Impact of Vitamin D3 Administration on Cardiac Autonomic Tone in Asthma Chronic Obstructive Pulmonary Disease(COPD) Overlap Patients

Previous studies reported earlier age of onset, symptom with longer duration, more exacerbation and devoid of adequate health care in Asthma Chronic Obstructive Pulmonary Disease (COPD) Overlap (ACO) patients compared to asthma and Chronic Obstructive Pulmonary Disease (COPD) alone. However their prevalence rate was reported between 15 and 55%. Existence of asthma and COPD has been reported in between 15-20% of patient. There is no population based data on ACO patients in Bangladesh. But one study very recently reported 11.6% of Asthma COPD Overlap (ACO) patients in this country. Thus it is of utmost importance to perform more research on this significant disease. Several studies investigated autonomic function in asthma and COPD patients. Both asthma and COPD affect cardiac autonomic function. Poor asthma control is associated with lower HRV, depressed sympathetic and enhanced parasympathetic modulation. It has reported that the risk of cardiovascular disease in COPD is increase by 2 to 3 fold and it is the leading cause of death in mild to moderate COPD. But to the best of our knowledge no study investigated the cardiac autonomic function of ACO patients. Vitamin D deficiency is a common feature in ACO patient. Previous studies demonstrated the relationship between vitamin D deficiency and reduced HRV resulting in incidence of cardiovascular disease. Only one study reported the effect of vitamin D administration on HRV. They enrolled young healthy subjects and observed the effect of vitamin D on HRV in response to physiological stressor such as angiotensin II induced stress. All these subjects were vitamin D insufficient and their result showed improvement of sympathovagal balance after administration of vitamin D. With this experimental observation we can expect, administration of vitamin D in vitamin deficient ACO patients might improve cardiac autonomic function and thereby protect them from the risk cardiovascular morbidity and mortality. However vitamin D appears to be a simple, cost effective treatment to reduce cardiovascular disease associated risk by improving function of autonomic nerve function in both healthy and chronic disease population worldwide. But the volume of information regarding the effect of vitamin D administration in ACO patients is not enough for reaching any final conclusion. Moreover, with the best of our knowledge no study have been conducted to observe the effects of this fat soluble vitamin on HRV in vitamin D deficient, stable patients with ACO. Therefore, on the basis of this background the present study has been designed to evaluate the effects of Vitamin D on heart rate variability in D deficient, stable patients with ACO. This study will draw attention of the physicians on the cardiac autonomic status of ACO patients and the effects of Vitamin D on it. General Objectives: This study will assess the impact of vitamin D therapy on cardiac autonomic tone in vitamin D deficient ACO patients by heart rate variability analysis. Specific Objectives: * To measure HRV by time domain and frequency domain and nonlinear methods in vitamin D deficient ACO patient at baseline. * To measure all these above parameters after 3 months of vitamin D and placebo administration. * To Compare pre and post intervention HRV parameters in both vitamin D group and placebo group of ACO patients. Methods 1. Study design: This study will be a randomized controlled trial where experiment will be done with either vitamin D therapy or with placebo for 3 months onward. 2. Study center: This study will be carried out in the department of Physiology of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka under continuous supervision and monitoring. 3. Period of study: This study will commence from September, 2017 and expected to end by August, 2018. 4. Ethical Clearance: The protocol of this study involving the human subjects will be submitted to Institutional Review Board (IRB) of Bangabandhu Sheikh Mujib Medical University (BSMMU) for ethical and other technical approval before commencing the actual study.this project is a part of an ongoing research which was approved by Institutional Review Board (IRB) of Bangabandhu Sheikh Mujib Medical University (BSMMU). 5. Sampling: Sample size: Total 60 subjects will be recruited in this study, which is designed for randomized controlled trial on the basis of outcome measures (effect size) i.e. estimation of mean differences between pre \& post intervention mean of the study which has already been published in a cross sectional study that assess the association of vitamin D deficiency with cardiac autonomic activity. Sample size based on effect size . Sampling Technique: Simple random sampling will be adopted to select the patients. According to the selection criteria total 60 subjects of both male and female with specific age range suitable for the aim and objective of the study will be enrolled. These diagnosed ACO patients (diagnosed by applying the "tick box" approach recommended by the joint committee of GOLD \& GINA from Out Patient Department (OPD) of NIDCH) will be selected by clinicians in OPD of National Institute of the Disease of Chest and Hospital (NIDCH). Grouping of the subjects: After a careful brief interview, selection and enrollment of the subjects for this study will be done. All the subjects will be divided into following groups according to the objectives of the study Baseline group: This group will include 60 vitamin D deficient ACO patients. Group A: 25 diagnosed vitamin D deficient ACO patients will be included in this group and they will be given vitamin D. This group will be further divided into the following group. Group A0: Vitamin D deficient ACO patients with placebo at day 0. Group A90: Vitamin D deficient ACO patients with placebo at day 90 Group B: 25 diagnosed vitamin D deficient ACO patients will be included in this group and they will be given placebo. This group will be further divided into the following group. Group B0: Vitamin D deficient ACO patients with vitamin D at day 0. Group B90: Vitamin D deficient ACO patients with vitamin D at day 90. All the patients will be similar by age, sex and BMI. 8\. Study intervention: The intervention will be given by oral administration of vitamin D3 capsule each of which contain 40000 International Unit (IU) of vitamin D. The capsule will be manufactured and supplied by Beximco Pharmaceutical Limited, Bangladesh. The placebo will also be manufactured and supplied by the same pharmaceutical company and will be similar in size shape \& appearance to vitamin D capsule but it will contain sucrose powder. All patients will be advised to take 2 capsule after breakfast on a fixed day of the week for 3 consecutive months. At the time of enrollment all patients will be randomized to one of the two interventions (placebo or vitamin D) immediately. The intervention will be double blind randomized and cross over design so that each patient will act as his/her control. Each participant of the placebo group \& vitamin D3 group will be studied before \& after intervention and comparison will be done between these two groups. In addition comparison will be done post intervention data of placebo \& vitamin D group. 9\. Study procedure: On the first day of enrollment the researcher will introduce herself to the patient and ask for permission to talk to them. Then she will cordially explain about the objectives, purpose, and procedure of the study on the day of enrollment. The benefit as well as risk (if any) of the study should be carefully mentioned. Special emphasis will be given on explaining how he/she will be benefited from this study. The patient will be motivated for voluntary participation and will be allowed to withdraw him or herself from the study even after participation, whenever the patient feels uneasy. If he or she agrees to be a part of the study, an informed written consent will be taken in a prescribed form. Detailed family history, medical history and thorough physical examination of each patient will be done and all the information will be recorded in a standard data sheet. Then all the patients will be requested to attend the Department of Physiology at 8:30 am on the day of biochemical examination On the examination day, 5 ml of venous blood will be collected and taken to the biochemistry laboratory as soon as possible for the estimation of serum 25(OH)D. BMI will also be calculated by recording height weight. After getting the biochemical report, the final selection will be done, according to the inclusion and exclusion criteria.. Randomization and blinding: As it is not possible to exclude ACO patient with hypertension and/or diabetes , we will apply stratified randomization technique according to these two confounding factors. Four strata will be formed, as hypertension, diabetes, diabetes with hypertension and without hypertension and diabetes. Whenever a patient will be selected for enrollment, he will be given an Identification Number (ID) and assigned to one of the four strata according to his characteristics. The randomization and blinding design was developed by a faculty of the Department of Physiology who is not included in the study team. The ID number and stratification will informed to the faculty. She (the faculty) will then then randomly allocate the patient in either group A (placebo) or group B (vitamin D) considering his strata so that both the group had equal number of patients from each strata. The faculty will then note down the patient ID in the allotted group and supplied principal investigator (PI) the drug (placebo or vitamin D) according to the allotted group. At the end of the study, the faculty will provide the list of the patient's ID with allotted group to the PI Data collection: All the selected patients will be then requested to come to the Department again on the next day for the HRV test with proper preparation. Preparation for HRV test: Preparation for the test will be explained to them. For HRV examination, the subject will have to take their meal by 9:00 pm and need to have a sound sleep in the previous night. From previous night up to the time of examination, they will be requested not to undergo any physical or mental stress and also avoid taking any sedatives or any other drugs that affect central nervous system (Task force, 1996).The patients will be requested to take light breakfast in the morning without tea or coffee. After that, the selected subjects will be kept in complete bed rest in supine position for 10-15 minutes in the cool and calm laboratory environment to adjust with the lab conditions. During this period, the subject will be advised not to talk, eat or drink and also not to perform physical or mental activity even sleep . Laboratory conditions and recording of HRV: The recording of HRV measures will be done by 8 active channels, power lab 8/35 (AD instrument, Australia), in the Autonomic Nerve Function Laboratory of Department of Physiology, BSMMU. The temperature of the laboratory will be maintained at 25°C-28°C and lights will be kept dim. It will also be maintained noise free. Door of the lab will be closed and no one will be allowed to enter the room during the test except the investigator and the subject. Once the HRV recording will be completed, the patients will be provided the drug (containing placebo or vitamin D3 ) and will be asked to take 2 capsule per week for consecutive 90 days. The schedule of the therapy will be explained meticulously in detail to the patients. He/she will also be informed about the possible side effect of the drug (e.g. diarrhea). If the subject is able to understand everything explained to him, then he/she will be advised to continue the drug therapy for the consecutive 90 days. If the subject finds it difficult to understand the intervention or if any side effect of the drug appears, he/she will be asked to come to the department or to contact via telephone. During this period, the subjects will be regularly monitored and encouraged to be the part of this study by maintaining regular communication through telephonic calls several times a week. A good rapport will be built up to take time to time follow-up over telephone and visiting patient's place. In addition, scheduled appointment, hot-line and follow up will be maintained properly. If the subject finds it difficult to understand the intervention or if any side effect of the drug appears, he/she will be asked to come to the department or to contact via telephone. All the selected ACO patients will be allowed to continue standard therapeutic treatment as prescribed by the physician for these three months. Along with this, all the subjects of both the groups will be advised to continue a diet according to their own choice. Subsequently, all subjects will be requested to attend the Department of Physiology, BSMMU again on the 90th day for assessment of all the above-mentioned study variables. Any subject who fails to follow the study procedure exactly during the study period will be dropped and a new one will be included to fulfill the desired total sample size. At the end of the study i.e. after 90 day vitamin D3 will be given to all the patients of placebo group.