Short-term strength and balance training does not improve quality of life but improves functional status in individuals with diabetic peripheral neuropathy: a randomised controlled trial

Abstract

Aims/hypothesis: The aim of this study was to test the effectiveness of a structured strength and balance training intervention in improving health-related quality of life (HRQoL) and functional status in individuals with diabetic peripheral neuropathy (DPN). Methods: The study was a single-blind parallel-group randomised controlled trial comparing 2 months of once-weekly home-based strength and balance training against standard medical therapy. Participants were patients with physician-diagnosed type 2 diabetes and neuropathy recruited from five public sector institutions in Singapore between July 2014 and October 2017. Participants were block-randomised to intervention or control arms. Outcomes were assessed at baseline, 2 months and 6 months by a trained assessor blinded to group assignment. Primary outcomes were change in physical component summary (PCS) score of SF-36v2 (a 36-item generic HRQoL instrument that has been validated for use in Singapore) and EQ-5D-5L index score (derived from a five-item generic HRQoL instrument [EQ-5D-5L]) over 6 months. Secondary outcomes were change in functional status (timed up-and-go [TUG], five times sit-to-stand [FTSTS], functional reach, static balance, ankle muscle strength and knee range of motion) and balance confidence over 6 months. Mean differences in scores between groups were compared using mixed models. Results: Of the 143 participants randomised (intervention, n = 70; control, n = 73), 67 participants were included in each arm for the final intention-to-treat analysis. The two groups were similar, except in terms of sex. There were no significant differences between groups on the primary outcomes of PCS score (mean difference [MD] 1.56 [95% CI −1.75, 4.87]; p = 0.355) and EQ-5D-5L index score (MD 0.02 [95% CI −0.01, 0.06]; p = 0.175). There were significant improvements in TUG test performance (MD −1.14 [95% CI −2.18, −0.1] s; p = 0.032), FTSTS test performance (MD −1.31 [95% CI −2.12, −0.51] s; p = 0.001), ankle muscle strength (MD 4.18 [95% CI 0.4, 7.92] N; p = 0.031), knee range of motion (MD 6.82 [95% CI 2.87, 10.78]°; p = 0.001) and balance confidence score (MD 6.17 [95% CI 1.89, 10.44]; p = 0.005). No adverse events due to study participation or study intervention were reported. Conclusions/interpretation: Short-term structured strength and balance training did not influence HRQoL but produced sustained improvements in functional status and balance confidence at 6 months. More intensive interventions may be needed to influence HRQoL in these individuals. However, this intervention may be a useful treatment option for individuals with DPN to reduce the risk of falls and injuries. Trial registration: ClinicalTrials.gov NCT02115932 Funding: This work was supported by the National Medical Research Council, Singapore.