Is Rural Residency a Risk Factor for Overweight and Obesity for U.S. Children?

Objective: Despite studies suggesting that there is a higher prevalence of overweight or obese children in rural areas in the U.S., there are no national studies comparing the prevalence levels of overweight or obese rural to metropolitan children. The objective of this research was to examine the hypothesis that living in a rural area is a risk factor for children being overweight or obese. Research Methods and Procedures: Using the National Survey of Children's Heath, the prevalence of overweight and/or obese rural children was compared with that of children in metropolitan settings. Multivariate analyses were performed on the data to detect if differences varied by health services use factors or demographic factors, such as household income, gender, and race. Results: Multivariate analysis revealed that overweight or obese children ≥5 years of age were more likely to live in rural rather than metropolitan areas (odds ratio = 1.252; 95% confidence interval, 1.248, 1.256). Rural overweight U.S. children ≥5 years of age of age were more likely than their metropolitan counterparts to: be white, live in households ≤200% of the federal poverty level, have no health insurance, have not received preventive health care in the past 12 months, be female, use a computer for non‐school work >3 hours a day, and watch television for >3 hours a day. In addition, they were more likely to have comorbidities. Discussion: Living in rural areas is a risk factor for children being overweight or obese.     

Is Iron Accumulation a Possible Risk Factor for Sarcopenia?

Sarcopenia has a high incidence among the elderly, with significant negative effects on the quality of life. The pathogenesis of sarcopenia is complex, and many factors are involved in its development and progression. Sarcopenia might be associated with iron accumulation given that (1) age-related iron accumulation was found in the skeletal muscle, (2) excess iron could cause skeletal muscle damage or atrophy, and (3) patients with sarcopenia showed higher levels of serum ferritin. Understanding the etiology and pathogenesis of sarcopenia would help to develop new treatment and preventive methods, thereby improving the quality of life of the elderly patients.     

Is HIV Infection a Risk Factor for Multi-Drug Resistant Tuberculosis? A Systematic Review

Background

Tuberculosis (TB) is an important cause of human suffering and death. Human immunodeficiency virus (HIV), multi-drug resistant TB (MDR-TB), and extensive drug resistant tuberculosis (XDR-TB) have emerged as threats to TB control. The association between MDR-TB and HIV infection has not yet been fully investigated. We conducted a systematic review and meta-analysis to summarize the evidence on the association between HIV infection and MDR-TB.

Methods and Results

Original studies providing Mycobacterium tuberculosis resistance data stratified by HIV status were identified using MEDLINE and ISI Web of Science. Crude MDR-TB prevalence ratios were calculated and analyzed by type of TB (primary or acquired), region and study period. Heterogeneity across studies was assessed, and pooled prevalence ratios were generated if appropriate. No clear association was found between MDR-TB and HIV infection across time and geographic locations. MDR-TB prevalence ratios in the 32 eligible studies, comparing MDR-TB prevalence by HIV status, ranged from 0.21 to 41.45. Assessment by geographical region or study period did not reveal noticeable patterns. The summary prevalence ratios for acquired and primary MDR-TB were 1.17 (95% CI 0.86, 1.6) and 2.72 (95% CI 2.03, 3.66), respectively. Studies eligible for review were few considering the size of the epidemics. Most studies were not adjusted for confounders and the heterogeneity across studies precluded the calculation of a meaningful overall summary measure.

Conclusions

We could not demonstrate an overall association between MDR-TB and HIV or acquired MDR-TB and HIV, but our results suggest that HIV infection is associated with primary MDR-TB. Future well-designed studies and surveillance in all regions of the world are needed to better clarify the relationship between HIV infection and MDR-TB.     

Is Diabetes a Risk Factor for a Severe Clinical Presentation of Dengue? - Review and Meta-analysis

Background

The mean age of acute dengue has undergone a shift towards older ages. This fact points towards the relevance of assessing the influence of age-related comorbidities, such as diabetes, on the clinical presentation of dengue episodes. Identification of factors associated with a severe presentation is of high relevance, because timely treatment is the most important intervention to avert complications and death. This review summarizes and evaluates the published evidence on the association between diabetes and the risk of a severe clinical presentation of dengue.

Methodology/Findings

A systematic literature review was conducted using the MEDLINE database to access any relevant association between dengue and diabetes. Five case-control studies (4 hospital-based, 1 population-based) compared the prevalence of diabetes (self-reported or abstracted from medical records) of persons with dengue (acute or past; controls) and patients with severe clinical manifestations. All except one study were conducted before 2009 and all studies collected information towards WHO 1997 classification system. The reported odds ratios were formally summarized by random-effects meta-analyses. A diagnosis of diabetes was associated with an increased risk for a severe clinical presentation of dengue (OR 1.75; 95% CI: 1.08–2.84, p = 0.022).

Conclusions/Significance

Large prospective studies that systematically and objectively obtain relevant signs and symptoms of dengue fever episodes as well as of hyperglycemia in the past, and at the time of dengue diagnosis, are needed to properly address the effect of diabetes on the clinical presentation of an acute dengue fever episode. The currently available epidemiological evidence is very limited and only suggestive. The increasing global prevalence of both dengue and diabetes justifies further studies. At this point, confirmation of dengue infection as early as possible in diabetes patients with fever if living in dengue endemic regions seems justified. The presence of this co-morbidity may warrant closer observation for glycemic control and adapted fluid management to diminish the risk for a severe clinical presentation of dengue.     

Obesity as an Obstetric Risk Factor: Does It Matter in a Perinatal Center?

Objectives: Obesity before and during pregnancy is associated with several obstetrics risk factors for both mother and fetus. The aim of this retrospective study was to analyze the influence of BMI before pregnancy on distinct perinatal parameters. Research Methods and Procedures: The study includes 5067 singleton pregnancies from 2001 to 2004 at the Department of Obstetrics and Gynecology, University of Leipzig. The study group was divided into BMI groups: <18.5, ≥18.5 to <25, ≥25 to <30, ≥30 to <35, ≥35 to <40, and ≥40 kg/m². Analysis of perinatal data included rate of intrauterine death, rate of cesarean section and shoulder dystocia, time of hospital stay for mother and newborn, and gestational age of delivery. Neonatal outcome variables included percentage of newborns weighing >4000 grams, rate of umbilical cord pH <7.10, and rate of 1‐, 5‐, and 10‐minute Apgar scores of <8. Results: There was no difference in the gestational age at delivery among the groups. In the group with BMI ≥30 kg/m², the cesarean section rate was significantly elevated to 25.1%, with a more dramatic increase up to 30.2% in the group with BMI ≥35 kg/m² and 43.1% in the group with BMI ≥40 kg/m², mainly because of a higher number of secondary cesarean sections. Although newborns of obese women showed worse initial neonatal adaptation, the 10‐minute Apgar values did not differ among the groups. The higher rate of operative deliveries and the trend to an increased rate of shoulder dystocia did not influence duration of the hospital stay for mothers and newborns or morbidity of both. Discussion: A high pre‐pregnancy BMI is clearly associated with a higher rate of cesarean section deliveries. However, under the compensating conditions of a tertiary perinatal center, overall morbidity of mothers and newborns seems not to be increased.     

Is RsfS a Hibernation Factor or a Ribosome Biogenesis Factor?

Biochemistry (Moscow) - Solving the structures of bacterial, archaeal, and eukaryotic ribosomes by crystallography and cryo-electron microscopy has given an impetus for studying intracellular...     

Is Intracranial Atherosclerosis an Independent Risk Factor for Cerebral Atrophy? A Retrospective Evaluation

Background

Our purpose was to study the association between the intracranial atherosclerosis as measured by cavernous carotid artery calcification (ICAC) observed on head CT and atrophic changes of supra-tentorial brain demonstrated by MRI.

Methods

Institutional review board approval was obtained for this retrospective study incorporating 65 consecutive patients presenting acutely who had both head CT and MRI. Arterial calcifications of the intracranial cavernous carotids (ICAC) were assigned a number (1 to 4) in the bone window images from CT scans. These 4 groups were then combined into high (grades 3 and 4) and low calcium (grades 1 and 2) subgroups. Brain MRI was independently evaluated to identify cortical and central atrophy. Demographics and cardiovascular risk factors were evaluated in subjects with high and low ICAC. Relationship between CT demonstrated ICAC and brain atrophy patterns were evaluated both without and with adjustment for cerebral ischemic scores and cardiovascular risk factors.

Results

Forty-six of the 65 (71%) patients had high ICAC on head CT. Subjects with high ICAC were older, and had higher prevalence of hypertension, diabetes, coronary artery disease (CAD), atrial fibrillation and history of previous stroke (CVA) compared to those with low ICAC. Age demonstrated strong correlation with both supratentorial atrophy patterns. There was no correlation between ICAC and cortical atrophy. There was correlation however between central atrophy and ICAC. This persisted even after adjustment for age.

Conclusion

Age is the most important determinant of atrophic cerebral changes. However, high ICAC demonstrated age independent association with central atrophy.

     

Is There a Role for Risk Assessment within Precautionary Legislation?

Posing the question of whether the precautionary principle has a role in risk assessment effectively constrains any debate of the issue within a framework predicated on the assumption that application of risk assessment is inevitable in the formulation of regulatory decisions. The question can equally validly be expressed in terms of whether there is a role for risk assessment in the formulation of precautionary legislation. This allows the debate then to turn on consideration of two questions: Firstly, does the precautionary principle have a role in policy development? and secondly, is this role consistent and compatible with a risk based approach to regulation? When recast in these terms, a more holistic comparison of the aims and objectives of both approaches and of their relative power in the formulation of regulation becomes possible. This leads to the conclusion that the precautionary principle is, when defined and applied correctly, scientifically more robust than risk assessment. Precautionary approaches utilize scientific information and conform robustly to a scientific process but also explicitly incorporate indeterminacies into the decision making framework. Moreover, the precautionary principle when applied to environmental regulation, is more likely to lead to regulation consistent with global sustainability. On this premise, this paper argues that risk based approaches are essentially incompatible with approaches based on the precautionary paradigm, and that of the two, risk assessment is more likely to lead to unsustainable underprotection of the environment.     

Is Opium a Real Risk Factor for Esophageal Cancer or Just a Methodological Artifact? Hospital and Neighborhood Controls in Case-Control Studies

Background

Control selection is a major challenge in epidemiologic case-control studies. The aim of our study was to evaluate using hospital versus neighborhood control groups in studying risk factors of esophageal squamous cell carcinoma (ESCC).

Methodology/Principal Findings

We compared the results of two different case-control studies of ESCC conducted in the same region by a single research group. Case definition and enrollment were the same in the two studies, but control selection differed. In the first study, we selected two age- and sex-matched controls from inpatient subjects in hospitals, while for the second we selected two age- and sex-matched controls from each subject''s neighborhood of residence. We used the test of heterogeneity to compare the results of the two studies. We found no significant differences in exposure data for tobacco-related variables such as cigarette smoking, chewing Nass (a tobacco product) and hookah (water pipe) usage, but the frequency of opium usage was significantly different between hospital and neighborhood controls. Consequently, the inference drawn for the association between ESCC and tobacco use did not differ between the studies, but it did for opium use. In the study using neighborhood controls, opium use was associated with a significantly increased risk of ESCC (adjusted OR 1.77, 95% CI 1.17–2.68), while in the study using hospital controls, this was not the case (OR 1.09, 95% CI 0.63–1.87). Comparing the prevalence of opium consumption in the two control groups and a cohort enrolled from the same geographic area suggested that the neighborhood controls were more representative of the study base population for this exposure.

Conclusions/Significance

Hospital and neighborhood controls did not lead us to the same conclusion for a major hypothesized risk factor for ESCC in this population. Our results show that control group selection is critical in drawing appropriate conclusions in observational studies.     

What Is the Economic Case for Treating Obesity?

From both societal and payer perspectives, the economic effect of obesity in the United States is substantial, estimated at approximately 6% of our national health expenditure and cost of care in a major health maintenance organization. The number of physician visits related to obesity has increased 88% in a 6-year period. The morbidity cost (lost productivity) and functional capability of the patient with obesity is increasing rapidly (50% increase in lost productivity, 36% increase in restricted activity, and 28% increase in number of bed-days). Cost savings of treating obesity are comparable to those of treating other chronic diseases such as coronary heart disease and diabetes. Most studies indicate that most of the direct health care costs of obesity are from type 2 diabetes, coronary heart disease and hypertension. To date, however, there have been no published reports of the cost effectiveness of the medical management of obesity treatment. In conclusion, the cost of obesity is comparable to that of other chronic diseases, yet it receives disproportionately less attention. Cost effectiveness studies need to be initiated promptly.     

Is the Cytosolic Pi Concentration a Limiting Factor for Plant Cell Respiration?

The substrate-dependent O₂ uptake by sycamore (Acer pseudoplatanus L.) cell mitochondria in the presence of ADP and limiting Pi concentrations has been measured. The Pi concentration for half-maximum O₂ uptake rate was found to be in the range 20 to 50 micromolar for all the substrates tested. ³¹P NMR of intact sycamore cells indicated that the Pi concentration in the cytoplasm was in the range 5 to 6 millimolar, approximately 100-fold higher than the Pi concentration required for maximum O₂ uptake rates by isolated mitochondria. When sycamore cells were transferred to a culture medium devoid of Pi, the cytoplasmic Pi concentration decreased from 6 to less than 3 millimolar, but the intact cell respiration remained practically constant for at least 4 days. These results strongly suggest that, in vivo, the respiration rate of sycamore cells is not limited by the quantity of Pi supplied to the mitochondria.     

Is Ritonavir-Boosted Atazanavir a Risk for Cholelithiasis Compared to Other Protease Inhibitors?

Objective

To compare the incidence of complicated cholelithiasis in patients receiving ritonavir-boosted atazanavir (ATV/r)- containing antiretroviral therapy with those on other protease inhibitors (PIs).

Design

We conducted a single-center retrospective cohort study of patients who started either ritonavir-boosted ATV/r- or other PIs (ritonavir-boosted fosamprenavir, unboosted fosamprenavir, lopinavir/ritonavir, and ritonavir-boosted darunavir) -containing antiretroviral therapy.

Methods

The incidence of complicated cholelithiasis was determined in each group. Complicated cholelithiasis was defined as follows: 1) cholelithiasis complicated by cholecystitis, cholangitis, or pancreatitis or 2) symptomatic cholelithiasis or choledocholithiasis which required invasive procedures such as cholecystomy and endoscopic retrograde cholangiopancreatography. The effects of ATV/r were estimated by univariate and multivariate Cox hazards models as the primary exposure.

Results

Complicated cholelithiasis was diagnosed in 3 patients (2.23 per 1000 person-years) in the ATV/r group (n = 466), and 3 (1.64 per 1000 person-years) in the other PIs group (n = 776), respectively. The incidence was not statistically different in the two groups by log-rank test (P = 0.702). By univariate and multivariate analysis adjusted for age and body weight, ATV/r use was not associated with cholelithiasis. (HR = 1.365; 95% CI, 0.275–6.775; p = 0.704) (adjusted HR = 1.390; 95% CI, 0.276–7.017; p = 0.690). For the 3 patients who developed cholelithiasis in the ATV/r group, the time to the diagnosis of cholelithiasis was 18, 34, and 39 months, respectively.

Conclusion

In this study, the incidence of complicated cholelithiasis was low and was not different between patients on ATV/r and those on other PIs. On the contrary to ATV/r-associated nephrolithiasis, the possible risk of cholelithiasis should not preclude the use of ATV/r.     

The Risk Factors for Failure of an Upper Extremity Replantation: Is the Use of Cigarettes/Tobacco a Significant Factor?

Background

The purpose of this study was to explore the potential risk factors associated with the failure of an upper extremity replantation with a focus on cigarette or tobacco use.

Patients and Methods

A cohort of 102 patients with 149 replants (6 extremities, 143 digits) and a mean age of 41 years (range 5 to 72 years) was enrolled in this study. The data collected included age, gender, tobacco/cigarettes use, trauma mechanism, underlying disease (e.g., hypertension (HTN), diabetes mellitus (DM), etc.), and vein graft use. An analysis with a multivariable regression was conducted to identify the risk factors of replant failure and their respective odds ratios (ORs).

Results

Multilevel generalized linear mixed models (GLMMs) with a binomial distribution and logit link showed that smoking did not increase the risk of replant failure (p = 0.234). In addition, the survival of replants was not affected by DM or HTN (p = 0.285 and 0.938, respectively). However, the replantation results were significantly affected by the age of the patients and the mechanism of injury. Patients older than 50 years and those with avulsion or crush injuries tended to have a higher risk of replant failure (OR = 2.29, 6.45, and 5.42, respectively; p = 0.047, 0.028, and 0.032, respectively).

Conclusions

This study showed that the use of cigarettes/tobacco did not affect the replantation outcome. The main risks for replant failure included being older than 50 years and the trauma mechanism (avulsion or crush injuries).     

How Safe Is Safe Enough? Radiation Risk for a Human Mission to Mars

Astronauts on a mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR) — made up of high-energy protons and high charge (Z) and energy (E) (HZE) nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth''s magnetosphere and solid body are lost. NASA''s radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID) at the upper 95% confidence interval (CI) of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space missions. Using NASA''s models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars mission. Additional risks to the central nervous system (CNS) and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate.     

Is Having Sex with Other Men a Risk Factor for Transfusion-Transmissible Infections in Male Blood Donors in Western Countries? A Systematic Review

Background

Although increased prevalence of transfusion transmissible infections (TTI) among “men who have sex with men” (MSM) has been well documented, the exclusion of MSM as blood donors is contested. The aim of this systematic review is to find studies that describe the risk of TTI in MSM blood donors.

Methods

We searched MEDLINE, Embase, The Cochrane Central Register of Controlled Trials, Cinahl, and Web of Science, and used GRADE for determining evidence quality. We included studies comparing MSM and non-MSM blood donors (or people eligible to give blood), living in areas most relevant for our Blood Service.

Results

Out of 18 987 articles, 14 observational studies were included. Two studies directly compared MSM with non-MSM donors showing that MSM donors have a statistically significant higher risk of HIV-1 infections. In one of these studies it was shown that this was related to recent (< 12 months) MSM contact. In two additional studies no evidence was shown in favour of a certain deferral period for MSM. Ten studies, applying permanent deferral for MSM, compared infected versus non-infected donors. One study found that MSM is a statistically significant risk factor for HIV-1 infection in blood donors. For other TTI such as HBV or HCV, an increased risk of infection could not be demonstrated, because the precision of the results was affected by the low numbers of donors with MSM as risk factor, or because of risk of bias in the included studies. All studies included low level evidence, because of risk of bias and imprecision of the results.

Conclusions

High-quality studies investigating the risk of TTI in MSM who donate blood are scarce. The available evidence suggests a link between MSM blood donors and HIV-1 infection, but is too limited to be able to unambiguously/clearly recommend a certain deferral policy.