Kidney Function

Background: Protein-energy wasting is common in chronic kidney disease and is associated with decreases in body muscle and fat stores and poor outcomes. The accuracy and reliability of field methods to measure body composition is unknown in this population.Study Design: Cross-sectional observational study.Setting & Participants: 118 maintenance hemodialysis patients were seen at the General Clinical Research Center at Harbor-UCLA Medical Center, Torrance, CA.Index Tests: Triceps skinfold, near-infrared interactance, and bioelectrical impedance analysis using the Segal, Kushner, and Lukaski equations.Reference Test: Dual-energy x-ray absorptiometry (DEXA).Results: Participants (42% women, 52% with diabetes, 40% African Americans, and 38% Hispanics) were aged 49.4 ± 11.5 (mean ± SD) years, and had undergone dialysis therapy for 41.1 ± 32.9 months. Body mass index was 27.0 ± 6.0 kg/m2. Using DEXA as the reference test, the bioelectrical impedance analysis–Kushner equation, triceps skinfold, and near-infrared interactance were most accurate of the index tests in estimating total-body fat percentage, whereas bioelectrical impedance analysis–Segal equation and bioelectrical impedance analysis–Lukaski equation overestimated total body fat percentage. Bland-Altman analyses and difference plots showed that bioelectrical impedance analysis–Kushner and near-infrared interactance were most similar to the reference test. Bioelectrical impedance analysis–Kushner, triceps skinfold, and near-infrared interactance had the smallest mean differences from DEXA, especially in women (1.6%, 0.7%, and 1.2%, respectively). Similar results were observed in African American participants (n = 47).Limitations: Measurements were performed 1 day after a hemodialysis treatment, leading to more fluid retention, which may have affected the reference and index tests differently.Conclusions: Using DEXA as the reference test, both near-infrared interactance and bioelectrical impedance analysis–Kushner method yield more consistent estimates of total body fat percentage in maintenance hemodialysis patients compared with the other index tests. Near-infrared interactance is not affected by skin color. Field methods with portable devices may provide adequate precision.

The incidence rate of acute kidney injury (AKI) is highest in elderly patients, who make up an ever-growing segment of the population at large. AKI in these patients is associated with an increased risk of short- and long-term death and chronic kidney disease, including end-stage renal disease. Whether AKI in older individuals carries a larger relative risk for these outcomes compared with younger individuals is unclear at this time. Other domains, such as health-related quality of life, may be mildly impacted on after an episode of AKI. No effective therapies for AKI currently are available for widespread use. However, because the incidence of AKI is highest in the elderly and the phenotype is not discernibly different from AKI in all populations, future randomized controlled trials of interventions for AKI should be performed in the elderly population.

Background: 2009 pandemic influenza A(H1N1) has led to a global increase in severe respiratory illness. Little is known about kidney outcomes and dialytic requirements in critically ill patients infected with pandemic H1N1.Study Design: Prospective observational study.Setting & Participants: 50 patients with pandemic H1N1 admitted to any of 7 intensive care units in Manitoba, Canada, were prospectively followed.Outcome & Measurements: Outcomes were kidney injury and kidney failure defined using RIFLE (risk, injury, failure, loss, end-stage disease) criteria or need for dialysis therapy.Results: The pandemic H1N1 group was composed of 50 critically ill patients with pandemic H1N1 with severe respiratory syndrome (47 confirmed cases, 3 probable). Kidney injury, kidney failure, and need for dialysis occurred in 66.7%, 66%, and 11% of patients, respectively. Mortality was 16%. Kidney failure was associated with increased death (OR, 11.29; 95% CI, 1.29-98.9), whereas the need for dialysis was associated with an increase in length of stay (RR, 2.38; 95% CI, 2.13-25.75).Limitations: Small population studied from single Canadian province; thus, limited generalizability.Conclusions: In critically ill patients with pandemic H1N1, kidney injury, kidney failure, and the need for dialysis are common and associated with an increase in mortality and length of intensive care unit stay.