Background: Hyperthyroidism is associated with altered cardiac autonomic nervous activity (CANA). Heart Rate Variability (HRV) analysis is a promising technique to quantify CANA and therefore can be done in hyperthyroidism. Objective: To observe the HRV parameters in patients with hyperthyroidism to find out the influence of excess thyroid hormone on cardiac autonomic nervous activities. Method: The cross sectional study was carried out on 60 hyperthyroid patients (groupB)aged 30-50 years in the Department of Physiology, BSMMU, Dhaka from 1 st July 2007 to 30 th June 2008. Age and sex matched 20 apparently healthy euthyroids were also studied for comparison (group A). On the basis of treatment, they were further divided into group B 1 consisting of 30 untreated newly diagnosed patients and group B 2 consisting of 30 hyperthyroid patients treated with antithyroid drugs for at least 2 months. The patients were selected from the Out Patient Department of Endocrinology, BSMMU, Dhaka. To assess thyroid status, serum TSH and serum FT 4 levels were measured by AxSym system and time domain measures of HRV such as mean R-R interval, mean heart rate, SDNN and RMSSD were assessed from 5minute(short term) ECG recording by a polygraph. For statistical analysis Mann-Whitney U test was done. Results: Mean R-R interval was significantly (P<0.001) lower but mean heart rate was significantly (P<0.001) higher in untreated patients than those of treated and euthyroids subjects. These values were found almost similar when compared between euthyroids and treated hyperthyroids. Similarly SDNN and RMSSD were significantly lower in untreated hyperthyroids than both euthyroids (P<0.001) and treated hyperthyroids (P<0.01). Conclusion: This study concluded that decreased vagal modulation on heart rate may occur in hyperthyroidism, which may be restored following adequate treatment of the disease.

Background: Pre-eclampsia is the most common medical complication of pregnancy associated with increased maternal and infant mortality and morbidity. Reduced serum calcium and zinc levels are found associated with elevated blood pressure in preeclampsia. Objective: To observe serum calcium and zinc levels in preeclamptic women. Methods: This cross sectional study was carried out in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University, Shahbag, Dhaka between July 2009 to June 2010. In this study, 60 pregnant women of preeclampsia, aged 18-39 years with gestational period more than 20th weeks were included as the study (group B). For comparison age and gestational period matched 30 normotensive pregnant women control (group A) were also studied. All the subjects were selected from Obstetric and Gynae In and Out patient Department of BSMMU and Dhaka Medical College Hospital. Serum calcium was measured by Colorimetric method and serum zinc was measured by Spectrophotometric method. Data were analysed by independent sample t test and Pearson's correlation coefficient test. Results: Mean serum calcium and zinc levels were significantly (p<0.001) lower in study group than those of control group. Again, serum calcium and zinc showed significant negative correlation with SBP and DBP in preeclamptic women. Conclusion: This study concludes that serum calcium and zinc deficiency may be one of the risk factor of preeclampsia. Therefore, early detection and supplementation to treat this deficiency may reduce the incidence of preeclampsia.

Diabetes mellitus is a chronic metabolic disorder which affects carbohydrate, lipid and protein metabolism. There is a strong relation between some specific oligoelements and diabetes mellitus. The study was undertaken to determine serum levels of zinc and magnesium in 60 newly diagnosed uncomplicated type 2 diabetic (group I) and 60 healthy non-diabetic subjects (group II). Serum zinc and magnesium were estimated by Atomic Absorption Spectrophotometer (AAS). The serum zinc and magnesium levels were (72.70±8.43 ?g/dl) and (1.85±0.17 mg/dl) respectively in group-1 and (75.92±8.20 ?g/dl) and (2.00±0.17 mg/dl) respectively in group-11. The levels were significantly decreased in group-1. Study showed that type 2 diabetes mellitus can result in changes in zinc and magnesium levels and supplementation of both zinc and magnesium may be considered in those cases.DOI: http://dx.doi.org/10.3329/bjmb.v3i2.13811 Bangladesh J Med Biochem 2010; 3(2): 46-49

Abstract

Background: Physical inactivity and low resting heart rate variability (HRV) are associated with increased incidence of coronary heart disease. Heavy physical activity is associated with higher heart rate variability and reduces the risk of coronary heart disease Objective: To assess some time domain measures of HRV in order to compare Cardiac Autonomic Function between sedentary and heavy workers. Methods: This cross sectional study was carried out in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University between 1 st July 2008 to 30 th June 2009 on 30 apparently healthy heavy workers aged 28-50 years from low socioeconomic condition (study group). For comparison 30 age, sex, BMI and socioeconomic status matched apparently healthy sedentary subjects (group A) were also studied. The study subjects were selected among rickshaw-pullers living in the slum areas nearby BSMMU, Dhaka and the controls were from fourth class employee of BSMMU, Dhaka. Heart Rate Variability were assessed by a Polygraph. Several time domain measures of HRV such as mean R-R interval, mean HR, SDNN, RMSSD were analyzed. For statistical analysis, Independent-Samples t-test, and Pearson's correlation coefficient tests were done as applicable. Results: Resting mean heart rate (P<0.01), SDNN (P<0.01) and RMSSD (P<0.001) were significantly lower but mean R-R interval (P<0.001) was significantly higher in heavy workers than those of sedentary control. The mean R-R interval (P<0.05) showed significant positive correlation in heavy workers but significant negative correlation in sedentary workers with BMI. Conclusion: Cardiac autonomic nerve function status may be higher with parasympathetic dominance by increased physical activity.

No abstract

Background: Cardiac autonomic nervous activities (CANA) deteriorate with age, obesity, sedentary life style and in various cardiac and noncardiac disease conditions. Regular physical exercise may improve CANA in health and diseases. Power spectral analysis (PSA) of Heart rate variability (HRV) is one of the most promising newer techniques to quantify CANA. Objective: To analyze HRV by Power Spectral method in order to find out the influence of regular physical exercise on CANA in male adolescent athletes. Method: This cross sectional study was carried out on 62 adolescent male athletes aged 12-18 years (group B), in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University from 1 st July 2007 to 30 th June 2008. For comparison, 30 age, sex, BMI and socioeconomic condition matched apparently healthy sedentary subjects (group A) were also studied. The study subjects were selected from the BKSP (Bangladesh Krira Shikka Prothistan, Savar, Dhaka) and the control from a residential school of Dhaka city.Power spectral measures of HRV including Total Power (TP), Very Low Frequency Power (VLF) Low Frequency(LF), High Frequency (HF) LF/HF were measured by a Polygraph . For statistical analysis, Idependent-Sample t-test was used. Results: Total power, HFnu power and the VLF,LF,HF were significantly (P<0.001) higher and LFnu power and the LF/HF ratio were significantly (P<0.001) lower in athletes than those of nonathletes which indicate higher cardiac parasympathetic and lower sympathetic activity in athletes. Conclusion: Cardiac Autonomic regulation with increased parasympathetic and decreased sympathetic modulation may occur with in athletes engaged with regular physical exercise.

Background: Obesity is an important and independent risk factor for cardiovascular morbidity andmortality. High incidence of cardiac autonomic nerve dysfunction has been noted in obese subjectswho are at increased risk for sudden death Objective: To study the relationship between sympatheticnerve function and obesity. Methods: This cross sectional study was conducted in the Department ofPhysiology, Bangabandhu Sheikh Mujib Medical University between July 2006 to June 2007 and 40apparently healthy obese subjects aged 18-40 years of both sexes with BMI ≤ 25 kg/m2 in study group.Age and sex matched 40 apparently healthy nonobese subjects with BMI range of 18.5-22.9 kg/m2were also included for comparison (Control). Two noninvasive cardiovascular reflex tests like bloodpressure response to sustained handgrip and blood pressure response to standing were done toassess sympathetic nerve function status. Unpaired Student's 't' test and Pearson correlation coefficienttest were used for statistical analysis. Results: Mean values of resting heart rate, resting systolic anddiastolic blood pressure were significantly (p<0.05) higher and both the sympathetic nerve functionparameters (BP response to hand grip and BP response to standing) were significantly (p>0.05) lowerin obese compared to those of non obese control subjects. Again, BP response to hand grip werenegatively and BP response to standing were positively correlated with BMI in all subjects. Thesecorrelations are statistically significant (p<0.05). Conclusion: The results of this study revealed thatsympathetic nerve function may be reduced in obesity.Key words: sympathetic nerve function; obesity; BMIDOI: 10.3329/jbsp.v5i1.5416J Bangladesh Soc Physiol. 2010 June; 5(1): 34-39