Deepali Jaju

Non-dipping blood pressure in the metabolic syndrome among Arabs of the Oman family study.

Objective: The objective was to examine the circadian changes in blood pressure and their relation to the metabolic syndrome and its components in Omani Arabs.

Effects of overweight and leisure-time activities on aerobic fitness in urban and rural adolescents.

BACKGROUND The aim of this research was to study the effects of overweight and leisure-time activities on maximal aerobic capacity (VO(2)max) in urban and rural Omani adolescents. METHODS A total of 529 (245 males, 284 females) adolescents, aged 15-16 years were randomly selected from segregated urban and rural schools. Maximal aerobic capacity was estimated using the multistage 20-meter shuttle-run test. RESULTS The body mass index (BMI) of urban boys and girls was significantly higher than that of rural boys and girls. Urban boys and girls spent significantly less weekly hours on sports activities and significantly more weekly hours on TV/computer games than their rural counterpart. Urban boys and girls achieved significantly less VO(2)max than rural boys and girls (44.2 and 33.0 vs. 48.3 and 38.6 mL/kg/min, respectively). Maximal aerobic capacity was negatively correlated with BMI in urban boys. CONCLUSION Overweight and inactivity had significant negative effects on cardiorespiratory fitness in urban boys and girls as compared to their rural counterparts. Weight gain in adolescence requires early intervention.

Association of gene variants with susceptibility to type 2 diabetes among Omanis

AIM To investigate the association of 10 known common gene variants with susceptibility to type 2 diabetes mellitus (T2D) among Omanis. METHODS Using case-control design, a total of 992 diabetic patients and 294 normoglycemic Omani Arabs were genotyped, by an allelic discrimination assay-by-design TaqMan method on fast real time polymerase chain reaction system, for the following gene variants: KCNJ11 (rs5219), TCF7L2 (rs7903146), CDKAL1 (rs10946398), CDKN2A/B (rs10811661), FTO (rs9939609 and rs8050136), IGF2BP2 (rs4402960), SLC30A8 (rs13266634) CAPN10 (rs3792267) and HHEX (rs1111875). T2D patients were recruited from the Diabetes Clinic (n = 243) and inpatients (n = 749) at Sultan Qaboos Univesity Hospital (SQUH), Muscat, Oman. Adult control participants (n = 294) were volunteers from the community and from those visiting Family Medicine Clinic at SQU, for regular medical checkup. The difficulty in recruiting Omani participants with no family history of diabetes was the main reason behind the small number of control participants in this study. Almost all volunteers questioned had a relative with diabetes mellitus. Inspite of the small number of normoglycemic controls in this study, this sample was sufficient for detection of genes and loci for common alleles influencing T2D with an odds ratio of ≥ 1.3 reaching at least 80% power. Data was collected from June 2010 to February 2012. RESULTS Using binary logistic regression analysis, four gene variants showed significant association with T2D risk: KCNJ11 (rs5219, P = 5.8 × 10(-6), OR = 1.74), TCF7L2 (rs7903146, P = 0.001, OR = 1.46), CDKAL1 (rs10946398, P = 0.002, OR = 1.44) and CDKN2A/B (rs10811661, P = 0.020, OR = 1.40). The fixation index analysis of these four gene variants indicated significant genetic differentiation between diabetics and controls {[KCNJ11 (rs5219), P < 0.001], [TCF7L2 (rs7903146), P < 0.001], [CDKAL1 (rs10946398), P < 0.05], [CDKN2A/B (rs10811661), P < 0.05]}. The highest genotype variation % between diabetics and controls was found at KCNJ11 (2.07%) and TCF7L2 (1.62%). This study was not able to detect an association of T2D risk with gene variants of IGF2BP2 (rs4402960), SLC30A8 (rs13266634), CAPN10 (rs3792267) and HHEX (rs1111875). Moreover, no association was found between FTO gene variants (rs9939609 and rs8050136) and T2D risk. However, T2D risk was found to be significantly associated with obesity (P = 0.002, OR = 2.22); and with the Waist-to-Hip ratio (n = 532, P = 1.9 ×10(-7), OR = 2.4), [among males (n = 234, P = 1.2 × 10(-4), OR = 2.0) and females (n = 298, P = 0.001, OR = 6.3)]. CONCLUSION Results confirmed the association of KCNJ11 (rs5219), TCF7L2 (rs7903146), CDKAL1 (rs10946398) and CDKN2A/B (rs10811661) gene variants with susceptibility to T2D among Omani Arabs.

Prevalence and heritability of clusters for diagnostic components of metabolic syndrome: the Oman family study.

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 = P(dependent)/P(independent). Heritabilities were adjusted by sex and age. RESULTS The highest LDep were central obesity (CO) + high glucose level (HGl) + triglycerides (IDF, 3.08; NCEP, 4.38; WHO, 3.17; P < 0.001). Triglycerides combined with any other component were the most common cluster. The lowest LDep for IDF were high blood pressure (HBP) + CO + low HDL-C (1.21, P < 0.025); for NCEP were HBP + HGl + low HDL-C (1.21, P < 0.07). These components were gathered almost by chance alone. In contrast, the lowest LDep for WHO were HGl + CO + low HDL-C (2.01, P < 0.001). The WHO criteria yielded the highest heritability for a MetS diagnosis (h(2) = 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 cut-off points for diagnosis for increasing the sensitivity. The WHO showed the highest values for LDep for all components because they used the highest cut-off points.

Genome-Wide Linkage Analysis of Hemodynamic Parameters Under Mental and Physical Stress in Extended Omani Arab Pedigrees: The Oman Family Study

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 ventricular ejection time (LVET), respectively. For △WCT, suggestive QTLs were detected for CO on chr11 (LOD = 2.5), LVET on chr3 (LOD = 2.0) and EDI on chr9 (LOD = 2.1). For CPT, suggestive QTLs for HR and LVET shared the same region on chr22 (LOD 2.3 and 2.8, respectively) and on chr9 (LOD = 2.3) for SBP, chr7 (LOD = 2.4) for SV and chr19 (LOD = 2.6) for CO. For △CPT, CO and TPR top signals were detected on chr15 and 10 (LOD; 2.40, 2.08) respectively. CONCLUSION Mental stress revealed the largest number of significant and suggestive loci for normal BP reported to date. The study of BP and its intermediate phenotypes under mental and physical stress may help reveal the genes involved in the pathogenesis of essential hypertension.

Heritability of hemodynamic reactivity to laboratory stressors in a homogenous Arab population: 'Oman Family Study'

BACKGROUND Exaggerated cardiovascular reactivity to stressful stimuli may be a risk factor for the development of hypertension. The genetic influence on blood pressure (BP) reactivity to stress and its control mechanisms has been receiving considerable support. This study aims at examining the heritability of BP and its intermediate hemodynamic phenotypes to acute stress in a homogeneous Arab population. METHODS Parameters were computed from continuous BP, electrocardiography and impedance cardiography measurements, during rest, word conflict (WCT) and cold pressor (CPT) tests. Heritability estimates (h(2)) were obtained using the variance components-based approach implemented in the SOLAR software package. RESULTS Reactivity scores for WCT and CPT increased significantly (P < .05) for systolic (SBP), diastolic (DBP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR). They decreased significantly (P < .05) for stroke volume (SV), left ventricular ejection time (LVET), end diastolic (EDI) and cardiac contractility (IC) indices. Univariate analysis detected heritability estimates that ranged from 0.19-0.35 for rest, 0.002-0.40 for WCT and 0.08-0.35 for CPT. CONCLUSION In this unique cohort, resting as well as challenged cardiovascular phenotypes are significantly influenced by additive genetic effects. Heritability estimates for resting phenotypes are in a relatively narrow range, while h(2) for their reactivity is somewhat broader with lower estimates. Further analyses of this study may offer important opportunities for gene finding in hypertension. WHAT IS KNOWN ABOUT THE TOPIC: (1) cardiovascular reactivity to stress predicts cardiovascular disease; (2) genetic susceptibility plays an important role in stress reactivity. Family studies using the cold pressure test reported significant heritability for blood pressure. WHAT THIS STUDY ADDS (1) this cohort is from five highly consanguineous isolated Arab pedigrees with genetically verified genealogical records and environmental homogeneity; (2) This is the first study to estimate heritability of detailed intermediate hemodynamic phenotypes that make up normal blood pressure.

Differing Definition-Based Prevalence of Metabolic Syndrome in the Women of Oman Family Study: A Function of Multiparity

OBJECTIVE The aim of this study was to investigate causes of the prevalence of the metabolic syndrome in multiparous Omani Arab women using the International Diabetes Federation definition (IDF). RESEARCH DESIGN AND METHODS Of 392 married women (mean age 40 years), 354 (90%) were multiparous with an average parity of 8. They were divided into four parity groups: Para 0, Para 1-3, Para 4-6, and Para >6. Body mass index (BMI), waist circumference, fasting, and 2-hour glucose and insulin, plasma lipids, serum leptin, and homeostasis model assessment for insulin resistance (HOMA-IR) and blood pressure (BP) were measured. RESULTS In the whole cohort, the IDF definition identified 28% women with the metabolic syndrome, whereas it identified 48% in Para >6. In comparison, the National Cholesterol Education Program (NCEP) definition identified 21% and 39%, respectively (kappa = 0.642). Waist circumference was positively associated with the number of live births (beta = 0.78, p = 0.0001). Compared to other individual IDF criteria, only age-adjusted large waist circumference carried the highest risk for having the metabolic syndrome in all groups (odds ratio [OR], 2.3, 95% confidence interval [CI], 1.0-5.4, 3.2, CI, 1.3-8 and 4.8, CI, 2.1-11.2). CONCLUSION The high prevalence of the metabolic syndrome in multiparous Omani Arab women appeared to be influenced by the parity-related large waist circumference. The high dependency of the IDF criteria on waist circumference for the definition of the metabolic syndrome in this population has led to the misclassification of such women.

Classification of sleep apnea using wavelet-based spectral analysis of heart rate variability

BACKGROUND 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. OBJECTIVE 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. METHODS 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 sleep laboratory of Sultan Qaboos University hospital in Oman. Four different classification versions have been used in this work. RESULTS Accuracy result of 90% was obtained between severe and normal subjects and 85% between mild and normal and 75% between severe and moderate and 83.75% between normal and patients. CONCLUSIONS The VLF/LF power spectral ratio of the wavelet-based soft-decision analysis of the RRI data after a high-pass filter resulted in the best accuracy of classification in all versions.

Vincristine-induced neuropathy in pediatric patients with acute lymphoblastic leukemia in Oman: Frequent autonomic and more severe cranial nerve involvement

Vincristine (VCR) induced peripheral neuropathy is a common complication in children with acute lymphoblastic leukemia (ALL).

Identification of patients with preeclampsia from normal subjects using wavelet-based spectral analysis of heart rate variability

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.