Showing papers by "Veterans Health Administration published in 2004"

The medial temporal lobe

Abstract: The medial temporal lobe includes a system of anatomically related structures that are essential for declarative memory (conscious memory for facts and events). The system consists of the hippocampal region (CA fields, dentate gyrus, and subicular complex) and the adjacent perirhinal, entorhinal, and parahippocampal cortices. Here, we review findings from humans, monkeys, and rodents that illuminate the function of these structures. Our analysis draws on studies of human memory impairment and animal models of memory impairment, as well as neurophysiological and neuroimaging data, to show that this system (a) is principally concerned with memory, (b) operates with neocortex to establish and maintain long-term memory, and (c) ultimately, through a process of consolidation, becomes independent of long-term memory, though questions remain about the role of perirhinal and parahippocampal cortices in this process and about spatial memory in rodents. Data from neurophysiology, neuroimaging, and neuroanatomy point to a division of labor within the medial temporal lobe. However, the available data do not support simple dichotomies between the functions of the hippocampus and the adjacent medial temporal cortex, such as associative versus nonassociative memory, episodic versus semantic memory, and recollection versus familiarity.

Delirium as a predictor of mortality in mechanically ventilated patients in the intensive care unit

Abstract: ContextIn the intensive care unit (ICU), delirium is a common yet underdiagnosed form of organ dysfunction, and its contribution to patient outcomes is unclear.ObjectiveTo determine if delirium is an independent predictor of clinical outcomes, including 6-month mortality and length of stay among ICU patients receiving mechanical ventilation.Design, Setting, and ParticipantsProspective cohort study enrolling 275 consecutive mechanically ventilated patients admitted to adult medical and coronary ICUs of a US university-based medical center between February 2000 and May 2001. Patients were followed up for development of delirium over 2158 ICU days using the Confusion Assessment Method for the ICU and the Richmond Agitation-Sedation Scale.Main Outcome MeasuresPrimary outcomes included 6-month mortality, overall hospital length of stay, and length of stay in the post-ICU period. Secondary outcomes were ventilator-free days and cognitive impairment at hospital discharge.ResultsOf 275 patients, 51 (18.5%) had persistent coma and died in the hospital. Among the remaining 224 patients, 183 (81.7%) developed delirium at some point during the ICU stay. Baseline demographics including age, comorbidity scores, dementia scores, activities of daily living, severity of illness, and admission diagnoses were similar between those with and without delirium (P>.05 for all). Patients who developed delirium had higher 6-month mortality rates (34% vs 15%, P = .03) and spent 10 days longer in the hospital than those who never developed delirium (P<.001). After adjusting for covariates (including age, severity of illness, comorbid conditions, coma, and use of sedatives or analgesic medications), delirium was independently associated with higher 6-month mortality (adjusted hazard ratio [HR], 3.2; 95% confidence interval [CI], 1.4-7.7; P = .008), and longer hospital stay (adjusted HR, 2.0; 95% CI, 1.4-3.0; P<.001). Delirium in the ICU was also independently associated with a longer post-ICU stay (adjusted HR, 1.6; 95% CI, 1.2-2.3; P = .009), fewer median days alive and without mechanical ventilation (19 [interquartile range, 4-23] vs 24 [19-26]; adjusted P = .03), and a higher incidence of cognitive impairment at hospital discharge (adjusted HR, 9.1; 95% CI, 2.3-35.3; P = .002).ConclusionDelirium was an independent predictor of higher 6-month mortality and longer hospital stay even after adjusting for relevant covariates including coma, sedatives, and analgesics in patients receiving mechanical ventilation.

Modulation of NF-κB-dependent transcription and cell survival by the SIRT1 deacetylase

Abstract: NF‐κB is responsible for upregulating gene products that control cell survival. In this study, we demonstrate that SIRT1, a nicotinamide adenosine dinucleotide‐dependent histone deacetylase, regulates the transcriptional activity of NF‐κB. SIRT1, the mammalian ortholog of the yeast SIR2 (Silencing Information Regulator) and a member of the Sirtuin family, has been implicated in modulating transcriptional silencing and cell survival. SIRT1 physically interacts with the RelA/p65 subunit of NF‐κB and inhibits transcription by deacetylating RelA/p65 at lysine 310. Treatment of cells with resveratrol, a small‐molecule agonist of Sirtuin activity, potentiates chromatin‐associated SIRT1 protein on the cIAP‐2 promoter region, an effect that correlates with a loss of NF‐κB‐regulated gene expression and sensitization of cells to TNFα‐induced apoptosis. While SIRT1 is capable of protecting cells from p53‐induced apoptosis, our work provides evidence that SIRT1 activity augments apoptosis in response to TNFα by the ability of the deacetylase to inhibit the transactivation potential of the RelA/p65 protein.

Measuring experiential avoidance: A preliminary test of a working model

Abstract: The present study describes the development of a short, general measure of experiential avoidance, based on a specific theoretical approach to this process. A theoretically driven iterative exploratory analysis using structural equation modeling on data from a clinical sample yielded a single factor comprising 9 items. A fully confirmatory factor analysis upheld this same 9-item factor in an independent clinical sample. The operational characteristics of the Acceptance and Action Questionnaire (AAQ) were then examined in 8 additional samples. All totaled, over 2,400 participants were studied. As expected, higher levels of experiential avoidance were associated with higher levels of general psychopathology, depression, anxiety, a variety of specific fears, trauma, and a lower quality of life. The AAQ related to more specific measures of avoidant coping and to self-deceptive positivity, but the relation to psychopathology could not be fully accounted for by these alternative measures. The data provide some initial support for the model of experiential avoidance based on Relational Frame Theory that is incorporated into Acceptance and Commitment Therapy, and provides researchers with a preliminary measure for use in population-based studies on experiential avoidance.

Prophylactic Defibrillator Implantation in Patients with Nonischemic Dilated Cardiomyopathy

Abstract: background Patients with nonischemic dilated cardiomyopathy are at substantial risk for sudden death from cardiac causes. However, the value of prophylactic implantation of an implantable cardioverter–defibrillator (ICD) to prevent sudden death in such patients is unknown. methods We enrolled 458 patients with nonischemic dilated cardiomyopathy, a left ventricular ejection fraction of less than 36 percent, and premature ventricular complexes or nonsustained ventricular tachycardia. A total of 229 patients were randomly assigned to receive standard medical therapy, and 229 to receive standard medical therapy plus a single-chamber ICD. results Patients were followed for a mean (±SD) of 29.0±14.4 months. The mean left ventricular ejection fraction was 21 percent. The vast majority of patients were treated with angiotensin-converting–enzyme (ACE) inhibitors (86 percent) and beta-blockers (85 percent). There were 68 deaths: 28 in the ICD group, as compared with 40 in the standard-therapy group (hazard ratio, 0.65; 95 percent confidence interval, 0.40 to 1.06; P=0.08). The mortality rate at two years was 14.1 percent in the standard-therapy group (annual mortality rate, 7 percent) and 7.9 percent in the ICD group. There were 17 sudden deaths from arrhythmia: 3 in the ICD group, as compared with 14 in the standardtherapy group (hazard ratio, 0.20; 95 percent confidence interval, 0.06 to 0.71; P=0.006). conclusions In patients with severe, nonischemic dilated cardiomyopathy who were treated with ACE inhibitors and beta-blockers, the implantation of a cardioverter–defibrillator significantly reduced the risk of sudden death from arrhythmia and was associated with a nonsignificant reduction in the risk of death from any cause.

Combination of isosorbide dinitrate and hydralazine in blacks with heart failure.

Abstract: background We examined whether a fixed dose of both isosorbide dinitrate and hydralazine provides additional benefit in blacks with advanced heart failure, a subgroup previously noted to have a favorable response to this therapy. methods A total of 1050 black patients who had New York Heart Association class III or IV heart failure with dilated ventricles were randomly assigned to receive a fixed dose of isosorbide dinitrate plus hydralazine or placebo in addition to standard therapy for heart failure. The primary end point was a composite score made up of weighted values for death from any cause, a first hospitalization for heart failure, and change in the quality of life. results The study was terminated early owing to a significantly higher mortality rate in the placebo group than in the group given isosorbide dinitrate plus hydralazine (10.2 percent vs. 6.2 percent, P = 0.02). The mean primary composite score was significantly better in the group given isosorbide dinitrate plus hydralazine than in the placebo group (i0.1±1.9 vs. i0.5±2.0, P=0.01; range of possible values, –6 to +2), as were its individual components (43 percent reduction in the rate of death from any cause [hazard ratio, 0.57; P=0.01] 33 percent relative reduction in the rate of first hospitalization for heart failure [16.4 percent vs. 22.4 percent, P=0.001], and an improvement in the quality of life [change in score, i5.6±20.6 vs. i2.7±21.2, with lower scores indicating better quality of life; P=0.02; range of possible values, 0 to 105]). conclusions The addition of a fixed dose of isosorbide dinitrate plus hydralazine to standard therapy for heart failure including neurohormonal blockers is efficacious and increases survival among black patients with advanced heart failure.

DNA Methylation and Cancer

Abstract: DNA methylation is an important regulator of gene transcription, and its role in carcinogenesis has been a topic of considerable interest in the last few years. Alterations in DNA methylation are common in a variety of tumors as well as in development. Of all epigenetic modifications, hypermethylation, which represses transcription of the promoter regions of tumor suppressor genes leading to gene silencing, has been most extensively studied. However, global hypomethylation has also been recognized as a cause of oncogenesis. New information concerning the mechanism of methylation and its control has led to the discovery of many regulatory proteins and enzymes. The contribution of dietary folate and methylene terahydrofolate reductase polymorphisms to methylation patterns in normal and cancer tissues is under intense investigation. As methylation occurs early and can be detected in body fluids, it may be of potential use in early detection of tumors and for determining the prognosis. Because DNA methylation...

Management of diabetes and hyperglycemia in hospitals.

Abstract: Diabetes increases the risk for disorders that predispose individuals to hospitalization, including coronary artery, cerebrovascular and peripheral vascular disease, nephropathy, infection, and lower-extremity amputations. The management of diabetes in the hospital is generally considered secondary in importance compared with the condition that prompted admission. Recent studies (1,2) have focused attention to the possibility that hyperglycemia in the hospital is not necessarily a benign condition and that aggressive treatment of diabetes and hyperglycemia results in reduced mortality and morbidity. The purpose of this technical review is to evaluate the evidence relating to the management of hyperglycemia in hospitals, with particular focus on the issue of glycemic control and its possible impact on hospital outcomes. The scope of this review encompasses adult nonpregnant patients who do not have diabetic ketoacidosis or hyperglycemic crises. For the purposes of this review, the following terms are defined (adapted from the American Diabetes Association [ADA] Expert Committee on the Diagnosis and Classification of Diabetes Mellitus) (3): The prevalence of diabetes in hospitalized adult patients is not known. In the year 2000, 12.4% of hospital discharges in the U.S. listed diabetes as a diagnosis. The average length of stay was 5.4 days (4). Diabetes was the principal diagnosis in only 8% of these hospitalizations. The accuracy of using hospital discharge diagnosis codes for identifying patients with …

Coronary-Artery Revascularization before Elective Major Vascular Surgery

Abstract: Background The benefit of coronary-artery revascularization before elective major vascular surgery is unclear. Methods We randomly assigned patients at increased risk for perioperative cardiac complications and clinically significant coronary artery disease to undergo either revascularization or no revascularization before elective major vascular surgery. The primary end point was long-term mortality. Results Of 5859 patients scheduled for vascular operations at 18 Veterans Affairs medical centers, 510 (9 percent) were eligible for the study and were randomly assigned to either coronary-artery revascularization before surgery or no revascularization before surgery. The indications for a vascular operation were an expanding abdominal aortic aneurysm (33 percent) or arterial occlusive disease of the legs (67 percent). Among the patients assigned to preoperative coronary-artery revascularization, percutaneous coronary intervention was performed in 59 percent, and bypass surgery was performed in 41 percent. T...

Interventions for the prevention of falls in older adults: systematic review and meta-analysis of randomised clinical trials

Abstract: Objective To assess the relative effectiveness of interventions to prevent falls in older adults to either a usual care group or control group. Design Systematic review and meta-analyses. Data sources Medline, HealthSTAR, Embase, the Cochrane Library, other health related databases, and the reference lists from review articles and systematic reviews. Data extraction Components of falls intervention: multifactorial falls risk assessment with management programme, exercise, environmental modifications, or education. Results 40 trials were identified. A random effects analysis combining trials with risk ratio data showed a reduction in the risk of falling (risk ratio 0.88, 95% confidence interval 0.82 to 0.95), whereas combining trials with incidence rate data showed a reduction in the monthly rate of falling (incidence rate ratio 0.80, 0.72 to 0.88). The effect of individual components was assessed by meta-regression. A multifactorial falls risk assessment and management programme was the most effective component on risk of falling (0.82, 0.72 to 0.94, number needed to treat 11) and monthly fall rate (0.63, 0.49 to 0.83; 11.8 fewer falls in treatment group per 100 patients per month). Exercise interventions also had a beneficial effect on the risk of falling (0.86, 0.75 to 0.99, number needed to treat 16) and monthly fall rate (0.86, 0.73 to 1.01; 2.7). Conclusions Interventions to prevent falls in older adults are effective in reducing both the risk of falling and the monthly rate of falling. The most effective intervention was a multifactorial falls risk assessment and management programme. Exercise programmes were also effective in reducing the risk of falling.

The empirical status of empirically supported psychotherapies: assumptions, findings, and reporting in controlled clinical trials.

Abstract: This article provides a critical review of the assumptions and findings of studies used to establish psychotherapies as empirically supported. The attempt to identify empirically supported therapies (ESTs) imposes particular assumptions on the use of randomized controlled trial (RCT) methodology that appear to be valid for some disorders and treatments (notably exposure-based treatments of specific anxiety symptoms) but substantially violated for others. Meta-analytic studies support a more nuanced view of treatment efficacy than implied by a dichotomous judgment of supported versus unsupported. The authors recommend changes in reporting practices to maximize the clinical utility of RCTs, describe alternative methodologies that may be useful when the assumptions underlying EST methodology are violated, and suggest a shift from validating treatment packages to testing intervention strategies and theories of change that clinicians can integrate into empirically informed therapies.

Diagnosis and Treatment of Diabetic Foot Infections

Abstract: Benjamin A. Lipsky, Anthony R. Berendt, H. Gunner Deery, John M. Embil, Warren S. Joseph, Adolf W. Karchmer, Jack L. LeFrock, Daniel P. Lew, Jon T. Mader, Carl Norden, and James S. Tan Medical Service, Veterans Affairs Puget Sound Health Care System, and Division of General Internal Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington; Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford, United Kingdom; Northern Michigan Infectious Diseases, Petoskey, Michigan; Section of Infectious Diseases, Department of Medicine, University of Manitoba, Winnipeg, Manitoba; Section of Podiatry, Department of Primary Care, Veterans Affairs Medical Center, Coatesville, Pennsylvania; Division of Infectious Diseases, Department of Medicine, Harvard Medical School, and Beth Israel Deaconess Medical Center, Boston, Massachusetts; Dimensional Dosing Systems, Sarasota, Florida; Department of Medicine, Service of Infectious Diseases, University of Geneva Hospitals, Geneva, Switzerland; Department of Internal Medicine, The Marine Biomedical Institute, and Department of Orthopaedics and Rehabilitation, University of Texas Medical Branch, Galveston, Texas; Department of Medicine, New Jersey School of Medicine and Dentistry, and Cooper Hospital, Camden, New Jersey; and Department of Internal Medicine, Summa Health System, and Northeastern Ohio Universities College of Medicine, Akron, Ohio

Small interfering RNA-induced transcriptional gene silencing in human cells.

Abstract: Small interfering RNA (siRNA) and microRNA silence genes at the transcriptional, posttranscriptional, and/or translational level. Using human tissue culture cells, we show that promoter-directed siRNA inhibits transcription of an integrated, proviral, elongation factor 1alpha (EF1A) promoter-green fluorescent protein reporter gene and of endogenous EF1A. Silencing was associated with DNA methylation of the targeted sequence, and it required either active transport of siRNA into the nucleus or permeabilization of the nuclear envelope by lentiviral transduction. These results demonstrate that siRNA-directed transcriptional silencing is conserved in mammals, providing a means to inhibit mammalian gene function.

Spatial memory, recognition memory, and the hippocampus

Abstract: There is wide agreement that spatial memory is dependent on the integrity of the hippocampus, but the importance of the hippocampus for nonspatial tasks, including tasks of object recognition memory is not as clear. We examined the relationship between hippocampal lesion size and both spatial memory and object recognition memory in rats. Spatial memory was impaired after bilateral dorsal hippocampal lesions that encompassed 30-50% total volume, and as lesion size increased from 50% to ≈100% of total hippocampal volume, performance was similarly impaired. In contrast, object recognition was intact after dorsal hippocampal lesions that damaged 50-75% of total hippocampal volume and was impaired only after larger lesions that encompassed 75-100% of hippocampal volume. Last, ventral hippocampal lesions that encompassed ≈50% of total hippocampal volume impaired spatial memory but did not affect object recognition memory. These findings show that the hippocampus is important for both spatial memory and recognition memory. However, spatial memory performance requires more hippocampal tissue than does recognition memory.

Derivation of Research Diagnostic Criteria for Insomnia: Report of an American Academy of Sleep Medicine Work Group

Abstract: Insomnia is a highly prevalent, often debilitating, and economically burdensome form of sleep disturbance caused by various situational, medical, emotional, environmental and behavioral factors. Although several consensually-derived nosologies have described numerous insomnia phenotypes, research concerning these phenotypes has been greatly hampered by a lack of widely accepted operational research diagnostic criteria (RDC) for their definition. The lack of RDC has, in turn, led to inconsistent research findings for most phenotypes largely due to the variable definitions used for their ascertainment. Given this problem, the American Academy of Sleep Medicine (AASM) commissioned a Work Group (WG) to review the literature and identify those insomnia phenotypes that appear most valid and tenable. In addition, this WG was asked to derive standardized RDC for these phenotypes and recommend assessment procedures for their ascertainment. This report outlines the WG's findings, the insomnia RDC derived, and research assessment procedures the WG recommends for identifying study participants who meet these RDC.

Multiple-center, randomized, placebo-controlled, double-blind study of the nitric oxide synthase inhibitor 546C88: Effect on survival in patients with septic shock*

Abstract: Objective: To assess the safety and efficacy of the nitric oxide synthase inhibitor 546C88 in patients with septic shock. The predefined primary efficacy objective was survival at day 28. Design: Multiple-center, randomized, two-stage, double-blind, placebo-controlled, safety and efficacy study. Setting: A total of 124 intensive care units in Europe, North America, South America, South Africa, and Australasia. Patients: A total of 797 patients with septic shock diagnosed for <24 hrs. Interventions: Patients with septic shock were allocated to receive 546C88 or placebo (5% dextrose) for up to 7 days (stage 1) or 14 days (stage 2) in addition to conventional therapy. Study drug was initiated at 0.05 mL·kg 1 ·hr 1 (2.5 mg·kg 1 ·hr 1 546C88) and titrated up to a maximum rate of 0.4 mL·kg 1 ·hr 1 to maintain mean arterial pressure between 70 and 90 mm Hg while attempting to withdraw concurrent vasopressors. Measurements and Main Results: Hemodynamic variables, organ function data, microbiological data, concomitant therapy, and adverse event data were recorded at baseline, throughout treatment, and at follow-up. The primary end point was day-28 survival. The trial was stopped early after review by the independent data safety monitoring board. Day-28 mortality was 59% (259/439) in the 546C88 group and 49% (174/358) in the placebo group (p < .001). The overall incidence of adverse events was similar in both groups, although a higher proportion of the events was considered possibly attributable to study drug in the 546C88 group. Most of the events accounting for the disparity between the groups were associated with the cardiovascular system (e.g., decreased cardiac output, pulmonary hypertension, systemic arterial hypertension, heart failure). The causes of death in the study were consistent with those expected in patients with septic shock, although there was a higher proportion of cardiovascular deaths and a lower incidence of deaths caused by multiple organ failure in the 546C88 group. Conclusions: In this study, the nonselective nitric oxide synthase inhibitor 546C88 increased mortality in patients with septic shock. (Crit Care Med 2004; 32:21‐30)

Open mesh versus laparoscopic mesh repair of inguinal hernia

Abstract: BACKGROUND Repair of inguinal hernias in men is a common surgical procedure, but the most effective surgical technique is unknown. METHODS We randomly assigned men with inguinal hernias at 14 Veterans Affairs (VA) medical centers to either open mesh or laparoscopic mesh repair. The primary outcome was recurrence of hernias at two years. Secondary outcomes included complications and patient-centered outcomes. RESULTS Of the 2164 patients who were randomly assigned to one of the two procedures, 1983 underwent an operation; two-year follow-up was completed in 1696 (85.5 percent). Recurrences were more common in the laparoscopic group (87 of 862 patients [10.1 percent]) than in the open group (41 of 834 patients [4.9 percent]; odds ratio, 2.2; 95 percent confidence interval, 1.5 to 3.2). The rate of complications was higher in the laparoscopic-surgery group than in the open-surgery group (39.0 percent vs. 33.4 percent; adjusted odds ratio, 1.3; 95 percent confidence interval, 1.1 to 1.6). The laparoscopic-surgery group had less pain initially than the open-surgery group on the day of surgery (difference in mean score on a visual-analogue scale, 10.2 mm; 95 percent confidence interval, 4.8 to 15.6) and at two weeks (6.1 mm; 95 percent confidence interval, 1.7 to 10.5) and returned to normal activities one day earlier (adjusted hazard ratio for a shorter time to return to normal activities, 1.2; 95 percent confidence interval, 1.1 to 1.3). In prespecified analyses, there was a significant interaction between the surgical approach (open or laparoscopic) and the type of hernia (primary or recurrent) (P=0.012). Recurrence was significantly more common after laparoscopic repair than after open repair of primary hernias (10.1 percent vs. 4.0 percent), but rates of recurrence after repair of recurrent hernias were similar in the two groups (10.0 percent and 14.1 percent, respectively). CONCLUSIONS The open technique is superior to the laparoscopic technique for mesh repair of primary hernias.

Social supports and serotonin transporter gene moderate depression in maltreated children.

Abstract: In this study, measures of the quality and availability of social supports were found to moderate risk for depression associated with a history of maltreatment and the presence of the short (s) allele of the serotonin transporter gene promoter polymorphism (5-HTTLPR). The present investigation (i) replicates research in adults showing that 5-HTTLPR variation moderates the development of depression after stress, (ii) extends the finding to children, and (iii) demonstrates the ability of social supports to further moderate risk for depression. Maltreated children with the s/s genotype and no positive supports had the highest depression ratings, scores that were twice as high as the non-maltreated comparison children with the same genotype. However, the presence of positive supports reduced risk associated with maltreatment and the s/s genotype, such that maltreated children with this profile had only minimal increases in their depression scores. These findings are consistent with emerging preclinical and clinical data suggesting that the negative sequelae associated with early stress are not inevitable. Risk for negative outcomes may be modified by both genetic and environmental factors, with the quality and availability of social supports among the most important environmental factors in promoting resiliency in maltreated children, even in the presence of a genotype expected to confer vulnerability for psychiatric disorder.

Endogenous ligands of Toll-like receptors

Abstract: Extensive work has suggested that a number of endogenous molecules such as heat shock proteins (hsp) may be potent activators of the innate immune system capable of inducing proinflammatory cytokine production by the monocyte-macrophage system and the activation and maturation of dendritic cells. The cytokine-like effects of these endogenous molecules are mediated via the Toll-like receptor (TLR) signal-transduction pathways in a manner similar to lipopolysaccharide (LPS; via TLR4) and bacterial lipoproteins (via TLR2). However, recent evidence suggests that the reported cytokine effects of hsp may be a result of the contaminating LPS and LPS-associated molecules. The reasons for previous failure to recognize the contaminant(s) being responsible for the putative TLR ligands of hsp include failure to use highly purified hsp free of LPS contamination; failure to recognize the heat sensitivity of LPS; and failure to consider contaminant(s) other than LPS. Whether other reported putative endogenous ligands of TLR2 and TLR4 are a result of contamination of pathogen-associated molecular patterns is not clear. It is essential that efforts should be directed to conclusively determine whether the reported putative endogenous ligands of TLRs are a result of the endogenous molecules or of contaminant(s), before exploring further the implication and therapeutic potential of these putative TLR ligands.

Deficiency of carbohydrate response element-binding protein (ChREBP) reduces lipogenesis as well as glycolysis

Abstract: The liver provides for long-term energy needs of the body by converting excess carbohydrate into fat for storage. Insulin is one factor that promotes hepatic lipogenesis, but there is increasing evidence that glucose also contributes to the coordinated regulation of carbohydrate and fat metabolism in liver by mechanisms that are independent of insulin. In this study, we show that the transcription factor, carbohydrate response element-binding protein (ChREBP), is required both for basal and carbohydrate-induced expression of several liver enzymes essential for coordinated control of glucose metabolism, fatty acid, and the synthesis of fatty acids and triglycerides in vivo.

Effects of Resistance Training on Older Adults

Abstract: Using an integrative approach, this review highlights the benefits of resistance training toward improvements in functional status, health and quality of life among older adults. Sarcopenia (i.e. muscle atrophy) and loss of strength are known to occur with age. While its aetiology is poorly understood, the multifactorial sequelae of sarcopenia are well documented and present a major public health concern to our aging population, as both the quality of life and the likelihood of age-associated declines in health status are influenced. These age-related declines in health include decreased energy expenditure at rest and during exercise, and increased body fat and its accompanying increased dyslipidaemia and reduced insulin sensitivity. Quality of life is affected by reduced strength and endurance and increased difficulty in being physically active. Strength and muscle mass are increased following resistance training in older adults through a poorly understood series of events that appears to involve the recruitment of satellite cells to support hypertrophy of mature myofibres. Muscle quality (strength relative to muscle mass) also increases with resistance training in older adults possibly for a number of reasons, including increased ability to neurally activate motor units and increased high-energy phosphate availability. Resistance training in older adults also increases power, reduces the difficulty of performing daily tasks, enhances energy expenditure and body composition, and promotes participation in spontaneous physical activity. Impairment in strength development may result when aerobic training is added to resistance training but can be avoided with training limited to 3 days/week.