Sian Hill

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 participants 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 (Ptrend=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); Ptrend=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).

Is the number of fast-food outlets in the neighbourhood related to screen-detected type 2 diabetes mellitus and associated risk factors?

OBJECTIVE We investigated whether a higher number of fast-food outlets in an individuals home neighbourhood is associated with increased prevalence of type 2 diabetes mellitus and related risk factors, including obesity. DESIGN Cross-sectional study. SETTING Three UK-based diabetes screening studies (one general population, two high-risk populations) conducted between 2004 and 2011. The primary outcome was screen-detected type 2 diabetes. Secondary outcomes were risk factors for type 2 diabetes. SUBJECTS In total 10 461 participants (mean age 59 years; 53% male; 21% non-White ethnicity). RESULTS There was a higher number of neighbourhood (500 m radius from home postcode) fast-food outlets among non-White ethnic groups (P<0.001) and in socially deprived areas (P<0.001). After adjustment (social deprivation, urban/rural, ethnicity, age, sex), more fast-food outlets was associated with significantly increased odds for diabetes (OR=1.02; 95% CI 1.00, 1.04) and obesity (OR=1.02; 95% CI 1.00, 1.03). This suggests that for every additional two outlets per neighbourhood, we would expect one additional diabetes case, assuming a causal relationship between the fast-food outlets and diabetes. CONCLUSIONS These results suggest that increased exposure to fast-food outlets is associated with increased risk of type 2 diabetes and obesity, which has implications for diabetes prevention at a public health level and for those granting planning permission to new fast-food outlets.

Mapping X-ray absorption fine structure in the quantum efficiency of an X-ray charge-coupled device

Recent measurements have shown that high-resolution silicon detectors are beginning to resolve x-ray absorption fine structure (XAFS) produced in the detectors themselves. Unless calibrated, such structure threatens to ‘pollute’ spectroscopic measurements. An experiment has begun map this structure to systematically in an x-ray charge-coupled device (CCD) over the energy range 300–2100 eV. The program is novel in that the synchrotron radiation source has to be operated with a ring current reduced by five orders of magnitude so that individual photons can be recorded by the CCD. Results of the detailed spectroscopic response around the nitrogen, oxygen and silicon K edges are presented. The measured quantum efficiency shows considerable near-edge structure which is modified by the presence of the various insulation layers used in MOS construction, reflecting the chemical rather than elemental nature of the interaction environment. It is pointed out that the measurement of XAFS in x-ray CCDs is potentially a powerful diagnostic tool with which to explore surface structures.

The association between air pollution and type 2 diabetes in a large cross-sectional study in Leicester: The CHAMPIONS Study

BACKGROUND Observational evidence suggests there is an association between air pollution and type 2 diabetes; however, there is high risk of bias. OBJECTIVE To investigate the association between air pollution and type 2 diabetes, while reducing bias due to exposure assessment, outcome assessment, and confounder assessment. METHODS Data were collected from 10,443 participants in three diabetes screening studies in Leicestershire, UK. Exposure assessment included standard, prevailing estimates of outdoor nitrogen dioxide and particulate matter concentrations in a 1×1km area at the participants home postcode. Three-year exposure was investigated in the primary analysis and one-year exposure in a sensitivity analysis. Outcome assessment included the oral glucose tolerance test for type 2 diabetes. Confounder assessment included demographic factors (age, sex, ethnicity, smoking, area social deprivation, urban or rural location), lifestyle factors (body mass index and physical activity), and neighbourhood green space. RESULTS Nitrogen dioxide and particulate matter concentrations were associated with type 2 diabetes in unadjusted models. There was no statistically significant association between nitrogen dioxide concentration and type 2 diabetes after adjustment for demographic factors (odds: 1.08; 95% CI: 0.91, 1.29). The odds of type 2 diabetes was 1.10 (95% CI: 0.92, 1.32) after further adjustment for lifestyle factors and 0.91 (95% CI: 0.72, 1.16) after yet further adjustment for neighbourhood green space. The associations between particulate matter concentrations and type 2 diabetes were also explained away by demographic factors. There was no evidence of exposure definition bias. CONCLUSIONS Demographic factors seemed to explain the association between air pollution and type 2 diabetes in this cross-sectional study. High-quality longitudinal studies are needed to improve our understanding of the association.