR Ballabhgarh. The cadaveric human hearts were dissected to observe the coronary arteries and its branches. Results: The diameter of right and left coronary orifices were measured. The distance of the orifices from the supravalvular ridge was also measured. The length and the diameter of the coronary arteries and its branches were measured and statistical significance was determined. Conclusion: The present study revealed that, ostium diameter of left coronary artery is larger than the right coronary artery. The outer diameter of the left coronary artery is larger than the right coronary artery. The mean lumen circumference of left coronary artery, anterior interventricular artery, right coronary artery and circumflex artery is more in males as compared to female. This knowledge is important for interpretation of the coronary angiography and surgical myocardial revascularization and paramount to cardiac surgeons for proper diagnosis and treatment of cardiac ailments and radiologists to refine image interpretation.

Comparative Anatomy of Spleen: Histomorphometric Study in Human, Goat, Buffalo, Rabbit and Rat.

Background: Comparative histology not only provides information regarding tissues of different mammals but also gives insight to understand human features in the background of informations on tissue of lower mammals. Methods: Splenic tissues from five mammals i.e., human, buffalo, goat, rabbit and rat were processed for histomorphometric study on capsule, trabeculae, lymphoid follicle and central arteriole. Result: Buffalo was one mammal having highest values for all the parameters while rat having lowest. Values in human splenic tissues are in between aforementioned maximum and minimum readings. Conclusion: Teaching materials are available in histology labs from lower mammals in medical colleges might give an insight for understanding human tissues if literature on comparative histology is made available.

Autonomic Function Tests in Prehypertensive Young Adult Males of Uttarakhand Region.

Pre-hypertensives are at increased risk for rise in blood pressure and cardio vascular morbidities. Autonomic dysfunction is both a cause and effect of high blood pressure. Considering its serious prognosis the current study was undertaken with an aim to assess autonomic functions in pre-hypertensive young adult males. Male volunteers of 20-40 years were divided into normotensives (n=44) and clinically healthy pre-hypertensives (n=44). They were subjected to anthropometric measurements, Heart Rate variability (HRV) analysis along with Standard Isometric Handgrip Test (HGT) and Sinus arrhythmia test. Analysis showed a significant increase in sympathetic activity among prehypertensives characterized by lower rise in DBP (mmHg) in response to HGT: [11.27±3.76 mmHg vs 23.95±6.29 mmHg, (p<0.05)]. Parasympathetic activity was significantly decreased among prehypertensives (HFnu: 30.02±14.43 vs 41.62±14.91, p<0.05); E/I ratio: 1.20±0.10 vs 1.32±0.10, p<0.05). Sympathovagal balance showed prominent sympathetic activity (2.85±1.78 vs 1.75±0.98; (p<0.01) among prehypertensives. Salt intake among prehypertensives was significantly higher than normotensives (21.2±1.2 gm/day vs 9.0±0.5 gm/day: P<0.001). Conclusion: Autonomic dysfunction is evident in prehypertensives with an enhanced sympathetic activity, decreased parasympathetic activity and an altered sympathovagal balance in prehypertensives, salt intake was found on a higher side. Thus lifestyle changes in the form of balanced diet and moderate exercise may be advised to attenuate the risk progression of prehypertension to hypertension.

Effect of Climatological Variables for all Seasons on the Frequency of Incident Stroke Hospitalizations in Scotland.

Background: Stroke is a disease, which has a complex multi-factorial etiology. Non-modifiable risk factors are genetics, familial history, age, sex, ethnicity and race, whereas smoking, drinking, physical activity and diet can be modified to reduce the risk of stroke significantly. Aims: The aim of the present study was to see the association between climate variations and incidence of stroke in Scotland. Methods: We have obtained the stroke data as SMR01 (Scottish Morbidity Record 01) as 1,57,639 incident stroke hospitalization in Scotland between 1986 and 2005. To observe for variation in weather parameter, with first stroke incidences per day, daily mean temperature, total rainfall and average daily atmospheric pressure were compared with the frequency of incident strokes per day using ANOVA (Analysis of Variance). Result: An overall meteorological analysis of incident strokes per day reveals an inverse statistically significant relationship for average daily temperature (P<0.001) whereas total daily rainfall (P=0.03) and average daily atmospheric pressure (P=0.05) exhibit borderline significance. Correlation of low temperature with stroke might be due to the concurrent occurrence of respiratory infections. We suggest some precautionary measures to minimize the chance of stroke i.e. protection from cold weather, decrease alcohol consumption and maintaining blood pressure within a safe range during winter season. Conclusion: Overall, high stroke incidence during winter season is a combined effect of temperature, rainfall, atmospheric pressure.

Comparative Assessment of Motor Nerve Conduction Velocity among Non-Diabetic, Diabetic Non-Smoker and Sub Groups of Diabetic Smoker.

Background: Neuropathy is one of the most common complications affecting individuals with diabetes mellitus. The best evidence indicates that the etiology of neuropathy is multifactorial and is a key area of current research. Hence, this study was undertaken to test the hypothesis of alteration in MNCV (motor nerve conduction velocity) of nerves before the actual manifestation of neuropathy in type II diabetic patients and also to analyze the effect of smoking on MNCV in diabetic subjects. Methods: In the present study, 120 diagnosed diabetics were taken as cases while 30 non diabetic healthy subjects were taken as controls. Case group was divided into diabetic non-smokers and diabetic smokers. Diabetic smokers were further subdivided into light, moderate and heavy smokers, according to smoking index. After detailed history and physical examination MNCV of median and ulnar nerve in upper limb and common peroneal nerve in lower limb was performed. Result: The MNCV of median and ulnar nerves in upper limb showed no significant bilateral decreased in diabetic non-smokers and subgroup of diabetic smokers when compared with control. However, there was a significant bilateral decrease in MNCV of common peroneal nerves in the lower limb of diabetic heavy smokers when compared with control. A negative, but statistically non-significant correlation was found between MNCV and smoking index. The decrease in MNCV was dependent on smoking index by 3%, 1%, 1%, 1%, 3% and 1% in median nerve (right), median nerve (left), ulnar nerve (right), ulnar nerve (left), common peroneal nerve (right) and common peroneal nerve (left) respectively. Conclusion: The present study indicates that MNCV is more resistant to hyperglycemia induced local metabolic and microvascular changes. However, the coalition of diabetes and smoking can augment their effects many folds and can lead to motor neuropathy, reiterating the fact that smoking itself is an independent risk factor for diabetic neuropathy.

Histomorphometric Study on the Effects of Methotrexate on Gonads: An Experimental Study in Albino Rat.

Background: Prolonged use of methotrexate in juvenile arthritis and multisystem involvement due to its toxicity prompted us to find out detailed histo-morphometric study after exposure to drug. The concern became alarming because of reported gonadal damage due its direct effect on fertility. Methods: Methotrexate was injected in both male and female rats (1mg/kg, intraperitoneally), weekly for 6 weeks. Thin sections of testis and ovary of both control and experimental groups were stained with H/E stains for light microscopic examination. Results: Histomorphometric observations on seminiferous tubules included, external diameter, thickness of the wall and the diameter of the lumen. Such observations for ovarian tissue included diameters of ovarian follicles and their ova. Highly significant changes in both testicular and ovarian microscopic parameters confirmed the damage of tissue in experimental groups. Conclusion: The study suggests that utmost precaution should be taken while using methotrexate in younger patients.

Densities of Foetal Clavicles during Second and Third Trimesters.

Background: Density of bone is directly affected by mineralization, which makes visualization by ultrasonography possible to follow foetal growth from early gestation to term. Clavicle being the first bone to ossify and the only bone to transmit upper limb weight to the axial skeleton, receives special attention by the scientists. Methods: Forty-nine foetal clavicles were divided into five groups. Statistically densities of the clavicles were measured and values between groups were compared. Results: Density was constant in all the groups and both in males and females. Conclusion: It was concluded that matrix formation in clavicles keeps pace with their mineralization during 2nd and 3rd trimesters.