Intramuscular and abdominal fat measured by computed tomography and mortality of hemodialysis patients.

BACKGROUND: In hemodialysis patients, high body mass index is associated with low mortality while abdominal obesity relates to increased mortality. We aimed to investigate the association between muscle mass, intramuscular fat and abdominal fat measured by abdominal computed tomography (CT), and mortality in this patients population. METHODS: This two-center retrospective cohort study included hemodialysis patients who underwent abdominal CT between January 2013 and December 2018. Skeletal muscle mass index (SMI), muscle radiation attenuation (MRA) as an index of intramuscular fat, and visceral fat to subcutaneous fat ratio (VSR) were calculated using CT images at the third lumbar vertebral level. Multivariate Cox proportional hazards model was used to determine the independent predictors of all-cause, cardiovascular and non-cardiovascular mortalities. RESULTS: The study included 344 patients (median age 71.0 years; female 33.7%), among whom 145 died during a median follow-up of 4.9 years-46 and 99 from cardiovascular and non-cardiovascular causes, respectively. Lower MRA [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.58-0.87, P = .001] and higher VSR (HR 1.17, 95% CI 1.01-1.37, P = .04) were independently associated with higher all-cause mortality but not with lower SMI (HR 0.87, 95% CI 0.68-1.11, P = .26). Lower MRA (HR 0.51, 95% CI 0.35-0.73, P < .001) and higher VSR (HR 1.29, 95% CI 1.09-1.54, P = .003) were also associated with cardiovascular and non-cardiovascular mortality, respectively. CONCLUSIONS: Intramuscular fat and abdominal fat as measured using abdominal CT in hemodialysis patients are stronger independent predictors of mortality than muscle mass.

Association of Postexercise Vagal Dysfunction With Protein-Energy Wasting and Noncardiovascular Outcomes in Patients Receiving Hemodialysis: A Retrospective Cohort Study.

OBJECTIVE: Postexercise vagal dysfunction is linked to noncardiovascular mortality in hemodialysis patients, but the mechanism is unknown. This study aimed to determine the association of cardiovagal neuropathy with systemic inflammation, protein-energy wasting, and noncardiovascular hospitalization. METHODS: This 2-center retrospective cohort study analyzed data from 280 hemodialysis patients who underwent exercise test. Patients were assessed for heart rate (HR) recovery (bpm) for 1 minute after exercise, a marker of vagal function, and were divided into 3 categories (Low: ≤ 6, Mid: 7-11, High: ≥ 12 bpm). We followed 1-year changes in the systemic inflammation-based prognostic score (Glasgow Prognostic Score [GPS]), body weight, and creatinine generation rate (CGR), an indicator of muscle mass, as well as 2-year hospitalization. RESULTS: The HR recovery category was associated with serum C-reactive protein and albumin levels and GPS. After 1 year, the low HR recovery category was associated with worsening in GPS (low, 0 [0-0.5]; mid, 0 [0-1]; high, 0 [0-0]), weight (low, 100.0 [96.1-102.5]; mid, 101.3 [98.9-105.0]; high, 100.5 [98.2-102.9]%), and CGR (low, 97.0 [88.5-111.4]; mid, 110.2 [90.9-124.8]; high, 106.2 [95.5-115.5]%), and the correlations with GPS and CGR remained consistent after adjusting for confounders such as exercise capacity and hospitalization during the follow-up period. There were 117 patients hospitalized. Compared to the high HR recovery category, the mid (hazard ratio: 1.8, 95% confidence interval [CI]: 1.1-3.1, P = .02) and low (hazard ratio: 2.4, 95% CI: 1.5-4.0, P = .001) categories were independently associated with an increased risk of all-cause hospitalization. For noncardiovascular disease hospitalization, the low HR recovery category was independently associated with increased risk of hospitalization (hazard ratio: 2.1, 95% CI: 1.2-3.7, P = .007). CONCLUSIONS: Vagal neuropathy in this population can contribute to adverse outcomes associated with systemic inflammation and protein-energy wasting.

Relationships between frailty and exercise capacity in patients undergoing hemodialysis: A cross-sectional study.

AIM: Hemodialysis (HD) patients have a high prevalence of frailty. The association between frailty and exercise capacity in HD patients has not been established. This study aimed to clarify the relationships between frailty and exercise capacity in HD patients. METHODS: This two-center cross-sectional study included HD patients who performed cardiopulmonary exercise testing. Participants were divided by frailty phenotype into robust, pre-frail, and frail using the revised Japanese version of the Cardiovascular Health Study criteria. Peak oxygen uptake (peakVO2 ) measured by cardiopulmonary exercise testing was compared with each frailty phenotype. The association between peakVO2 and frailty phenotype was analyzed using multivariate linear regression analysis adjusted for age, sex, body mass index diabetes mellitus, cardiovascular disease, cancer, history of fracture, hemoglobin, left ventricle ejection fraction, and percentage of heart rate reserve. RESULTS: The study included 136 patients (median age, 71.0 years; female, 23.5%), with 15.4%, 44.9%, and 39.7% with frailty phenotypes robust, pre-frail, and frail, respectively. PeakVO2 decreased with deterioration of the frailty phenotype (robust, median 15.1 [13.7-18.3] mL/min/kg; pre-frail, median 12.2 [10.5-14.4] mL/min/kg; frail, median 10.6 [9.2-12.5] mL/min/kg, P < 0.05). PeakVO2 decline was significantly associated with frail (B = -2.19, P = 0.004). Modeling individual frailty components showed a significant association between peakVO2 , usual gait speed (B = 2.38, P = 0.04), and low physical activity (B = -1.44, P = 0.004). CONCLUSION: Frailty in HD patients was associated with a decline in exercise capacity. HD patients with frailty need to improve exercise capacity, gait speed, and physical activity. Geriatr Gerontol Int 2023; 23: 795-802.