Muscle Mass Assessed by Computed Tomography at the Third Lumbar Vertebra Predicts Patient Survival in Chronic Kidney Disease.

OBJECTIVE: Muscle mass is a key element for the evaluation of nutritional disturbances in patients with chronic kidney disease (CKD). Low muscle mass is associated with increased morbidity and mortality. The assessment of muscle mass by computed tomography at the third lumbar vertebra region (CTMM-L3) is an accurate method not subject to errors from fluctuation in the hydration status. Therefore, we aimed at investigating whether CTMM-L3 was able to predict mortality in nondialyzed CKD 3-5 patients. METHODS: This is a prospective observational cohort study. We evaluated 223 nondialyzed CKD patients (60.3 ± 10.6 years; 64% men; 50% diabetics; glomerular filtration rate 20.7 ± 9.6 mLmin1.73 m2). Muscle mass was measured by CTMM-L3 using the Slice-O-Matic software and analyzed according to percentile adjusted by gender. Nutritional parameters, laboratory data, and comorbidities were evaluated, and mortality was followed up for 4 years. RESULTS: During the study period, 63 patients died, and the main cause of death was cardiovascular disease. Patients who died were older, had lower hemoglobin and albumin, as well as lower muscle markers. CTMM-L3 below the 25th percentile was associated with higher mortality according to the Kaplan-Meier curve (P = .017) and in Cox regression analysis (crude hazard ratio, 1.87 [95% confidence interval, 1.11-3.16]), also when adjusting for potential confounders (hazard ratio 1.83 [95% confidence interval 1.02-3.30]). CONCLUSION: Low muscle mass measured by computed tomography at the third lumbar vertebra region is an independent predictor of increased mortality in nondialyzed CKD patients.

Association of Sarcopenia With Nutritional Parameters, Quality of Life, Hospitalization, and Mortality Rates of Elderly Patients on Hemodialysis.

OBJECTIVE: This study aimed to assess whether diminished muscle mass, diminished muscle strength, or both conditions (sarcopenia) are associated with worse nutritional status, poor quality of life (QoL), and hard outcomes, such as hospitalization and mortality, in elderly patients on maintenance hemodialysis (MHD). DESIGN AND SUBJECTS: This is a multicenter observational longitudinal study that included 170 patients on MHD (age 70 ± 7 years, 65% male) from 6 dialysis centers. MAIN OUTCOME MEASURE: The European Working Group on Sarcopenia in Older People defines sarcopenia as the presence of both low muscle mass by appendicular skeletal + low muscle function by handgrip strength. This study evaluated the clinical and nutritional status (laboratory, anthropometry, dual-energy X-ray absorptiometry, 7-point subjective global assessment) and QoL (Kidney Disease Quality of Life) at baseline. Hospitalization and mortality were recorded during 36 months. RESULTS: Reduced muscle mass was observed in 64% of the patients, reduced muscle strength in 52%, and sarcopenia in 37%. The group with sarcopenia was older, had a higher proportion of men and showed worse clinical and nutritional conditions when compared with patients without sarcopenia. Although reduced muscle mass was strongly associated with poor nutritional status, low muscle strength was associated with worse QoL domains. In the multivariate Cox analyses adjusted by age, gender, dialysis vintage, and diabetes mellitus, low muscle strength alone and sarcopenia were associated with higher hospitalization, and sarcopenia was a predictor of mortality. CONCLUSION: In conclusion, in this sample, comprised of elderly patients on MHD, sarcopenia was associated with worse nutritional and clinical conditions and was a predictor of hospitalization and mortality.

Muscle mass assessment by computed tomography in chronic kidney disease patients: agreement with surrogate methods.

BACKGROUND/OBJECTIVES: Patients with chronic kidney disease (CKD) are subjected to muscle wasting. Therefore, it is important to investigate surrogate methods that enable the assessment of muscle mass loss in the clinical setting. We aimed to analyze the agreement between computed tomography (CT) and surrogate methods for the assessment of muscle mass in non-dialysis CKD patients. SUBJECTS/METHODS: Cross-sectional study including 233 non-dialysis patients on CKD stages 3 to 5 (61 ± 11 years; 64% men; glomerular filtration rate 22 (14-33) mL/min/1.73 m2). The muscle mass was evaluated by CT and bioelectrical impedance, skinfold thicknesses, midarm muscle circumference (MAMC), the predictive equations of Janssen and Baumgartner and the physical examination of muscle atrophy from the subjective global assessment. RESULTS: In males, the MAMC showed the best agreement with CT as indicated by the kappa test (k = 0.57, P < 0.01), sensitivity (S = 68%), specificity (S = 89%) and accuracy (area under the curve-AUC = 0.78), followed by the Baumgartner equation (kappa = 0.46, P < 0.01; sensitivity = 60%; specificity = 87% and AUC = 0.73). In female, the Baumgartner equation showed the best agreement with CT (kappa = 0.43, P < 0.01; sensitivity = 57%; specificity = 86% and AUC = 0.71). CONCLUSIONS: The MAMC and Baumgartner equation showed the best agreement with CT for the assessment of muscle mass in non-dialysis CKD patients.