The short-term effects of sedentary behaviour on cerebral hemodynamics and cognitive performance in older adults: a cross-over design on the potential impact of mental and/or physical activity.

BACKGROUND: Sedentary behaviour might be a potential risk factor for cognitive decline. However, the short-term effects of sedentary behaviour on (cerebro) vascular and cognitive performance in older people are unknown. METHODS: We used a cross-over design with 22 older adults (78 years, 9 females) to assess the short-term hemodynamic and cognitive effects of three hours uninterrupted sitting and explored if these effects can be counteracted with regular (every 30 min) two-minute walking breaks. In addition, we investigated if low versus high mental activity during the three hours of sitting modified these effects. Before and after each condition, alertness, executive functioning, and working memory were assessed with the Test of Attentional Performance battery. Additionally, cerebral blood flow velocity (Transcranial Doppler) and blood pressure (Finapres) were measured in rest, and during sit-to-stand and CO2 challenges to assess baroreflex sensitivity, cerebral autoregulation, and cerebral vasomotor reactivity. RESULTS: No short-term differences were observed in cognitive performance, cerebral blood flow velocity, baroreflex sensitivity, cerebral autoregulation, or cerebral vasomotor reactivity across time, or between conditions. Blood pressure and cerebrovascular resistance increased over time (8.6 mmHg (5.0;12.1), p < 0.001), and 0.23 in resistance (0.01;0.45), p = 0.04). However, these effects were not mitigated by mental activity or by short walking breaks to interrupt sitting. CONCLUSIONS: In older individuals, three hours of sitting did not influence cognitive performance or cerebral perfusion. However, the sitting period increased blood pressure and cerebrovascular resistance, which are known to negatively impact brain health in the long-term. Importantly, we found that these effects in older individuals cannot be mitigated by higher mental activity and/or regular walking breaks. TRIAL REGISTRATION: Clinical trial registration URL: https://www.toetsingonline.nl/. Unique identifier: NL64309.091.17. Date of registration: 06-02-2018

Is there a bidirectional association between sedentary behaviour and cognitive decline in older adults? Findings from the Irish Longitudinal Study on Ageing

Research on whether sedentary behaviour (SB) is related to cognitive decline in older individuals is conflicting, potentially caused by methodological differences in previous studies. To inform public health policies, we analysed both the forward and reverse association across four-years between subjective TV time and objectively-measured SB and four cognitive outcome measures in older adults. The Irish Longitudinal Study on Ageing (TILDA) quantified time spent watching TV using a questionnaire and objective physical activity patterns with a GENEActiv accelerometer. Mixed model analysis examined whether these two measures of SB related to changes in cognitive function (immediate and delayed recall, MMSE, and animal naming task) during a four-year follow-up period. Furthermore, the reverse association between changes in cognition over the preceding four years and SB was investigated. We included 1,276 participants (67 ± 9 years). Longitudinally, every hour of objective SB per day was associated with a -0.01 (95%CI = -0.03;-0.00) lower MMSE score per year. Reversely, a worse decline in immediate and delayed recall over the preceding waves was related to slightly more objective SB (B = -0.24 (95%CI = -0.41;-0.07)) and TV time (B = -0.25 (95%CI = -0.48;-0.03)) at the end of those four years. To conclude, in healthy older individuals, higher levels of objective SB are related to cognitive decline across a four-year follow-up, although the magnitude and clinical relevance are questionable. As preceding cognitive decline is associated with more SB across follow-up, this suggests that a bidirectional association is plausible

Sedentary behaviour and brain health in middle-aged and older adults: A systematic review

Sedentary behaviour may increase the risk of dementia. Studying physiological effects of sedentary behaviour on cerebral health may provide new insights into the nature of this association. Accordingly, we reviewed if and how acute and habitual sedentary behaviour relate to brain health factors in middle-aged and older adults (≥45 years). Four databases were searched. Twenty-nine studies were included, with mainly cross-sectional designs. Nine studies examined neurotrophic factors and six studied functional brain measures, with the majority of these studies finding no associations with sedentary behaviour. The results from studies on sedentary behaviour and cerebrovascular measures were inconclusive. There was a tentative association between habitual sedentary behaviour and structural white matter health. An explanatory pathway for this effect might relate to the immediate vascular effects of sitting, such as elevation of blood pressure. Nevertheless, due to the foremost cross-sectional nature of the available evidence, reverse causality could also be a possible explanation. More prospective studies are needed to understand the potential of sedentary behaviour as a target for brain health

Hemodynamic and structural brain measures in high and low sedentary older adults.

Due to its cardiovascular effects sedentary behaviour might impact cerebrovascular function in the long term, affecting cerebrovascular regulatory mechanisms and perfusion levels. Consequently this could underly potential structural brain abnormalities associated with cognitive decline. We therefore assessed the association between sedentary behaviour and brain measures of cerebrovascular perfusion and structural abnormalities in community-dwelling older adults. Using accelerometery (GENEActiv) data from The Irish Longitudinal Study on Ageing (TILDA) we categorised individuals by low- and high-sedentary behaviour (≤8 vs >8 hours/day). We examined prefrontal haemoglobin oxygenation levels using Near-Infrared Spectroscopy during rest and after an orthostatic challenge in 718 individuals (66 ± 8 years, 52% female). Global grey matter cerebral blood flow, total grey and white matter volume, total and subfield hippocampal volumes, cortical thickness, and white matter hyperintensities were measured using arterial spin labelling, T1, and FLAIR MRI in 86 individuals (72 ± 6 years, 55% female). While no differences in prefrontal or global cerebral hemodynamics were found between groups, high-sedentary individuals showed lower hippocampal volumes and increased white matter hyperintensities compared to their low-sedentary counterparts. Since these structural cerebral abnormalities are associated with cognitive decline and Alzheimer's disease, future work exploring the causal pathways underlying these differences is needed

Intermediate care at a community hospital as an alternative to prolonged general hospital care for elderly patients: a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Demographic changes together with an increasing demand among older people for hospital beds and other health services make allocation of resources to the most efficient care level a vital issue. The aim of this trial was to study the efficacy of intermediate care at a community hospital compared to standard prolonged care at a general hospital.</p> <p>Methods</p> <p>In a randomised controlled trial 142 patients aged 60 or more admitted to a general hospital due to acute illness or exacerbation of a chronic disease 72 (intervention group) were randomised to intermediate care at a community hospital and 70 (general hospital group) to further general hospital care.</p> <p>Results</p> <p>In the intervention group 14 patients (19.4%) were readmitted for the same disease compared to 25 patients (35.7%) in the general hospital group (p = 0.03). After 26 weeks 18 (25.0%) patients in the intervention group were independent of community care compared to seven (10.0%) in the general hospital group (p = 0.02). There were an insignificant reduction in the number of deaths and an insignificant increase in the number of days with inward care in the intervention group. The number of patients admitted to long-term nursing homes from the intervention group was insignificantly higher than from the general hospital group.</p> <p>Conclusion</p> <p>Intermediate care at a community hospital significantly decreased the number of readmissions for the same disease to general hospital, and a significantly higher number of patients were independent of community care after 26 weeks of follow-up, without any increase in mortality and number of days in institutions.</p

Hospital discharge planning and continuity of care for aged people in an Italian local health unit: does the care-home model reduce hospital readmission and mortality rates?

<p>Abstract</p> <p>Background</p> <p>Hospital discharge planning is aimed to decrease length of stay in hospitals as well as to ensure continuity of health care after being discharged. Hospitalized patients in Turin, Italy, who are in need of medical, social and rehabilitative care are proposed as candidates to either discharge planning relying on a care-home model (DPCH) for a period of about 30 days, or routine discharge care. The aim of this study was to evaluate whether a hospital DPCH that was compared with routine care, improved patients' outcomes in terms of reduced hospital readmission and mortality rates in patients aged 64 years and older.</p> <p>Methods</p> <p>In a retrospective observational cohort study a sample of 380 subjects aged 64 years and over was examined. Participants were discharged from the hospital S.Giovanni Bosco in Turin, Italy from March 1^st, 2005 to February 28^th, 2006. Of these subjects, 107 received routine discharge care while 273 patients were referred to care-home (among them, 99 received a long-term care intervention (LTCI) afterwards while 174 did not). Data was gathered from various administrative and electronic databases. Cox regression models were used to evaluate factors associated with mortality and hospital readmission.</p> <p>Results</p> <p>When socio-demographic factors, underlying disease and disability were taken into account, DPCH decreased mortality rates only if it was followed by a LTCI: compared to routine care, the Hazard Ratio (HR) of death was 0.36 (95% Confidence Interval (CI): 0.20 – 0.66) and 1.15 (95%CI: 0.77 – 1.74) for DPCH followed by LTCI and DPCH not followed by LTCI, respectively. On the other hand, readmission rates did not significantly differ among DPCH and routine care, irrespective of the implementation of a LTCI: HRs of hospital readmission were 1.01 (95%CI: 0.48 – 2.24) and 1.18 (95%CI: 0.71 – 1.96), respectively.</p> <p>Conclusion</p> <p>The use of DPCH after hospital discharge reduced mortality rates, but only when it was followed by a long-term health care plan, thus ensuring continuity of care for elderly participants.</p