Psychosocial Factors Influence Physical Activity after Dysvascular Amputation: A Convergent Mixed-Methods Study.

BACKGROUND: Physical function is a common target of rehabilitation intervention to improve disability and physical activity after dysvascular lower-limb amputation (LLA); yet, the influence of psychosocial factors on physical activity is unclear. OBJECTIVE: To identify psychosocial factors with potential to influence clinically relevant measures of physical activity, physical function, and disability in light of participants' narratives. DESIGN: Convergent mixed-methods. SETTING: General community. PARTICIPANTS: Twenty participants with dysvascular LLA were enrolled if their most recent LLA was at least 1 year prior, they were ambulating independently with a prosthesis, and were between 45 and 88 years old. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Quantitative data included physical activity (activPAL; steps/d), physical function (Timed Up-and-Go; TUG), and disability (World Health Organization Disability Assessment Schedule 2.0; WHODAS 2.0). Qualitative data were collected via semistructured interviews. RESULTS: Higher steps/d was moderately correlated with better TUG time (r = -.58, P < .01), but was not correlated with WHODAS 2.0 score (r = -0.18; P > .10). Qualitative analysis of interviews, using an inductive, team-based, phenomenological approach, identified four themes: (1) perceptions of their prosthesis, (2) fear during mobility, (3) influence of LLA on life activities, and (4) positive outlook within social interactions. Mixed-methods analysis used an iterative approach to interpret and describe how psychosocial factors influence physical activity in four exemplar cases. CONCLUSIONS: Physical activity in people with dysvascular LLA results from an interaction among perceptions of their prosthesis, fear during mobility, influence of LLA on life activities, and positive outlook within social interactions. The overlapping nature of these themes suggests that interventions targeting psychosocial factors may be associated with improved physical activity, physical function, and subsequent disability after dysvascular LLA.

Elevated plasma homocysteine and cysteine are associated with endothelial dysfunction across menopausal stages in healthy women.

Hyperhomocysteinemia is associated with endothelial dysfunction and increased cardiovascular disease (CVD). We determined whether elevated homocysteine (Hcy) and markers of Hcy metabolism were associated with the previously reported endothelial dysfunction across stages of the menopause transition. Brachial artery flow-mediated dilation (FMD) and plasma concentrations of Hcy, cysteine, and methionine were measured in healthy women (n = 128) 22-70 yr of age categorized as premenopausal (n = 35), perimenopausal (early: n = 16; late: n = 21), and postmenopausal (early: n = 21; late: n = 35). Dietary intake of micronutrients involved in Hcy metabolism (e.g., vitamins B6, B12, folate) was assessed in a subpopulation of women. Hcy and cysteine concentrations were progressively higher, and methionine was progressively lower across menopausal stages (all P < 0.005). The higher Hcy and cysteine concentrations correlated with lower circulating estradiol levels (r = -0.49 and -0.50, respectively, both P < 0.001). FMD was inversely correlated with Hcy (r = -0.25, P = 0.004) and cysteine (r = -0.39, P < 0.001) and positively correlated with methionine concentrations (r = 0.25, P = 0.005). Dietary intake of vitamins B6 and B12 (both P < 0.05) were lower in postmenopausal women. Vitamin B12 intake correlated with FMD (r = 0.22, P = 0.006). These data suggest that declines in estradiol across stages of the menopause transition may lead to elevations in Hcy and cysteine that may contribute to endothelial dysfunction in postmenopausal women. Future studies should examine whether targeting Hcy metabolism during the perimenopausal to early postmenopausal period with interventions, including diet, attenuates or reverses the decline in endothelial function in women. NEW & NOTEWORTHY Declines in circulating estradiol across the stages of the menopausal transition may lead to elevations in Hcy and cysteine concentrations that may contribute to endothelial dysfunction. Abnormalities in the Hcy metabolic pathways, possibly related to dietary deficiencies of vitamins B12 and B6 and folate, may contribute to elevations in Hcy and cysteine concentrations. Findings also suggest that higher cysteine levels may be more damaging to the vascular endothelium than Hcy.