Residential neighbourhood greenspace is associated with reduced risk of incident diabetes in older people: a prospective cohort study

Abstract

BackgroundThree cross sectional studies suggest that neighbourhood greenspace may protect against incident diabetes. This study uses data from a longitudinal study with a large sample size to investigate the association between greenspace and the occurrence of incident diabetes over time.MethodsData was from the European Prospective Investigation of Cancer Norfolk, UK, cohort, recruitment 1993–2007 (N = 23,865). Neighbourhoods were defined as 800 m circular buffers around participants’ home locations, according to their home postcode (zip code). Greenspace exposure was defined as the percentage of the home neighbourhood that was woodland, grassland, arable land, mountain, heath and bog, according to the UK Land Cover Map. Cox proportional hazards regression examined the association between neighbourhood greenspace exposure and incident diabetes. The population attributable fraction assessed the proportion of diabetes cases attributable to exposure to least green neighbourhoods. Mediation analysis assessed if physical activity explained associations between greenspace and diabetes. Interaction analysis was used to test for the modifying effect of rurality and socio-economic status on the relationship between greenspace and diabetes. Models were adjusted for known and hypothesised confounders.ResultsThe mean age of participants was 59 years at baseline and 55.1% were female. The mean follow-up time was 11.3 years. Individuals living in the greenest neighbourhood quartile had a 19% lower relative hazard of developing diabetes (HR 0.81; 95% CI 0.67, 0.99; p = 0.035; linear trend p = 0.010). The hazard ratio remained similar (HR 0.81; 95% CI 0.65, 0.99; p = 0.042) after adjusting for age, sex, BMI, whether a parent had been diagnosed with diabetes and socio-economic status at the individual and neighbourhood level. A HR of 0.97 was attributed to the pathway through physical activity in a fully adjusted model, although this was non-significant (95% CI 0.88, 1.08; p = 0.603). The incidence of diabetes in the least green neighbourhoods (with 20% greenspace on average) would fall by 10.7% (95% CI −2.1%, 25.2%; p = 0.106) if they were as green as the average neighbourhood observed across the whole cohort (59% greenspace on average). There were no significant interactions between rurality or socio-economic status and level of greenspace.ConclusionsGreener home neighbourhoods may protect against risk of diabetes in older adults, although this study does not support a mediation role for physical activity. Causal mechanisms underlying the associations require further investigation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-016-3833-z) contains supplementary material, which is available to authorized users.

Caracterización de adultos sin riesgo, con riesgo y con diabetes en el noreste de México

“…La muestra reclutada se integró en su mayoría por mujeres, lo que coincide con otros autores (14,16,22) , CC aumentada en mujeres >80 cm y en hombres >94 cm. Se midió con cinta métrica flexible SECA 203.…”

“…La revisión de literatura pone en evidencia factores individuales como falta de ejercicio, SP/OB, HTA, antecentes familiares de DM22, bajo nivel educativo y económico (14) , ansiedad, depresión (15) , consumo de sustancias psicoactivas (16) , baja percepción de riesgo (17) ; así como factores en diferentes niveles de estructura social como el escaso apoyo social (18) , extensas jornadas de trabajo, estrés laboral (19,20) , inseguridad alimentaria, percepción de problemas comunitarios (21,22) , desarrollo urbano y urbanización (23)(24)(25) el bajo nivel educativo en la comunidad (26) , bajo acceso a la atención en el sistema sanitario (27,28) y la economía local y nacional (29,30) .…”

Residential neighbourhood greenspace is associated with reduced risk of cardiovascular disease: A prospective cohort study

“…Information on the study design and setting, exposure to neighbourhood greenspace, physical activity and some of the covariates and confounders has been published previously, as a similar approach to the methods and analyses was used for this study [36]. This study advances previous work by examining a different health outcome, which is an important public health concern linked to modifiable lifestyle behaviours.…”

“…Methods used previously [36] were used to define the exposure variable; greenspace coverage (percentage) in the home neighbourhood of the participant. Briefly, the home postcode (zip [40].…”

Novel green space measures and birthweight in Queensland, Australia

“…A small number of studies have found a reduced risk of type 2 diabetes with higher levels of green space. [156][157][158] A recent meta-analysis of six studies found an overall reduction in risk of diabetes for increasing levels of green space in the pooled analysis. 159 An increased odds of developing diabetes has been seen for areas with lower green space, even when BMI was not related to green space.…”