BackgroundIdentifying attributes of the built environment associated with health-enhancing levels of physical activity (PA) in older adults (≥65 years old) has the potential to inform interventions supporting healthy and active ageing. The aim of this study was to first systematically review and quantify findings on built environmental correlates of older adults’ PA, and second, investigate differences by type of PA and environmental attribute measurement.MethodsOne hundred articles from peer-reviewed and grey literature examining built environmental attributes related to total PA met inclusion criteria and relevant information was extracted. Findings were meta-analysed and weighted by article quality and sample size and then stratified by PA and environmental measurement method. Associations (p < .05) were found in relation to 26 individual built environmental attributes across six categories (walkability, residential density/urbanisation, street connectivity, access to/availability of destinations and services, infrastructure and streetscape, and safety) and total PA and walking specifically. Reported individual- and environmental-level moderators were also examined.ResultsPositive environmental correlates of PA, ranked by strength of evidence, were: walkability (p < .001), safety from crime (p < .001), overall access to destinations and services (p < .001), recreational facilities (p < .001), parks/public open space (p = .002) and shops/commercial destinations (p = .006), greenery and aesthetically pleasing scenery (p = .004), walk-friendly infrastructure (p = .009), and access to public transport (p = .016). There were 26 individual differences in the number of significant associations when the type of PA and environmental measurement method was considered. No consistent moderating effects on the association between built environmental attributes and PA were found.ConclusionsSafe, walkable, and aesthetically pleasing neighbourhoods, with access to overall and specific destinations and services positively influenced older adults’ PA participation. However, when considering the environmental attributes that were sufficiently studied (i.e., in ≥5 separate findings), the strength of evidence of associations of specific categories of environment attributes with PA differed across PA and environmental measurement types. Future research should be mindful of these differences in findings and identify the underlying mechanisms. Higher quality research is also needed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-017-0558-z) contains supplementary material, which is available to authorized users.

BackgroundPerceived and objectively-assessed aspects of the neighbourhood physical environment have been postulated to be key contributors to regular engagement in active travel (AT) in older adults. We systematically reviewed the literature on neighbourhood physical environmental correlates of AT in older adults and applied a novel meta-analytic approach to statistically quantify the strength of evidence for environment-AT associations.MethodsForty two quantitative studies that estimated associations of aspects of the neighbourhood built environment with AT in older adults (aged ≥ 65 years) and met selection criteria were reviewed and meta-analysed. Findings were analysed according to five AT outcomes (total walking for transport, within-neighbourhood walking for transport, combined walking and cycling for transport, cycling for transport, and all AT outcomes combined) and seven categories of the neighbourhood physical environment (residential density/urbanisation, walkability, street connectivity, access to/availability of services/destinations, pedestrian and cycling infrastructure, aesthetics and cleanliness/order, and safety and traffic).ResultsMost studies examined correlates of total walking for transport. A sufficient amount of evidence of positive associations with total walking for transport was found for residential density/urbanisation, walkability, street connectivity, overall access to destinations/services, land use mix, pedestrian-friendly features and access to several types of destinations. Littering/vandalism/decay was negatively related to total walking for transport. Limited evidence was available on correlates of cycling and combined walking and cycling for transport, while sufficient evidence emerged for a positive association of within-neighbourhood walking with pedestrian-friendly features and availability of benches/sitting facilities. Correlates of all AT combined mirrored those of walking for transport. Positive associations were also observed with food outlets, business/institutional/industrial destinations, availability of street lights, easy access to building entrance and human and motorised traffic volume. Several but inconsistent individual- and environmental-level moderators of associations were identified.ConclusionsResults support strong links between the neighbourhood physical environment and older adults’ AT. Future research should focus on the identification of types and mixes of destinations that support AT in older adults and how these interact with individual characteristics and other environmental factors. Future research should also aim to clarify dose-response relationships through multi-country investigations and data-pooling from diverse geographical regions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-017-0471-5) contains supplementary material, which is available to authorized users.

PROSPERO 2016:CRD42016051180.

No abstract

Herein, we review the applicability to human beta-cells of an electrophysiologically based hypothesis of the coupling of glucose metabolism to insulin secretion. According to this hypothesis, glucose metabolism leads to the generation of intracellular intermediates (including ATP), which leads to closure of ATP-sensitive K+ channels. Channel closure results in membrane depolarization, the onset of electrical activity, and voltage-dependent Ca2+ entry. The resultant rise in cytosolic Ca2+ leads to Ca(2+)-dependent exocytosis of insulin granules. We found that most of the published experimental evidence for human beta-cells supports this hypothesis. In addition, we present three other emerging lines of evidence in support of this hypothesis for human islet beta-cells: 1) the effects of pHi-altering maneuvers on insulin secretion and electrical activity; 2) preliminary identification of LVA and HVA single Ca2+ channel currents; and 3) validation of the feasibility of Cm measurements to track insulin granule exocytosis. On the basis of this last new line of evidence, we suggest that combinations of Cm measurements and electrical activity/membrane current measurements may help define the roles of diverse electrical activity patterns, displayed by human beta-cells, in stimulus-induced insulin secretion.