HA is associated with lower functional pain severity, with minimal impact on functional test scores. We interpreted this finding to represent an increase in the quality of the movement and functional activity. The change in functional pain did not correspond to changes in SF-36 quality-of-life scores.

Altered mitochondrial quality and function in muscle may be involved in age-related physical function decline. The role played by the autophagy–lysosome system, a major component of mitochondrial quality control (MQC), is incompletely understood. This study was undertaken to obtain initial indications on the relationship between autophagy, mitophagy, and lysosomal markers in muscle and measures of physical performance and lower extremity tissue composition in young and older adults. Twenty-three participants were enrolled, nine young (mean age: 24.3 ± 4.3 years) and 14 older adults (mean age: 77.9 ± 6.3 years). Lower extremity tissue composition was quantified volumetrically by magnetic resonance imaging and a tissue composition index was calculated as the ratio between muscle and intermuscular adipose tissue volume. Physical performance in older participants was assessed via the Short Physical Performance Battery (SPPB). Protein levels of the autophagy marker p62, the mitophagy mediator BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), the lysosomal markers transcription factor EB, vacuolar-type ATPase, and lysosomal-associated membrane protein 1 were measured by Western immunoblotting in vastus lateralis muscle biopsies. Older adults had smaller muscle volume and lower tissue composition index than young participants. The protein content of p62 and BNIP3 was higher in older adults. A negative correlation was detected between p62 and BNIP3 and the tissue composition index. p62 and BNIP3 were also related to the performance on the 5-time sit-to-stand test of the SPPB. Our results suggest that an altered expression of markers of the autophagy/mitophagy–lysosomal system is related to deterioration of lower extremity tissue composition and muscle dysfunction. Additional studies are needed to clarify the role of defective MQC in human muscle aging and identify novel biological targets for drug development.

Peripheral Artery Disease (PAD) is a vascular disease that affects over 8 million Americans. PAD patients commonly have difficulty walking due to pain in the legs during physical exertion. Supervised walking therapy has been recommended to improve walking performance and attenuate disease progression; however, this therapy remains underutilized in PAD patients. Recently, there has been evidence to suggest that stretching accomplished via an ankle dorsiflexion splint may improve vascular health and walking performance in PAD; however, it is currently unknown how this protocol affects tissue oxygenation (StO 2 ). The purpose of this study was to determine the impact of 4 wks of ankle dorsiflexion stretching on measures of tissue oxygenation in patients with PAD. Thirteen PAD patients (67.7 ± 7.9 years) were randomized to a stretch (n = 9) or a non-stretch control (n = 4) group. Patients in the stretch were instructed to wear the splint for 30 min/day, 5 days/wk for 4 wks. A 5-min vascular occlusion test was administered before and after the intervention. Measures of StO 2 recovery were calculated following the vascular occlusion test and while completing a 6-minute walk test (6MWT). All measures of StO 2 were derived via Near-Infrared Spectroscopy. Repeated measures ANOVA was used to analyze data. There was a significant improvement in StO 2 recovery in the stretch group compared to the control (Stretch: 0.35 ± 0.25 %/sec vs 0.53 ± 0.29 %/sec; Control: 0.57 ± 0.43 %/sec vs 0.32 ± 0.19 %/sec; p = 0.002). During the 6MWT, patients completing the stretching protocol significantly improved oxygen extraction in the first minute of the test (-0.63 ± 0.05 StO 2 vs -0.73 ± 0.09 StO 2 ); however, this improvement was not significantly different compared to changes in the control group. These results indicate an improvement in microvascular reactivity and oxygen extraction following 4 wks of splint-based stretching. This stretching intervention holds potential therapeutic value for PAD patients and warrants further investigation.

2016-12-23T18:52:10

2016-12-24T18:18:19