The association between neighbourhood greenspace and type 2 diabetes in a large cross-sectional study

OBJECTIVE: To investigate the relationship between neighbourhood greenspace and type 2 diabetes. DESIGN: Cross-sectional. SETTING: 3 diabetes screening studies conducted in Leicestershire, UK in 2004-2011. The percentage of greenspace in the participant's home neighbourhood (3 km radius around home postcode) was obtained from a Land Cover Map. Demographic and biomedical variables were measured at screening. PARTICIPANTS: 10,476 individuals (6200 from general population; 4276 from high-risk population) aged 20-75 years (mean 59 years); 47% female; 21% non-white ethnicity. MAIN OUTCOME MEASURE: Screen-detected type 2 diabetes (WHO 2011 criteria). RESULTS: Increased neighbourhood greenspace was associated with significantly lower levels of screen-detected type 2 diabetes. The ORs (95% CI) for screen-detected type 2 diabetes were 0.97 (0.80 to 1.17), 0.78 (0.62 to 0.98) and 0.67 (0.49 to 0.93) for increasing quartiles of neighbourhood greenspace compared with the lowest quartile after adjusting for ethnicity, age, sex, area social deprivation score and urban/rural status (P[subscript: trend]=0.01). This association remained on further adjustment for body mass index, physical activity, fasting glucose, 2 h glucose and cholesterol (OR (95% CI) for highest vs lowest quartile: 0.53 (0.35 to 0.82); P[subscript: trend]=0.01). CONCLUSIONS: Neighbourhood greenspace was inversely associated with screen-detected type 2 diabetes, highlighting a potential area for targeted screening as well as a possible public health area for diabetes prevention. However, none of the risk factors that we considered appeared to explain this association, and thus further research is required to elicit underlying mechanisms. TRIAL REGISTRATION NUMBER: This study uses data from three studies (NCT00318032, NCT00677937, NCT00941954).