Heritability and genetic correlations of heart rate variability at rest and during stress in the Oman Family Study.

INTRODUCTION: Individual differences in heart rate variability (HRV) can be partly attributed to genetic factors that may be more pronounced during stress. Using data from the Oman Family Study (OFS), we aimed to estimate and quantify the relative contribution of genes and environment to the variance of HRV at rest and during stress; calculate the overlap in genetic and environmental influences on HRV at rest and under stress using bivariate analyses of HRV parameters and heart rate (HR). METHODS: Time and frequency domain HRV variables and average HR were measured from beat-to-beat HR obtained from electrocardiogram recordings at rest and during two stress tests [mental: Word Conflict Test (WCT) and physical: Cold Pressor Test (CPT)] in the OFS - a multigenerational pedigree consisting of five large Arab families with a total of 1326 participants. SOLAR software was used to perform quantitative genetic modelling. RESULTS: Heritability estimates for HRV and HR ranged from 0.11 to 0.31 for rest, 0.09-0.43 for WCT, and 0.07-0.36 for CPT. A large part of the genetic influences during rest and stress conditions were shared with genetic correlations ranging between 0.52 and 0.86 for rest-WCT and 0.60-0.92 for rest-CPT. Nonetheless, genetic rest-stress correlations for most traits were significantly smaller than 1 indicating some stress-specific genetic effects. CONCLUSION: Genetic factors significantly influence HRV and HR at rest and under stress. Most of the genetic factors that influence HRV at rest also influence HRV during stress tests, although some unique genetic variance emerges during these challenging conditions.

The impact of recent screening recommendations on prostate cancer screening in a large health care system.

PURPOSE: The United States Preventive Services Task Force recently recommended against routine prostate cancer screening, stating that the risks of screening outweigh the benefits. We determined the impact of this recommendation on prostate cancer screening in a large health system. MATERIALS AND METHODS: We obtained data on all screening prostate specific antigen tests performed at University Hospitals Case Medical Center and affiliated hospitals in northeastern Ohio from January 2008 to December 2012. We examined the total number of prostate specific antigen tests ordered with time and adjusted for patient volume by fitting a regression line. The overall trend was examined and stratified by location (urban, suburban or rural), patient age and provider type (primary care or urology). RESULTS: A total of 43,498 screening prostate specific antigen tests were performed from January 2008 to December 2012. Most tests were ordered by specialists in internal medicine (64.9%), followed by family medicine (23.7%), urology (6.1%) and hematology/oncology (1.3%). Prostate specific antigen screening increased with time until March 2009, when initial screening trials were published. Prostate specific antigen testing then decreased significantly and continued to decrease after the task force recommendations. Similar patterns were noted in almost all subgroups. The greatest decrease in screening was observed by urologists and in patients in the intermediate age group (50 to 59 years). CONCLUSIONS: United States Preventive Services Task Force recommendations appeared to have decreased prostate cancer screening. The greatest impact was seen for urologists and patients in the intermediate age group. Further study is needed to determine the long-term effects of these recommendations on the screening, diagnosis, treatment and prognosis of this prevalent malignancy.

Avascular necrosis of the femoral head in children with acute lymphoblastic leukemia: a 4- to 9-year follow-up study.

Avascular necrosis of the femoral head is usually seen in children aged 1.5 to 10 years, reaching a peak incidence between the ages of 4 and 9. Avascular necrosis of the femoral head is a known complication of corticosteroid therapy in acute lymphoblastic leukemia. There are few reports in the literature regarding the natural history of this condition, and there is no consensus on its management. This study examined the natural history of avascular necrosis of the femoral head in children with leukemia. From 1993 to 2006, a total of 865 children with acute lymphoblastic leukemia were admitted to the hematology-oncology ward of a children's hospital. The diagnosis of acute lymphoblastic leukemia was established by bone marrow aspiration. Based on clinical and radiographic findings, avascular necrosis of the femoral head was found in 7 patients; these patients underwent follow-up for 4 to 9 years. Avascular necrosis of the femoral head was clinically symptomatic in all of the children, and they had advanced radiographic collapse of the femoral head. However, the head of the femur was not at risk in any patient based on clinical and radiographic findings. Patients received supportive treatment such as abduction brace and physiotherapy. After 4 to 9 years of follow-up, clinical and radiographic results were satisfactory. Provided that the head of the femur is not at risk, avascular necrosis of the femoral head in children with acute lymphoblastic leukemia may be successfully managed with nonoperative care.

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.

Effects of Transcendental Meditation on mental health: a before-after study.

BACKGROUND: Transcendental Meditation is a mental practice to put the body and mind into a state of relaxation and rest. The method was shown to reduce anxiety and stress in previous reports. This study investigates its potential benefits in enhancing mental health of an adult Muslim population. METHODS: A before-after clinical trial was conducted to evaluate the effect of a 12-week meditation course on mental health of participants who were enrolled into the study by random sampling. 28-item General Health Questionnaire (GHQ) was administered on two occasions in conjunction with a background data sheet. RESULTS: Mean age of participants was 32.4; they were 70% female and 55% married. GHQ scores improved significantly after the meditation course (p value: < 0.001). The difference was also significant in all subgroups of the population studied. In subclass analysis of the GHQ results, the before-after score improvement was significant only in the areas of somatisation (p value: < 0.001) and anxiety (p value: < 0.001). CONCLUSION: Transcendental Meditation may improve mental health of young adult population especially in the areas of somatisation and anxiety, and this effect seems to be independent of age, sex and marital status.

Are biochemical values predictive of adenoma's weight in primary hyperparathyroidism?

BACKGROUND: Preoperative laboratory findings may carry some predictive value about the size of the abnormal parathyroid tissue that needs to be removed in primary hyperparathyroidism. METHODS: In a retrospective study from 1988 to 2003, records of 71 patients with parathyroid adenoma were reviewed. The correlation between preoperative serum calcium, phosphate and parathyroid hormone (PTH) with adenoma's weight was analysed separately. RESULTS: There was a significant correlation between preoperative serum PTH and calcium with adenoma's weight (P < 0.001 and P = 0.03, respectively). The correlation between preoperative serum phosphate and adenoma's weight was not significant (P = 0.1). CONCLUSION: Preoperative PTH level cannot be used as a definite guide to the parathyroid adenoma's weight. Large parathyroid adenomas seem to secrete less PTH per unit weight than small adenomas. Calcium and phosphate do not seem to be of much value in predicting adenoma's weight in primary hyperparathyroidism.