Muscle strength, mobility, quality of life and falls in patients on maintenance haemodialysis: A prospective study

Abstract

The aim is to explore (i) the relationship between quality of life and physical parameters (muscle strength and mobility) among people undergoing maintenance haemodialysis; (ii) changes in strength and mobility over time and predictors of changes; and (iii) whether strength and mobility were associated with falls. We recruited 51 maintenance haemodialysis patients to a prospective longitudinal study. Baseline quality of life was assessed using the SF-36 physical component summary and mental component summary scores. Muscle strength (ankle dorsiflexion strength measured with a hand-held dynamometer), mobility (short physical performance battery) and falls history were assessed at baseline, 12 and 36 months. Associations between variables at baseline were assessed with linear regression models. Changes in physical parameters were evaluated with paired t-tests and prediction of falls assessed by negative binominal regression. Fifty and 34 patients completed 12 and 36 month follow-ups, respectively. Baseline mobility but not muscle strength correlated with physical component summary (P = 0.01 and P = 0.23, respectively). Neither baseline mobility nor muscle strength correlated with mental component summary. At 12 months, muscle strength and mobility had significantly deteriorated (mean ankle dorsiflexion strength 11.0 lb (SD 1.5) from 14.0 lb (SD 2.2), P < 0.01; short physical performance battery 8.5 (SD 2.8) from 9.3 (SD 2.6), P < 0.01). Falls at 12 and 36 months were predicted by baseline mobility (P = 0.06 and P = 0.02, respectively) but not muscle strength. Physical parameters appear to be associated with meaningful patient outcomes and showed measurable deterioration over relatively short time frames. Interventions, with the potential to slow physical decline in people receiving maintenance dialysis, such as exercise programmes, warrant further investigation.