Abstract
Background and Aims
Chronic hemodialysis (HD) is associated with prolonged immobilization, chronic inflammation, and protein-energy wasting, which can decrease muscle mass and impair their function. HD also contributes to excessive fatigue, decreased functional capacity and exercise tolerance, which influence HD patients’ everyday lives in multiple areas - personal and professional life as well as everyday activities.
The study aimed to analyze the relationship between HD patients’ body composition, muscle mass, strength and physical performance, and their reported quality of life (QoL).
Method
We enrolled adult, stable patients chronically HD for at least 3 months. Patients’ height and weight were measured; their overhydration (calculated as a percentage of dry weight) and body composition (lean tissue mass - LTM, fat tissue mass - FTM) were assessed using an electrical bioimpedance analyzer (BCM Fresenius™). Skeletal muscle mass (SMM) was calculated. The maximal voluntary force of five muscle groups of both lower extremities was assessed with a handheld dynamometer (microFET®2). Physical performance was evaluated with the Short Physical Performance Battery (SPPB), a tool assessing gait speed, chair stand, and balance. All measurements were performed by trained personnel before the same midweek dialysis session.
The Short Form-36 (SF-36), EQ-5D and EQ-VAS questionnaires were utilized in self-assessment of QoL and functional capacity. The SF-36 questionnaire consists of two primary components: physical health (PHC) and mental health (MHC). EQ-5D and EQ-VAS assess patients’ health status across five dimensions and their overall health perception.
Coexisting conditions were assessed using the Charlson Comorbidity Index (CCI). Laboratory data (red blood cell and iron metabolism parameters, calcium, phosphate, and PTH) from 3 routine monthly assessments preceding the study were collected from medical records.
Results
We enrolled 60 HD patients (20F, 40M) with a mean age of 61.9±13.5 years and median time of HD of 34.5 (10-81.8) months.
Mean LTM% was 48.3±13.2%, FTM% 35.6±9.9% and median overhydration was 0.8 (-0.4-2.7) %. Median SPPB score was 9 (6-11) points; 4 patients presented with severe, 12 with moderate and 44 with mild or no functional limitations. The mean score of CCI was 6.1±2.6 points.
The mean SF-36 QoL score was 59.5±17; the score was unrelated to sex (P=.649), age (P=.165) and HD vintage (P=.349). Median values of the PHC and MHC were 54.2 (41.1-69.1) and 67.9 (77.7-17.3), respectively. Both components correlated with each other (R=.67, p<.001). EQ-D5 [median of 1.6 (1.2-2.2) points] and EQ-VAS [median of 60 (50-80) %] scores significantly correlated with SF-36 QoL (R=-.75, P<.001 and R=.50, P<.001, respectively).
SF-36 QoL correlated positively with SMM (R=.36, P=.005), LTM% (R=.39, P=.002) and SPPB scores (R=.28, P=.030), but negatively with FTM% (R=-.36, P=.004). PHC correlated positively with lower extremity muscle strength (R from .29 to .44, every P<.05), SMM (R=.31, P=.017), LTM% (R=.34, P=.008) and SPPB scores (R=.38, P=.003), and inversely with FTM% (R=-.27, P=.030) and CCI scores (R=-.33, P=.009). MHC correlated with positively with SMM (R=.29; P=.024) and LTM% (R=.40, P=.002), but inversely with FTM% (R=.37; P=.003).
No significant correlations between laboratory results and other parameters were found.
Conclusion
Better physical performance, higher lean tissue percentage, higher muscle mass and strength, as well as lower fat percentage and lesser comorbidity burden are associated with better self-perceived quality of life in HD patients - both physical and mental health.
Subjective well-being in non-obese individuals depends strongly on body composition
