Exercise in Dialysis: Ready for Prime Time?

It is widely acknowledged that patients with end-stage kidney disease receiving maintenance hemodialysis (HD) may benefit from increasing their physical activity levels. Decades of exercise-related clinical trials have demonstrated improvements in various metrics related to dialysis patient's health and quality of life. Yet, the implementation of exercise programs in dialysis clinics today is scarce, and physical inactivity and dysfunction remain a hallmark of the disease. To address this issue, many groups worldwide are beginning to rethink how physical activity and exercise are prescribed in HD patients, as well as how to evaluate the efficacy of these programs. The vast majority of exercise interventions in HD patients have included intradialytic cycling as the predominant or only exercise prescription. Moreover, efficacy has most often been evaluated using standard measures of strength, physical function, and/or traditional cardiovascular disease risk factors (e.g., blood pressure, lipids, etc.). More recently, there has been a greater emphasis on novel intervention approaches that are focused on providing patients with a greater variety of options for exercise and enhanced motivational tools. The benefits of exercise on patient reported outcome measures (PROMs) and other clinically important outcomes are also becoming more prevalent. The purpose of this review was to: (1) critically review the data from several recently published large randomized clinical trials of exercise in HD patients, (2) discuss some of the novel approaches that groups across the world are taking to improve implementation and efficacy of exercise-related interventions in HD, and (3) discuss policy prescriptions that may be needed to continue improving exercise prescriptions for this critically ill patient population. While it may be too early to declare that exercise in dialysis is ready for prime time, exciting advances have been made in recent years, yet more work is needed to realize its full potential.

Accuracy of FDG-PET to diagnose lung cancer in areas with infectious lung disease: a meta-analysis.

IMPORTANCE: Positron emission tomography (PET) combined with fludeoxyglucose F 18 (FDG) is recommended for the noninvasive diagnosis of pulmonary nodules suspicious for lung cancer. In populations with endemic infectious lung disease, FDG-PET may not accurately identify malignant lesions. OBJECTIVES: To estimate the diagnostic accuracy of FDG-PET for pulmonary nodules suspicious for lung cancer in regions where infectious lung disease is endemic and compare the test accuracy in regions where infectious lung disease is rare. DATA SOURCES AND STUDY SELECTION: Databases of MEDLINE, EMBASE, and the Web of Science were searched from October 1, 2000, through April 28, 2014. Articles reporting information sufficient to calculate sensitivity and specificity of FDG-PET to diagnose lung cancer were included. Only studies that enrolled more than 10 participants with benign and malignant lesions were included. Database searches yielded 1923 articles, of which 257 were assessed for eligibility. Seventy studies were included in the analysis. Studies reported on a total of 8511 nodules; 5105 (60%) were malignant. DATA EXTRACTION AND SYNTHESIS: Abstracts meeting eligibility criteria were collected by a research librarian and reviewed by 2 independent reviewers. Hierarchical summary receiver operating characteristic curves were constructed. A random-effects logistic regression model was used to summarize and assess the effect of endemic infectious lung disease on test performance. MAIN OUTCOME AND MEASURES: The sensitivity and specificity for FDG-PET test performance. RESULTS: Heterogeneity for sensitivity (I2 = 87%) and specificity (I2 = 82%) was observed across studies. The pooled (unadjusted) sensitivity was 89% (95% CI, 86%-91%) and specificity was 75% (95% CI, 71%-79%). There was a 16% lower average adjusted specificity in regions with endemic infectious lung disease (61% [95% CI, 49%-72%]) compared with nonendemic regions (77% [95% CI, 73%-80%]). Lower specificity was observed when the analysis was limited to rigorously conducted and well-controlled studies. In general, sensitivity did not change appreciably by endemic infection status, even after adjusting for relevant factors. CONCLUSIONS AND RELEVANCE: The accuracy of FDG-PET for diagnosing lung nodules was extremely heterogeneous. Use of FDG-PET combined with computed tomography was less specific in diagnosing malignancy in populations with endemic infectious lung disease compared with nonendemic regions. These data do not support the use of FDG-PET to diagnose lung cancer in endemic regions unless an institution achieves test performance accuracy similar to that found in nonendemic regions.

Transcriptional remodeling of rapidly stimulated HL-1 atrial myocytes exhibits concordance with human atrial fibrillation.

During atrial fibrillation (AF), rapid stimulation causes atrial remodeling that increases arrhythmia susceptibility. Using an established atrial (HL-1) myocyte model, we investigated the transcriptional profile associated with early atrial myocyte remodeling. Spontaneously contracting HL-1 cells were cultured in the absence and presence of rapid stimulation for 24 h and RNA harvested for microarray analysis. We identified 758 genes that were significantly altered with rapid stimulation (626 up- and 132 down-regulated). Results were confirmed using real-time quantitative RT-PCR for selected genes based on physiological relevance in human AF and/or experimental atrial tachycardia (AT), and regulation in the microarray results. In some cases, transcriptional changes were rapid, occurring within 3 h. For a selected group of genes, results were validated for the expressed protein, with findings that correlated with observed transcriptional changes. Significantly regulated genes were classified using the Gene Ontology Database to permit direct comparison of our findings with previously published myocardial transcriptional profiles. For broad functional categories, there was strong concordance between rapidly stimulated HL-1 myocytes and human AF, but not for other remodeling paradigms (cardiomyopathy and exercise). Many individual gene changes were conserved with AF/AT, with marked up-regulation of genes encoding brain and atrial natriuretic peptide precursors, and heat shock proteins. For the conserved genes, both a cellular stress and survival response was evident. Our results demonstrate similarities with human AF/experimental AT with respect to large-scale patterns of transcriptional remodeling, as well as regulation of specific individual genes. Importantly, we identified novel pathways and molecules that were concordantly regulated in vivo.

Severe Sepsis and Acute Myocardial Dysfunction in an Adolescent with Chlamydia Trachomatis Pelvic Inflammatory Disease: A Case Report.

BACKGROUND: Although generally asymptomatic, severe Chlamydia trachomatis (C. trachomatis) infections have been documented. C. trachomatis has been associated with myocarditis as well as sepsis. CASE: A 19-year-old girl with type 1 diabetes mellitus developed sudden-onset mental status change and shock after resolution of diabetic ketoacidosis. Abdominal and pelvic imaging showed uterine and adnexal inflammation, and pelvic examination confirmed a diagnosis of pelvic inflammatory disease. The patient was intubated, required vasopressor support, and developed severe biventricular myocardial dysfunction. Infectious myocarditis workup was negative. Nucleic acid amplification testing from vaginal discharge was positive for C. trachomatis and Trichomonas vaginalis and negative for Neisseria gonorrhoeae. SUMMARY AND CONCLUSION: C. trachomatis should be considered in the workup of septic shock, particularly in populations at high risk for sexually transmitted infections.