Underlying Risk Factors (underlying + risk_factor)

Distribution by Scientific Domains


Selected Abstracts


Risk of Serious Bacterial Infection in Isolated and Unsuspected Neutropenia

ACADEMIC EMERGENCY MEDICINE, Issue 2 2010
Elliot Melendez MD
ACADEMIC EMERGENCY MEDICINE 2010; 17:1,5 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, The objective was to determine the risk of serious bacterial infection (SBI) among children without underlying risk factors for SBI who present to the emergency department (ED) for evaluation and have unsuspected and isolated neutropenia. Methods:, This was a retrospective consecutive chart review from October 1995 through September 2003. All patients aged 0,21 years presenting to the ED of an urban tertiary children's hospital, who were documented to have neutropenia (defined as an absolute neutrophil count [ANC] of <1,000 cells/,L) without known underlying risk factor for SBI were eligible for inclusion. SBI was defined as growth of a pathogen from culture of blood, urine, or cerebrospinal fluid (CSF). Results:, There were 3,179 children with an ANC of <1,000/,L during the study period. Of these, 1,888 had no underlying immunodeficiency or central venous catheter (CVC). Fifteen of 453 (3.3%; 95% confidence interval [CI] = 1.9% to 5.4%) infants less than 3 months of age had SBI: seven with bacteremia, four with meningitis, and eight with urinary tract infections. SBI was rare among children over 3 months of age (18 of 1,435; 1.3%; 95% CI = 0.7% to 2.0%): one had bacteremia, none had meningitis, and 13 had urinary tract infections. Conclusions:, Children older than 3 months of age without underlying immunodeficiency or CVC presenting to the ED and unexpectedly found to have isolated neutropenia are not at high risk of SBI. Infants less than 3 months of age have similar risk of SBI as febrile infants of same age. [source]


Genetics of Type 2 diabetes

DIABETIC MEDICINE, Issue 5 2005
I. Barroso
Abstract Type 2 diabetes (T2D) has become a health-care problem worldwide, with the rise in disease prevalence being all the more worrying as it not only affects the developed world but also developing nations with fewer resources to cope with yet another major disease burden. Furthermore, the problem is no longer restricted to the ageing population, as young adults and children are also being diagnosed with T2D. In recent years, there has been a surge in the number of genetic studies of T2D in attempts to identify some of the underlying risk factors. In this review, I highlight the main genes known to cause uncommon monogenic forms of diabetes (e.g. maturity-onset diabetes of the young,MODY,and insulin resistance syndromes), as well as describe some of the main approaches used to identify genes involved in the more common forms of T2D that result from the interaction between environmental risk factors and predisposing genotypes. Linkage and candidate gene studies have been highly successful in the identification of genes that cause the monogenic variants of diabetes and, although progress in the more common forms of T2D has been slow, a number of genes have now been reproducibly associated with T2D risk in multiple studies. These are discussed, as well as the main implications that the diabetes gene discoveries will have in diabetes treatment and prevention. [source]


Consequences of youth tobacco use: a review of prospective behavioural studies

ADDICTION, Issue 7 2006
M. Mathers
ABSTRACT Background Cigarette smoking represents a significant health problem and tobacco has been identified as causing more preventable diseases and premature deaths than any other drug. Although health consequences from smoking have been documented, there has been a surprising lack of research into behavioural consequences. Aims To review what is known of the long-term relationship between patterns of tobacco use prior to age 18 years and behavioural consequences in adulthood. Method A literature search of electronic abstraction services from 1980 to September 2005 was conducted. To be included in the review, studies had to have large, representative samples, be longitudinal studies with baseline age under 18 years and follow-up age 18 years or older and clarify effects due to attrition, leaving 16 articles that met the inclusion criteria. Two reviewers evaluated each paper. Findings Adolescent tobacco use predicts a range of early adult social and health problems. Surprisingly few studies met the inclusion criteria. The limited evidence available suggests that adolescent tobacco smoking increases the likelihood of early adult tobacco use and the initiation of alcohol use or the development of alcohol-related problems. The link between adolescent tobacco use and subsequent cannabis use was not resolved convincingly from the studies summarized. The effects of tobacco use on later illicit drug use tended to fall away when adjusting for underlying risk factors. Existing studies of the effects of tobacco use on later mental health have many limitations. Nevertheless, a finding that youth tobacco use may predict subsequent mental health problems deserves further investigation. The possible effects of tobacco use on academic/social problems and sleep problems also warrant further investigation. Conclusion This review highlights links between youth tobacco use and subsequent behavioural and mental health problems. It provides health care professionals with evidence of the possible harmful effects of youth tobacco smoking on later social, emotional, and behavioural well-being. [source]


Analysing Perceived Downside Risk: the Component Value-at-Risk Framework

EUROPEAN FINANCIAL MANAGEMENT, Issue 4 2004
Winfried G. Hallerbach
G3; G32; G1; G14 Abstract Multinational companies face increasing risks arising from external risk factors, e.g. exchange rates, interest rates and commodity prices, which they have learned to hedge using derivatives. However, despite increasing disclosure requirements, a firm's net risk profile may not be transparent to shareholders. We develop the ,Component Value-at-Risk (VaR)' framework for companies to identify the multi-dimensional downside risk profile as perceived by shareholders. This framework allows for decomposing downside risk into components that are attributable to each of the underlying risk factors. The firm can compare this perceived VaR, including its composition and dynamics, to an internal VaR based on net exposures as it is known to the company. Any differences may lead to surprises at times of earnings announcements and thus constitute a litigation threat to the firm. It may reduce this information asymmetry through targeted communication efforts. [source]


Sleep and the metabolic syndrome

EXPERIMENTAL PHYSIOLOGY, Issue 1 2007
Robert Wolk
The metabolic syndrome represents a clustering of several interrelated risk factors of metabolic origin that are thought to increase cardiovascular risk. It is still uncertain whether this clustering results from multiple underlying risk factors or whether it has a single cause. One metabolic abnormality that may underlie several clinical characteristics of the metabolic syndrome is insulin resistance. This review discusses the evidence that sleep disturbances (obstructive sleep apnoea, sleep deprivation and shift work) may independently lead to the development of both insulin resistance and individual clinical components of the metabolic syndrome. The converse may also be true, in that metabolic abnormalities associated with the metabolic syndrome and insulin resistance may potentially exacerbate sleep disorders. The notion that sleep disturbances exert detrimental metabolic effects may help explain the increasing prevalence of the metabolic syndrome and insulin resistance in the general population and may have important implications for population-based approaches to combat the increasing epidemic of metabolic and cardiovascular disease. [source]


Relevance of the genes for bone mass variation to susceptibility to osteoporotic fractures and its implications to gene search for complex human diseases

GENETIC EPIDEMIOLOGY, Issue 1 2002
Hong-Wen Deng
Abstract We investigate the relevance of the genetic determination of bone mineral density (BMD) variation to that of differential risk to osteoporotic fractures (OF). The high heritability (h2) of BMD and the significant phenotypic correlations between high BMD and low risk to OF are well known. Little is reported on h2 for OF. Extensive molecular genetic studies aimed at uncovering genes for differential risks to OF have focussed on BMD as a surrogate phenotype. However, the relevance of the genetic determination of BMD to that of OF is unknown. This relevance can be characterized by genetic correlation between BMD and OF. For 50 Caucasian pedigrees, we estimated that h2 at the hip is 0.65 (P < 0.0001) for BMD and 0.53 (P < 0.05) for OF; however, the genetic correlation between BMD and OF is nonsignificant (P > 0.45) and less than 1% of additive genetic variance is shared between them. Hence, most genes found important for BMD may not be relevant to OF at the hip. The phenotypic correlation between high BMD and low risk to OF at the hip (approximately ,0.30) is largely due to an environmental correlation (,E = ,0.73, P < 0.0001). The search for genes for OF should start with a significant h2 for OF and should include risk factors (besides BMD) that are genetically correlated with OF. All genes found important for various risk factors must be tested for their relevance to OF. Ideally, employing OF per se as a direct phenotype for gene hunting and testing can ensure the importance and direct relevance of the genes found for the risk of OF. This study may have significant implications for the common practice of gene search for complex diseases through underlying risk factors (usually quantitative traits). Genet. Epidemiol. 22:12,25, 2002. © 2002 Wiley-Liss, Inc. [source]


Fatal postoperative pulmonary embolism in mild haemophilia

HAEMOPHILIA, Issue 2 2006
J. H. BUTCHER
Summary., The use of thromboprophylaxis in patients with haemophilia receiving factor replacement is often not considered necessary, but remains an area of debate. In this report we describe a patient with mild haemophilia A, who underwent major pelvic surgery. He had several underlying risk factors associated with the development of thromboembolism, and ultimately died as a direct consequence of multiple pulmonary emboli. The need for thromboprophylaxis and the risk balance ratio should always be considered in patients with bleeding disorders if they fall into what would otherwise be high-risk category for hospital acquired venous thromboembolism. [source]


Risk of Serious Bacterial Infection in Isolated and Unsuspected Neutropenia

ACADEMIC EMERGENCY MEDICINE, Issue 2 2010
Elliot Melendez MD
ACADEMIC EMERGENCY MEDICINE 2010; 17:1,5 © 2010 by the Society for Academic Emergency Medicine Abstract Objectives:, The objective was to determine the risk of serious bacterial infection (SBI) among children without underlying risk factors for SBI who present to the emergency department (ED) for evaluation and have unsuspected and isolated neutropenia. Methods:, This was a retrospective consecutive chart review from October 1995 through September 2003. All patients aged 0,21 years presenting to the ED of an urban tertiary children's hospital, who were documented to have neutropenia (defined as an absolute neutrophil count [ANC] of <1,000 cells/,L) without known underlying risk factor for SBI were eligible for inclusion. SBI was defined as growth of a pathogen from culture of blood, urine, or cerebrospinal fluid (CSF). Results:, There were 3,179 children with an ANC of <1,000/,L during the study period. Of these, 1,888 had no underlying immunodeficiency or central venous catheter (CVC). Fifteen of 453 (3.3%; 95% confidence interval [CI] = 1.9% to 5.4%) infants less than 3 months of age had SBI: seven with bacteremia, four with meningitis, and eight with urinary tract infections. SBI was rare among children over 3 months of age (18 of 1,435; 1.3%; 95% CI = 0.7% to 2.0%): one had bacteremia, none had meningitis, and 13 had urinary tract infections. Conclusions:, Children older than 3 months of age without underlying immunodeficiency or CVC presenting to the ED and unexpectedly found to have isolated neutropenia are not at high risk of SBI. Infants less than 3 months of age have similar risk of SBI as febrile infants of same age. [source]


Portfolio Value-at-Risk with Heavy-Tailed Risk Factors

MATHEMATICAL FINANCE, Issue 3 2002
Paul Glasserman
This paper develops efficient methods for computing portfolio value-at-risk (VAR) when the underlying risk factors have a heavy-tailed distribution. In modeling heavy tails, we focus on multivariate t distributions and some extensions thereof. We develop two methods for VAR calculation that exploit a quadratic approximation to the portfolio loss, such as the delta-gamma approximation. In the first method, we derive the characteristic function of the quadratic approximation and then use numerical transform inversion to approximate the portfolio loss distribution. Because the quadratic approximation may not always yield accurate VAR estimates, we also develop a low variance Monte Carlo method. This method uses the quadratic approximation to guide the selection of an effective importance sampling distribution that samples risk factors so that large losses occur more often. Variance is further reduced by combining the importance sampling with stratified sampling. Numerical results on a variety of test portfolios indicate that large variance reductions are typically obtained. Both methods developed in this paper overcome difficulties associated with VAR calculation with heavy-tailed risk factors. The Monte Carlo method also extends to the problem of estimating the conditional excess, sometimes known as the conditional VAR. [source]


Long-term follow-up of renal function after high-dose methotrexate treatment in children

PEDIATRIC BLOOD & CANCER, Issue 4 2008
Marika H. Grönroos MD
Abstract Background High-dose methotrexate (HD-MTX) is commonly used in treatment of pediatric leukemias and lymphomas. Transient deterioration in renal function is frequently noted during HD-MTX treatment, but possible long-term changes are less well known. In this study we aimed to study long-term renal prognosis after HD-MTX treatment, and to find possible underlying risk factors for reduced renal function. Procedure Medical records of pediatric cancer patients treated with HD-MTX were reviewed retrospectively after follow-up of 1,10 years. Renal function before and after chemotherapy was investigated in a total of 28 patients. Assessment of glomerular and tubular function was prospectively evaluated in each case. Glomerular function was evaluated by either 51Cr-EDTA or 99mTc-DTPA clearance methods, and by urinary albumin excretion. Tubular function was assessed by measuring blood electrolyte levels and urinary ,1 - or ,2 -microglobulin. Results A decrease in glomerular filtration rate (GFR) was statistically significant as follow-up time increased (P,=,0.02). Age at the time of diagnosis and exposure to potentially nephrotoxic antibiotics during cancer treatment had no influence on GFR. However, albuminuria was observed more often in patients treated with amphotericin B or gentamycin (P,=,0.04). No changes in tubular function were observed. Conclusions Our results show that HD-MTX treatment significantly decreases GFR and may cause albuminuria in pediatric cancer patients several years after treatment. Long-term renal follow-up of these patients is therefore important. Pediatr Blood Cancer 2008;51:535,539. © 2008 Wiley-Liss, Inc. [source]


Role of valproate across the ages.

ACTA NEUROLOGICA SCANDINAVICA, Issue 2006
Treatment of epilepsy in the elderly
In June 2005, a team of experts participated in a workshop with the objective of reaching agreement on several important aspects of valproate in the treatment of elderly patients with epilepsy. Epilepsy in the elderly is relatively common and its incidence increases for each decade after age 60. The aetiology and manifestations of epilepsies in the elderly are complex because of comorbidity and other underlying risk factors. A consensus was reached that elderly patients who present with a seizure disorder should be referred rapidly to a specialist and that diagnosis should be improved by using a multidisciplinary team of cardiologists, neurologists and epilepsy experts (syncope, falls and seizure specialists). This is especially important to avoid mistreatment with antiepileptic drugs (AEDs). There was consensus that the elderly are generally more susceptible to the adverse effects of AEDs than younger adults. For these reasons, in older persons AEDs should be started at low dosages, and titrated slowly according to clinical response. Some of the most troublesome side effects of AEDs in the elderly include sedation and cognitive side effects, as well as osteoporosis. Drug,drug interactions should be given special consideration. There was consensus that the pharmacokinetics of all AEDs are altered in the elderly, and that the most significant change common to all AEDs is a moderate reduction in renal and metabolic clearance. Predicting pharmacokinetic changes in the individual, however, can be very difficult because multiple factors contribute to a high inter-patient variability. There was agreement on the advantages and disadvantages of the use of valproate in the elderly, and consensus that valproate is a useful option in this population. There was no consensus, however, on whether valproate should be considered among the preferred first-line treatments in the elderly. [source]


Childhood stroke in Eastern Province, KSA: pattern, risk factors, diagnosis and outcome

ACTA PAEDIATRICA, Issue 10 2009
Abdelhady Taha Emam
Abstract Background and purpose:, Stroke has been increasingly recognized in children in recent years, but diagnosis and management can be difficult because of the diversity of underlying risk factors, atypical presentation and the absence of a uniform treatment approach. The aim of this study was to examine risk factors, clinical presentation, imaging findings and outcomes of paediatric stroke in Eastern Province, Kingdom of Saudi Arabia (KSA). Subjects and methods:, We evaluated 25 patients (11 boys and 14 girls) using computerized tomography scan of the brain, magnetic resonance (MR) imaging and MR angiography. Cardiac assessment, haematological tests, immunological tests, infection and metabolic screening were also performed in the patients. After discharge, the patients were monitored regularly in the neurology clinic to detect their outcomes. Results:, A total of 76% of the patients presented with ischaemic stroke, while the remaining 24% had haemorrhagic stroke. Sickle cell disease (SCD) was the commonest risk factor for stroke (36%) followed by non determinate causes (20%). Seizure was the commonest clinical presentation (54%) followed by haemiplegia (31%) and decreased level of consciousness (30%). Recurrence occurred in SCD patients (80%) and patients with moyamoya disease (20%). Regarding the outcome, long-term deficit was the commonest (44%), while short-term deficit and death were equal (28% each). Conclusion:, Our study in Eastern Province, KSA, showed agreement with other studies regarding risk factors, clinical presentation, imaging features and outcomes of stroke in children, yet with some points of differences, which are as follows: (1) SCD is the commonest risk factor in our study population, while in Chinese study it was not, (2) The percentage of cardiac disorders as a risk factor in this study was less than that in the European and American studies, and (3) there was relative discrepancy regarding predictors of outcome. [source]