Objective: To estimate the prevalence of type 2 diabetes (T2D) complications and associated condi... more Objective: To estimate the prevalence of type 2 diabetes (T2D) complications and associated conditions among Omani patients at Sultan Qaboos University Hospital (SQUH). Methods: A total of 986 T2D Omani patients was included in this study. Data were collected from June 2010 to February 2012. Data include demographic, anthropometric and biochemical investigations. Complications among patients were recorded. Results: Thirty-six percent of the patients were overweight and 51% were obese. Thirty-five percent of the patients had high serum total cholesterol, 63% had high LDL cholesterol, 38% had high serum triglycerides, while 50% and 48% of the males and females, respectively, had low HDL cholesterol. Half of the patients had at least one T2D complication, while 86% had a complication or associated condition. Twenty percent had coronary artery disease, 5% had a stroke, 66% had hypertension, 10% had documented retinopathy, 15% had microalbuminuria, 31% had nephropathy, 9% had neuropathy and 2% had peripheral vascular disease. Conclusion: The prevalence of diabetes complications and associated conditions among Omani T2D patients was not different from other populations. However, prevalence of retinopathy and neuropathy was lower and this indicates the need for a proper assessment and documentation.
Background: Hypertension and changes in autonomic functions commonly accompany the acute phase of... more Background: Hypertension and changes in autonomic functions commonly accompany the acute phase of ischemic stroke and are recognized to influence outcomes. Few studies have addressed hemodynamic and autonomic monitoring together in acute stroke. Aim: We aimed to study serial hemodynamic and cardiovascular autonomic changes among patients with acute ischemic stroke (AIS) using thoracic electrical bioimpedance and to explore their relation to stroke outcome, stroke type, location, and severity. Methods: Patients with AIS of <96 h duration underwent serial hemodynamic/autonomic function studies over the first 4 days of admission. Their association with stroke severity, type, location, and outcome was explored using univariate and multivariate analyses. Patients with arrhythmias, pulmonary edema, or cardiac failure were excluded. Results: Of the 55 patients (M:F::27:28; age: 62 + 12 yrs) with AIS, 33 had large artery stroke, 18-lacunar and 4-cardioembolic stroke, and 6 died. Mean blood pressure, systemic vascular resistance (SVR), and cardiac output (CO) decreased over 4 days. Several hemodynamic and autonomic parameters correlated with the outcome on univariate analysis, while CO and SVR independently predicted the outcome. Stroke type was related to few hemodynamic parameters (SI, cardiac index on days 2-4). Lacunar stroke type was associated with left ventricular ejection time and low-frequency/high-frequency ratio (P < .05). Conclusion: Among patients with AIS, early sympathetic autonomic dominance may explain decreasing hemodynamic trends observed over the initial 4 days. 2 hemodynamic parameters, CO and SVR, independently predicted stroke outcome, while blood pressure did not. Further studies are indicated to explore the possibility of influencing stroke outcomes through modification of CO or SVR.
Sultan Qaboos University Medical Journal, Aug 25, 2022
Objectives: This study aimed to document the distribution of PFT outcomes among adult Omani patie... more Objectives: This study aimed to document the distribution of PFT outcomes among adult Omani patients. There is limited information regarding the distribution of pulmonary diseases (PD) in Oman. Pulmonary function test (PFT) outcome patterns could indicate an indirect distribution of PD. Methods: This retrospective cross-sectional study was conducted from January to December 2015 at a tertiary hospital in Oman. A total of 1,118 adults referred for PFTs during this period were included. Results: There were 605 (54.1%) female and 513 (45.9%) male patients. The mean age of the patients was 47.11 ± 18.1 years. Most patients underwent spirometry with reversibility (36.8%) or full lung function testing with reversibility (29.7%). Among the 1,064 patients with conclusive PFT outcomes, 39.9% had normal findings, 26.1% had obstructive defects, 19.6% demonstrated restrictive defects and 10.6% had mixed obstructive/restrictive defects. Conclusion: This study generated important preliminary data regarding PFT outcomes (defects) in Omani patients.
Annals of the National Academy of Medical Sciences. India, Jul 1, 2018
Vasovagal syncope (VVS) with a sudden, temporary loss of consciousness (LoC) is a common phenomen... more Vasovagal syncope (VVS) with a sudden, temporary loss of consciousness (LoC) is a common phenomenon in the young and the elderly. Though generally described as innocuous, it may lead to serious consequences in special category of people (pilots), or in the elderly in whom LoC may lead to a fall and serious injury. The topic has been copiously researched upon and discussed in medical literature over the last few decades, but the exact mechanisms which lead to the disability have yet to be fully agreed upon. Changes in cardiovascular baroreceptor sensitivity, aberrations in the complex interaction amongst the nucleus of the tractus solitarius and the nuclei around it, inability of the peripheral circulation to respond to autonomic vasoconstrictors, or excess production of vasodilators such as nitric oxide produced locally have been considered in its pathophysiology. Various extraneous situations like dehydration, exposure to heat stress, medications, psychological factors may adversely stress regulatory physiological responses and promote occasional episodes of VVS. More complex dysautonomia could be a reason for the recurrent VVS. Differences between brain structure of VVS sufferers and normal subjects have been proposed. Head-up tilt table (HUT) test is the most widely applied investigation for evaluating VVS episodes. Lower body negative pressure (LBNP) has also been used. Enhancement of the orthostatic stress may be done by simultaneous use of both, or with peripheral vasodilators. As to whether such an enhancement is necessary is debatable. Management with increased salt and fluid intake, corticosteroids, beta adrenergic receptor blockers, alpha adrenergic receptor stimulants, selective serotonin reuptake inhibitors, and nitric oxide synthase inhibitors have been tried with variable success.
Introduction: Obstructive sleep apnea (OSA) is a common sleep disorder affecting an average of 4%... more Introduction: Obstructive sleep apnea (OSA) is a common sleep disorder affecting an average of 4% of men and 2% of women. Continuous positive airway pressure (CPAP) is the standard treatment for patients with OSA. CPAP compliance and acceptance are major problems among OSA patients and that requires a regular follow up and monitoring. This study is aimed to evaluate CPAP usage and compliance in our local population. Materials and methods: Patients recommended for CPAP treatment following overnight polysomnography (PSG) at Sultan Qaboos University Hospital during the period 2008 to 2011 were reviewed. The data were collected from patients' medical records, Polysomnography reports and by contacting them by telephone call. Comparative statistics were done between years 2008-2009 and 2010-2011. Results: Total PSGs done between years 2008-2011 were N = 779 and CPAP was recommended for 429 (55%) patients. Only 229/429 patients could be contacted. 89 patients regularly using CPAP (39%) and out of these; 50 patients had bought CPAP and 39 received CPAP through a donation service. 47 patients were using CPAP (19%) with patients who bought their own CPAP. 24 (10%) patients received donated machines. The study also showed that 49 (20%) patients refused to use CPAP, 60 (24%) patients could not purchase CPAP (for financial reasons). Comparison was performed between 2008, 2009, and 2010, 2011 it showed significant improvements (33.33%) in patients who bought their own CPAP. (30.43%) and patients who received donated machines. Conclusion: This study revealed that CPAP usage and acceptance has improved over the last two years in Omani sleep apnea patients.
Background: Exaggerated cardiovascular reactivity for blood pressure (BP) and heart rate (HR) to ... more Background: Exaggerated cardiovascular reactivity for blood pressure (BP) and heart rate (HR) to laboratory stress tests has been proposed as a predictor of cardiovascular disease. Subjects and Methods: The study was conducted in normal subject; 262 males and 280 females (mean age 30 ± 9 years, BMI 23.5 ± 4 years), from five large and highly consanguineous homogeneous Arab families of OFS. Hemodynamic parameters: Heart rate (HR), systolic, diastolic, mean BP (mmHg), Stroke index (SI, SI (ml/beat/m 2 ), cardiac index (CI,L/min/m 2 ) ), total peripheral resistance index (TPRI, yne*s*/cm 2 )), left ventricular ejection time (LVET, ms) and cardiac contractility (IC, 1000/sec ) were computed from beat-to-beat BP, ECG and impedance cardiography (TFM, CNSystems). Autonomic parameters ( LF; sympathetic , HF; parasympathetic, normalized) and baroreceptor sensitivity (BRS, ms/mmHg) were computed using spectral analysis and the sequence method, respectively. Hemodynamic and autonomic eactivity...
BACKGROUND: The spectral analysis of the heart rate variability (HRV) shows a decrease in the pow... more BACKGROUND: The spectral analysis of the heart rate variability (HRV) shows a decrease in the power of the high frequency (HF) component in preeclamptic pregnancy compared with normal pregnancy; such a decrease is associated with an increase in the low frequency (LF) and the very low frequency (VLF) power. The physiological interpretation is that preeclamptic pregnancy is associated with a facilitation of sympathetic regulation and an attenuation of parasympathetic influence of HR compared with non-pregnancy and normal pregnancy. OBJECTIVE: To use an efficient nased on spectral analysis non-invasive technique to identify preeclamptic pregnant subjects from normal pregnant in Oman. METHODS: The soft-decision wavelet-based technique is implemented to find the power of the HRV bands in high resolution manner compared to the classical fast Fourier Transform method. Data was obtained from 20 preeclamptic pregnant subjects and 20 normal pregnant controls of the same pregnancy duration, obtained from Nizwa and Sultan Qaboos University hospitals in Oman. RESULTS: The soft-decision wavelet method succeeds to identify patients from normal pregnant with specificity, sensitivity and accuracy of 90%, 80% and 85%, respectively, compared to the FFT which results in 75% specificity, sensitivity and accuracy. CONCLUSION: The LF power obtained by Soft-decision wavelet decomposition is shown to be a successful feature for identification of preeclampsia.
BACKGROUND: Myocardial revascularization by coronary artery bypass grafting (CABG) is an effectiv... more BACKGROUND: Myocardial revascularization by coronary artery bypass grafting (CABG) is an effective measure for reducing symptoms and mortality in patients with unstable or severe coronary artery disease (CAD). Autonomic function can be estimated non-invasively using heart rate variability (HRV). HRV of patients undergoing CABG is investigated before and after CABG using a soft-decision wavelet based spectral analysis. OBJECTIVE: The main purpose of this work is to evaluate non-invasively HRV in patients undergoing CABG before operation; and to monitor the status of patients through HRV investigation on day 6 and day 30 after the CABG operation. The study intends to contribute scientific value to understanding the effect of CABG on the cardiovascular autonomic function and surgical outcome. METHODS: The soft-decision wavelet-based technique is used in this work in order to measure the power spectral density of the three main bands (VLF, LF, and HF) of HRV in 24 patients undergoing CABG operation, before the operation (Group 1: G1), and 6 days after operation (Group 2: G2) and 30 days after operation (Group 3: G3). The data is obtained from Sultan Qaboos University hospital in Oman. RESULTS: The HF power increases in 22 out of 24 patients in G2 compared to G1. While the LF power decreases in 21 out of 24 patients in G2 compared to G1. Comparing G3 to G1 the LF power decreases in 20 patients. The sum of the VLF and LF power is reduced in G2 in all 24 subjects compared to G1, and in 19 subjects in G3 compared to G1. CONCLUSIONS: The power spectral density of the HF shows increase in patients recorded on day 6 after operation compared to patients before the operation. The LF shows a decrease in G2 compared to G1. The results of G3 after 30 days of operation still show an increase of the HF power and a decrease in the LF power in most of the patients compared to their values before operation.
Technology and health care : official journal of the European Society for Engineering and Medicine, 2013
Obstructive Sleep Apnea (OSA) is the cessation of breathing during sleep due to the collapse of u... more Obstructive Sleep Apnea (OSA) is the cessation of breathing during sleep due to the collapse of upper airway. Polysomnographic recording is a conventional method for detection of OSA. Although it provides reliable results, it is expensive and cumbersome. Thus, an advanced non-invasive signal processing based technique is needed. The main purpose of this work is to predict the severity of sleep apnea using an efficient wavelet-based spectral analysis method of the heart rate variability (HRV) to classify sleep apnea into three different levels (mild, moderate, and severe) according to its severity and to distinguish them from normal subjects. The standard FFT spectrum analysis method and the soft-decision wavelet-based technique are to be used in this work in order to rank patients to full polysomnography. Data of 20 normal subjects and 20 patients with mild apnea and 20 patients with moderate apnea and 20 patients of severe apnea are used in this study. The data is obtained from the...
Background: Heart rate variability (HRV) is a reliable, non-invasive, economical reflection of ma... more Background: Heart rate variability (HRV) is a reliable, non-invasive, economical reflection of many physiological and psychological factors regulating the normal heart rhythm. It is often used as an index of cardiac parasympathetic system activity. In the general population decreased HRV is an independent risk factor for morbidity and mortality. Individual differences of HRV can be attributed to genetic factors and are found to be more pronounced in subjects during stress tests. However, most published studies on the genetic influence on HRV have focused on subjects of European and African-Americans descent. In Oman Family Study (OFS) we aim to (a) estimate and quantify the contribution of genes to the variance of HRV; (b) calculate the overlap in genetic and environmental influences on HRV at rest and under stress using uni-and bivariate analyses; and (c) multipoint variance component-based linkage analysis for all HRV parameters. Methods: The OFS consists of five large, multigener...
Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a disorder characterised by repetitive upp... more Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a disorder characterised by repetitive upper airway collapse during sleep in association with daytime sleepiness. It has an estimated prevalence of 2% and 4% among middle-aged women and men respectively. The aim of the study was to look at the association of body mass index (BMI), age and gender and prevalence of OSAHS in the Omani population. Polysomnography reports and hospital medical records of all patients who took part in the Sleep Study at the Sleep Laboratory of the Clinical Physiology Department, Sultan Qaboos University Hospital, between January 1995 and December 2006, were retrospectively reviewed. Data from both sources was gathered and analysed. A total of 1,042 sleep studies were conducted with 608 valid studies for analysis. The study showed that the apnoea/hypopnoea index (AHI) >15 was more prevalent in men compared to women (47.9% versus 33.5%, P = 0.001). There was significant correlation of AHI with BMI (P ...
Background: Prevalence and heritability of metabolic syndrome (MetS) vary between populations acc... more Background: Prevalence and heritability of metabolic syndrome (MetS) vary between populations according to the currently used criteria. We examined combinations for joint probabilities and heritabilities of MetS criteria from the National Cholesterol Education Program Adult Treatment Panel III (NCEP), World Health Organization (WHO), and International Diabetes Federation (IDF) in a sample of Omani families. Methods: We included 1277 subjects from 5 pedigrees. The likelihood ratio of diagnostic cluster dependence over clustering by chance was LDep ϭ P(dependent)/P(independent). Heritabilities were adjusted by sex and age. Results: The highest LDep were central obesity (CO) ϩ high glucose level (HGl) ϩ triglycerides (IDF, 3.08; NCEP, 4.38; WHO, 3.17; P Ͻ 0.001). Triglycerides combined with any other component were the most common cluster. The lowest LDep for IDF were high blood pressure (HBP) ϩ CO ϩ low HDL-C (1.21, P Ͻ 0.025); for NCEP were HBP ϩ HGl ϩ low HDL-C (1.21, P Ͻ 0.07). These components were gathered almost by chance alone. In contrast, the lowest LDep for WHO were HGl ϩ CO ϩ low HDL-C (2.01, P Ͻ 0.001). The WHO criteria yielded the highest heritability for a MetS diagnosis (h 2 ϭ 0.9), followed by NCEP (0.48) and IDF (0.38). The rationale of the MetS diagnostics is based on insulin resistance. This base would be lost if we continue lowering cutoff points for diagnosis for increasing the sensitivity. The WHO showed the highest values for LDep for all components because they used the highest cutoff points.
Background:We performed a genome-wide scan in a homogeneous Arab population to identify genomic r... more Background:We performed a genome-wide scan in a homogeneous Arab population to identify genomic regions linked to blood pressure (BP) and its intermediate phenotypes during mental and physical stress tests.Methods:The Oman Family Study subjects (N= 1277) were recruited from five extended families of ~10 generations. Hemodynamic phenotypes were computed from beat-to-beat BP, electrocardiography and impedance cardiography. Multi-point linkage was performed for resting, mental (word conflict test, WCT) and cold pressor (CPT) stress and their reactivity scores (s), using variance components decomposition-based methods implemented in SOLAR.Results:Genome-wide scans for BP phenotypes identified quantitative trait loci (QTLs) with significant evidence of linkage on chromosomes 1 and 12 for WCT-linked cardiac output (LOD = 3.1) and systolic BP (LOD = 3.5). Evidence for suggestive linkage for WCT was found on chromosomes 3, 17 and 1 for heart rate (LOD = 2.3), DBP (LOD = 2.4) and left ventri...
Objective: To estimate the heritability of ambulatory blood pressure (BP), heart rate (HR), and b... more Objective: To estimate the heritability of ambulatory blood pressure (BP), heart rate (HR), and beat-to-beat office BP and HR in an isolated, environmentally and genetically homogeneous Omani Arab population. Methods: Ambulatory BP measurements were recorded in 1,124 subjects with a mean age of 33.8 ± 16.2 years, using the auscultatory mode of the validated Schiller ambulatory BP Monitor. Beat-to-beat BP and HR were recorded by the Task Force Monitor. Heritability was estimated using quantitative genetic analysis. This was achieved by applying the maximum-likelihood-based variance decomposition method implemented in SOLAR software. Results: We detected statistically significant heritability estimates for office beat-to-beat, 24-hour, daytime, and sleep HR of 0.31, 0.21, 0.20, and 0.07, respectively. Heritability estimates in the abovementioned conditions for systolic BP (SBP)/diastolic BP (DBP)/mean BP (MBP) were all significant and estimated at 0.19/0.19/0.19, 0.30/0.44/0.41, 0.28/...
Objective: To estimate the prevalence of type 2 diabetes (T2D) complications and associated condi... more Objective: To estimate the prevalence of type 2 diabetes (T2D) complications and associated conditions among Omani patients at Sultan Qaboos University Hospital (SQUH). Methods: A total of 986 T2D Omani patients was included in this study. Data were collected from June 2010 to February 2012. Data include demographic, anthropometric and biochemical investigations. Complications among patients were recorded. Results: Thirty-six percent of the patients were overweight and 51% were obese. Thirty-five percent of the patients had high serum total cholesterol, 63% had high LDL cholesterol, 38% had high serum triglycerides, while 50% and 48% of the males and females, respectively, had low HDL cholesterol. Half of the patients had at least one T2D complication, while 86% had a complication or associated condition. Twenty percent had coronary artery disease, 5% had a stroke, 66% had hypertension, 10% had documented retinopathy, 15% had microalbuminuria, 31% had nephropathy, 9% had neuropathy and 2% had peripheral vascular disease. Conclusion: The prevalence of diabetes complications and associated conditions among Omani T2D patients was not different from other populations. However, prevalence of retinopathy and neuropathy was lower and this indicates the need for a proper assessment and documentation.
Background: Hypertension and changes in autonomic functions commonly accompany the acute phase of... more Background: Hypertension and changes in autonomic functions commonly accompany the acute phase of ischemic stroke and are recognized to influence outcomes. Few studies have addressed hemodynamic and autonomic monitoring together in acute stroke. Aim: We aimed to study serial hemodynamic and cardiovascular autonomic changes among patients with acute ischemic stroke (AIS) using thoracic electrical bioimpedance and to explore their relation to stroke outcome, stroke type, location, and severity. Methods: Patients with AIS of <96 h duration underwent serial hemodynamic/autonomic function studies over the first 4 days of admission. Their association with stroke severity, type, location, and outcome was explored using univariate and multivariate analyses. Patients with arrhythmias, pulmonary edema, or cardiac failure were excluded. Results: Of the 55 patients (M:F::27:28; age: 62 + 12 yrs) with AIS, 33 had large artery stroke, 18-lacunar and 4-cardioembolic stroke, and 6 died. Mean blood pressure, systemic vascular resistance (SVR), and cardiac output (CO) decreased over 4 days. Several hemodynamic and autonomic parameters correlated with the outcome on univariate analysis, while CO and SVR independently predicted the outcome. Stroke type was related to few hemodynamic parameters (SI, cardiac index on days 2-4). Lacunar stroke type was associated with left ventricular ejection time and low-frequency/high-frequency ratio (P < .05). Conclusion: Among patients with AIS, early sympathetic autonomic dominance may explain decreasing hemodynamic trends observed over the initial 4 days. 2 hemodynamic parameters, CO and SVR, independently predicted stroke outcome, while blood pressure did not. Further studies are indicated to explore the possibility of influencing stroke outcomes through modification of CO or SVR.
Sultan Qaboos University Medical Journal, Aug 25, 2022
Objectives: This study aimed to document the distribution of PFT outcomes among adult Omani patie... more Objectives: This study aimed to document the distribution of PFT outcomes among adult Omani patients. There is limited information regarding the distribution of pulmonary diseases (PD) in Oman. Pulmonary function test (PFT) outcome patterns could indicate an indirect distribution of PD. Methods: This retrospective cross-sectional study was conducted from January to December 2015 at a tertiary hospital in Oman. A total of 1,118 adults referred for PFTs during this period were included. Results: There were 605 (54.1%) female and 513 (45.9%) male patients. The mean age of the patients was 47.11 ± 18.1 years. Most patients underwent spirometry with reversibility (36.8%) or full lung function testing with reversibility (29.7%). Among the 1,064 patients with conclusive PFT outcomes, 39.9% had normal findings, 26.1% had obstructive defects, 19.6% demonstrated restrictive defects and 10.6% had mixed obstructive/restrictive defects. Conclusion: This study generated important preliminary data regarding PFT outcomes (defects) in Omani patients.
Annals of the National Academy of Medical Sciences. India, Jul 1, 2018
Vasovagal syncope (VVS) with a sudden, temporary loss of consciousness (LoC) is a common phenomen... more Vasovagal syncope (VVS) with a sudden, temporary loss of consciousness (LoC) is a common phenomenon in the young and the elderly. Though generally described as innocuous, it may lead to serious consequences in special category of people (pilots), or in the elderly in whom LoC may lead to a fall and serious injury. The topic has been copiously researched upon and discussed in medical literature over the last few decades, but the exact mechanisms which lead to the disability have yet to be fully agreed upon. Changes in cardiovascular baroreceptor sensitivity, aberrations in the complex interaction amongst the nucleus of the tractus solitarius and the nuclei around it, inability of the peripheral circulation to respond to autonomic vasoconstrictors, or excess production of vasodilators such as nitric oxide produced locally have been considered in its pathophysiology. Various extraneous situations like dehydration, exposure to heat stress, medications, psychological factors may adversely stress regulatory physiological responses and promote occasional episodes of VVS. More complex dysautonomia could be a reason for the recurrent VVS. Differences between brain structure of VVS sufferers and normal subjects have been proposed. Head-up tilt table (HUT) test is the most widely applied investigation for evaluating VVS episodes. Lower body negative pressure (LBNP) has also been used. Enhancement of the orthostatic stress may be done by simultaneous use of both, or with peripheral vasodilators. As to whether such an enhancement is necessary is debatable. Management with increased salt and fluid intake, corticosteroids, beta adrenergic receptor blockers, alpha adrenergic receptor stimulants, selective serotonin reuptake inhibitors, and nitric oxide synthase inhibitors have been tried with variable success.
Introduction: Obstructive sleep apnea (OSA) is a common sleep disorder affecting an average of 4%... more Introduction: Obstructive sleep apnea (OSA) is a common sleep disorder affecting an average of 4% of men and 2% of women. Continuous positive airway pressure (CPAP) is the standard treatment for patients with OSA. CPAP compliance and acceptance are major problems among OSA patients and that requires a regular follow up and monitoring. This study is aimed to evaluate CPAP usage and compliance in our local population. Materials and methods: Patients recommended for CPAP treatment following overnight polysomnography (PSG) at Sultan Qaboos University Hospital during the period 2008 to 2011 were reviewed. The data were collected from patients' medical records, Polysomnography reports and by contacting them by telephone call. Comparative statistics were done between years 2008-2009 and 2010-2011. Results: Total PSGs done between years 2008-2011 were N = 779 and CPAP was recommended for 429 (55%) patients. Only 229/429 patients could be contacted. 89 patients regularly using CPAP (39%) and out of these; 50 patients had bought CPAP and 39 received CPAP through a donation service. 47 patients were using CPAP (19%) with patients who bought their own CPAP. 24 (10%) patients received donated machines. The study also showed that 49 (20%) patients refused to use CPAP, 60 (24%) patients could not purchase CPAP (for financial reasons). Comparison was performed between 2008, 2009, and 2010, 2011 it showed significant improvements (33.33%) in patients who bought their own CPAP. (30.43%) and patients who received donated machines. Conclusion: This study revealed that CPAP usage and acceptance has improved over the last two years in Omani sleep apnea patients.
Background: Exaggerated cardiovascular reactivity for blood pressure (BP) and heart rate (HR) to ... more Background: Exaggerated cardiovascular reactivity for blood pressure (BP) and heart rate (HR) to laboratory stress tests has been proposed as a predictor of cardiovascular disease. Subjects and Methods: The study was conducted in normal subject; 262 males and 280 females (mean age 30 ± 9 years, BMI 23.5 ± 4 years), from five large and highly consanguineous homogeneous Arab families of OFS. Hemodynamic parameters: Heart rate (HR), systolic, diastolic, mean BP (mmHg), Stroke index (SI, SI (ml/beat/m 2 ), cardiac index (CI,L/min/m 2 ) ), total peripheral resistance index (TPRI, yne*s*/cm 2 )), left ventricular ejection time (LVET, ms) and cardiac contractility (IC, 1000/sec ) were computed from beat-to-beat BP, ECG and impedance cardiography (TFM, CNSystems). Autonomic parameters ( LF; sympathetic , HF; parasympathetic, normalized) and baroreceptor sensitivity (BRS, ms/mmHg) were computed using spectral analysis and the sequence method, respectively. Hemodynamic and autonomic eactivity...
BACKGROUND: The spectral analysis of the heart rate variability (HRV) shows a decrease in the pow... more BACKGROUND: The spectral analysis of the heart rate variability (HRV) shows a decrease in the power of the high frequency (HF) component in preeclamptic pregnancy compared with normal pregnancy; such a decrease is associated with an increase in the low frequency (LF) and the very low frequency (VLF) power. The physiological interpretation is that preeclamptic pregnancy is associated with a facilitation of sympathetic regulation and an attenuation of parasympathetic influence of HR compared with non-pregnancy and normal pregnancy. OBJECTIVE: To use an efficient nased on spectral analysis non-invasive technique to identify preeclamptic pregnant subjects from normal pregnant in Oman. METHODS: The soft-decision wavelet-based technique is implemented to find the power of the HRV bands in high resolution manner compared to the classical fast Fourier Transform method. Data was obtained from 20 preeclamptic pregnant subjects and 20 normal pregnant controls of the same pregnancy duration, obtained from Nizwa and Sultan Qaboos University hospitals in Oman. RESULTS: The soft-decision wavelet method succeeds to identify patients from normal pregnant with specificity, sensitivity and accuracy of 90%, 80% and 85%, respectively, compared to the FFT which results in 75% specificity, sensitivity and accuracy. CONCLUSION: The LF power obtained by Soft-decision wavelet decomposition is shown to be a successful feature for identification of preeclampsia.
BACKGROUND: Myocardial revascularization by coronary artery bypass grafting (CABG) is an effectiv... more BACKGROUND: Myocardial revascularization by coronary artery bypass grafting (CABG) is an effective measure for reducing symptoms and mortality in patients with unstable or severe coronary artery disease (CAD). Autonomic function can be estimated non-invasively using heart rate variability (HRV). HRV of patients undergoing CABG is investigated before and after CABG using a soft-decision wavelet based spectral analysis. OBJECTIVE: The main purpose of this work is to evaluate non-invasively HRV in patients undergoing CABG before operation; and to monitor the status of patients through HRV investigation on day 6 and day 30 after the CABG operation. The study intends to contribute scientific value to understanding the effect of CABG on the cardiovascular autonomic function and surgical outcome. METHODS: The soft-decision wavelet-based technique is used in this work in order to measure the power spectral density of the three main bands (VLF, LF, and HF) of HRV in 24 patients undergoing CABG operation, before the operation (Group 1: G1), and 6 days after operation (Group 2: G2) and 30 days after operation (Group 3: G3). The data is obtained from Sultan Qaboos University hospital in Oman. RESULTS: The HF power increases in 22 out of 24 patients in G2 compared to G1. While the LF power decreases in 21 out of 24 patients in G2 compared to G1. Comparing G3 to G1 the LF power decreases in 20 patients. The sum of the VLF and LF power is reduced in G2 in all 24 subjects compared to G1, and in 19 subjects in G3 compared to G1. CONCLUSIONS: The power spectral density of the HF shows increase in patients recorded on day 6 after operation compared to patients before the operation. The LF shows a decrease in G2 compared to G1. The results of G3 after 30 days of operation still show an increase of the HF power and a decrease in the LF power in most of the patients compared to their values before operation.
Technology and health care : official journal of the European Society for Engineering and Medicine, 2013
Obstructive Sleep Apnea (OSA) is the cessation of breathing during sleep due to the collapse of u... more Obstructive Sleep Apnea (OSA) is the cessation of breathing during sleep due to the collapse of upper airway. Polysomnographic recording is a conventional method for detection of OSA. Although it provides reliable results, it is expensive and cumbersome. Thus, an advanced non-invasive signal processing based technique is needed. The main purpose of this work is to predict the severity of sleep apnea using an efficient wavelet-based spectral analysis method of the heart rate variability (HRV) to classify sleep apnea into three different levels (mild, moderate, and severe) according to its severity and to distinguish them from normal subjects. The standard FFT spectrum analysis method and the soft-decision wavelet-based technique are to be used in this work in order to rank patients to full polysomnography. Data of 20 normal subjects and 20 patients with mild apnea and 20 patients with moderate apnea and 20 patients of severe apnea are used in this study. The data is obtained from the...
Background: Heart rate variability (HRV) is a reliable, non-invasive, economical reflection of ma... more Background: Heart rate variability (HRV) is a reliable, non-invasive, economical reflection of many physiological and psychological factors regulating the normal heart rhythm. It is often used as an index of cardiac parasympathetic system activity. In the general population decreased HRV is an independent risk factor for morbidity and mortality. Individual differences of HRV can be attributed to genetic factors and are found to be more pronounced in subjects during stress tests. However, most published studies on the genetic influence on HRV have focused on subjects of European and African-Americans descent. In Oman Family Study (OFS) we aim to (a) estimate and quantify the contribution of genes to the variance of HRV; (b) calculate the overlap in genetic and environmental influences on HRV at rest and under stress using uni-and bivariate analyses; and (c) multipoint variance component-based linkage analysis for all HRV parameters. Methods: The OFS consists of five large, multigener...
Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a disorder characterised by repetitive upp... more Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a disorder characterised by repetitive upper airway collapse during sleep in association with daytime sleepiness. It has an estimated prevalence of 2% and 4% among middle-aged women and men respectively. The aim of the study was to look at the association of body mass index (BMI), age and gender and prevalence of OSAHS in the Omani population. Polysomnography reports and hospital medical records of all patients who took part in the Sleep Study at the Sleep Laboratory of the Clinical Physiology Department, Sultan Qaboos University Hospital, between January 1995 and December 2006, were retrospectively reviewed. Data from both sources was gathered and analysed. A total of 1,042 sleep studies were conducted with 608 valid studies for analysis. The study showed that the apnoea/hypopnoea index (AHI) >15 was more prevalent in men compared to women (47.9% versus 33.5%, P = 0.001). There was significant correlation of AHI with BMI (P ...
Background: Prevalence and heritability of metabolic syndrome (MetS) vary between populations acc... more Background: Prevalence and heritability of metabolic syndrome (MetS) vary between populations according to the currently used criteria. We examined combinations for joint probabilities and heritabilities of MetS criteria from the National Cholesterol Education Program Adult Treatment Panel III (NCEP), World Health Organization (WHO), and International Diabetes Federation (IDF) in a sample of Omani families. Methods: We included 1277 subjects from 5 pedigrees. The likelihood ratio of diagnostic cluster dependence over clustering by chance was LDep ϭ P(dependent)/P(independent). Heritabilities were adjusted by sex and age. Results: The highest LDep were central obesity (CO) ϩ high glucose level (HGl) ϩ triglycerides (IDF, 3.08; NCEP, 4.38; WHO, 3.17; P Ͻ 0.001). Triglycerides combined with any other component were the most common cluster. The lowest LDep for IDF were high blood pressure (HBP) ϩ CO ϩ low HDL-C (1.21, P Ͻ 0.025); for NCEP were HBP ϩ HGl ϩ low HDL-C (1.21, P Ͻ 0.07). These components were gathered almost by chance alone. In contrast, the lowest LDep for WHO were HGl ϩ CO ϩ low HDL-C (2.01, P Ͻ 0.001). The WHO criteria yielded the highest heritability for a MetS diagnosis (h 2 ϭ 0.9), followed by NCEP (0.48) and IDF (0.38). The rationale of the MetS diagnostics is based on insulin resistance. This base would be lost if we continue lowering cutoff points for diagnosis for increasing the sensitivity. The WHO showed the highest values for LDep for all components because they used the highest cutoff points.
Background:We performed a genome-wide scan in a homogeneous Arab population to identify genomic r... more Background:We performed a genome-wide scan in a homogeneous Arab population to identify genomic regions linked to blood pressure (BP) and its intermediate phenotypes during mental and physical stress tests.Methods:The Oman Family Study subjects (N= 1277) were recruited from five extended families of ~10 generations. Hemodynamic phenotypes were computed from beat-to-beat BP, electrocardiography and impedance cardiography. Multi-point linkage was performed for resting, mental (word conflict test, WCT) and cold pressor (CPT) stress and their reactivity scores (s), using variance components decomposition-based methods implemented in SOLAR.Results:Genome-wide scans for BP phenotypes identified quantitative trait loci (QTLs) with significant evidence of linkage on chromosomes 1 and 12 for WCT-linked cardiac output (LOD = 3.1) and systolic BP (LOD = 3.5). Evidence for suggestive linkage for WCT was found on chromosomes 3, 17 and 1 for heart rate (LOD = 2.3), DBP (LOD = 2.4) and left ventri...
Objective: To estimate the heritability of ambulatory blood pressure (BP), heart rate (HR), and b... more Objective: To estimate the heritability of ambulatory blood pressure (BP), heart rate (HR), and beat-to-beat office BP and HR in an isolated, environmentally and genetically homogeneous Omani Arab population. Methods: Ambulatory BP measurements were recorded in 1,124 subjects with a mean age of 33.8 ± 16.2 years, using the auscultatory mode of the validated Schiller ambulatory BP Monitor. Beat-to-beat BP and HR were recorded by the Task Force Monitor. Heritability was estimated using quantitative genetic analysis. This was achieved by applying the maximum-likelihood-based variance decomposition method implemented in SOLAR software. Results: We detected statistically significant heritability estimates for office beat-to-beat, 24-hour, daytime, and sleep HR of 0.31, 0.21, 0.20, and 0.07, respectively. Heritability estimates in the abovementioned conditions for systolic BP (SBP)/diastolic BP (DBP)/mean BP (MBP) were all significant and estimated at 0.19/0.19/0.19, 0.30/0.44/0.41, 0.28/...
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Papers by Deepali Jaju