Mohammed Abdul Hannan Hazari

Serum calcium level in hypertension.

Background: The alterations in extracellular calcium level may influence intracellular calcium level and possibly play a role in the pathogenesis of essential hypertension. Aim: The purpose was to find out the association between serum calcium levels and hypertension; and to compare the serum calcium levels between normotensive controls, hypertensive subjects on calcium channel blockers, and hypertensive subjects on antihypertensive medication other than calcium channel blockers. Materials and Methods: Thirty one individuals including normotensives (n = 12) and hypertensives (n = 19) were enrolled for the study and their blood pressure recorded. Hypertensive group was sub divided into two: hypertensives on calcium channel blockers and hypertensives on antihypertensive medication other than calcium channel blockers. Serum calcium levels were measured by Accucare Calcium Arsenazo III kit. Differences between the groups were analyzed using ANOVA. Results: No significant difference in serum calcium level was found between normotensive and hypertensive groups; and no correlation was found between calcium levels and the blood pressure. Also the difference in serum calcium levels in hypertensive group on calcium channel blockers and those on antihypertensive other than calcium channel blockers was insignificant. Conclusions: Serum calcium levels are tightly regulated. Subtle changes in serum levels do not affect blood pressure.

Effect of ongoing isometric handgrip exercise on the inspiratory and expiratory reserve volumes

Background: Chronic diseases such as hypertension and diabetes have shown improvement in disease condition on isotonic exercises. But the same can cause deterioration in the health of patients with asthma, heart failure, and chronic obstructive pulmonary disease. Therefore, in such individuals, isometric exercise can be given a try. Isometric exercise is known to activate the autonomic nervous system, especially the parasympathetic fibers and thus has a bearing on the functioning of respiratory system. Aims and Objectives: This study was undertaken with a purpose to find acute change in respiratory reserve during handgrip exercise. Materials and Methods: 50 young apparently healthy volunteers between the ages of 18 to 35 years were enrolled for the study. Different spirometry volumes and capacities including inspiratory reserve volume (IRV) and expiratory reserve volume (ERV) were recorded on MedSpiror (RMS, Chandigarh, India) at baseline and during sustained hand grip using a hand dynamometer. Statistical analysis was done using SPSS 17.0 on the data obtained. Result: This study showed that FVC was significantly reduced during handgrip exercise. FEV1, PEFR, FEF 25–75% and IRV decreased while FEV1/FVC and ERV increased but these changes were not significant statistically. Conclusion: The reserve capacity of the lung does not change significantly during isometric exercise.

Observational study on the prevalence of diabetes mellitus among ultrasonographically diagnosed cholelithiasis patients

Background and Aim: Diabetes and cholelithiasis are common diseases worldwide in this era of modern epidemics of non - communicable diseases. Studies revealed that diabetes is a risk factor for gallstones. Since both diseases are related to altered carbohydrate and lipid metabolism, we hypothesized that the vice-versa, i.e., gallstone disease can be a risk factor for the development of diabetes. The aim of this study was to find the prevalence of diabetes mellitus among ultrasonographically diagnosed cholelithiasis patients and to find any correlation between parameters of gallstones and diabetes mellitus. Methods: This was a hospital-based observational study. A total of 31 gallstone patients belonging to both genders (male = 9, female = 22) and in the age group of 20-80 years were enrolled in the study. From ultrasound report, parameters noted were: size of gallbladder, solitary or multiple gallstones, and size of the largest gallstone. All patients were asked about history of diabetes mellitus, (if history of diabetes is present - whether the diabetes was diagnosed before or after cholelithiasis), monthly family income, education status, and occupation. Data obtained were subjected to appropriate statistical analysis. P < 0.05 was considered statistically significant. Results: In this endeavor, we found that the prevalence of diabetes among cholelithiasis patients was only 35.48%; and of the 11 diabetic patients, 3 developed gallstones before the diagnosis of diabetes mellitus. Socioeconomic status did not have any bearing on the occurrence of diabetes and gallstones in our patients. Glycated hemoglobin levels did not correlate with the severity of gallstone disease which is assessed in the form of solitary/multiple stones and size of the largest gallstone. Conclusion: There is no increased prevalence of diabetes among cholelithiasis patients. Our hypothesis of gallstones acting as risk for developing diabetes could not be proved.

Evolution of automaticity of heart pacemaker studied from a theoretical perspective

The pacemaker of the mammalian heart had developed a robust and yet a flexible system in the course of evolution whose function is based on multiple interactions at the sub-cellular, cellular and finally at the tissue level. These, in turn, should respond to extrinsic signals. Cardiac action potentials were explained for a long time based on the changes that occur at the cell surface. New hypothesis was put forward at the turn of the century that pointed to the role of intracellular calcium clock. Discovery of ryanodine receptors, fluorescence labeling techniques, confocal imaging and finally computer modeling of physiological processes had brought about a noticeable change that allowed development of a new concept of pacemaker automaticity. Reviewing all these developments we hereby put forward a few theoretical formulations that can turn out to be new instruments in advancing our knowledge of cardiac physiology. We had theorized that cardiac muscle is an emergent property of smooth muscle in the course of evolution, and that pacemaker activity of the cardiac muscle underwent a phase transition that finally led to the evolution of a structural pacemaker.

Baroreceptor and Chemoreceptor Reflex Contribution in Cardiovascular Changes during Exercise

During exercise, both baroreceptors and chemoreceptors contribute in bringing about the cardiovascular changes, but less is documented about the contribution made by either of these mechanisms. The purpose of the present study was to demonstrate the differential effects of baroreceptors and chemoreceptors on cardiovascular parameters during exercise. Twelve healthy individuals were subjected to exercise maneuver on stationary cycling machine. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and electrocardiogram (ECG) were recorded during rest and immediately after exercise. Heart rate (HR) and heart rate variability (HRV) was computed from ECG. SBP, DBP, mean arterial blood pressure (MABP) and HR significantly increased due to exercise. Increase in SBP, DBP, Pulse pressure (PP), MABP and HR were more pronounced when chemoreceptor influence was not considered as against when changes due to both baroreceptors and chemoreceptors were considered. The HRV analysis reflected increase in the low-frequency (LF) power % and decrease in high-frequency (HF) power % along with reduction in LF/HF ratio due to exercise, but these changes were statistically not significant. Baroreceptors through baroreflex mechanism overall increase the CVS parameters. The novel finding in this study was the opposing action of chemoreceptor mechanism to that of baroreceptor mechanism in cardiovascular homeostasis during exercise.