Neighborhood-Level Analysis on the Impact of Accessibility to Fast Food and Open Green Spaces on the Prevalence of Obesity

BACKGROUND

The complex epidemiology of obesity includes environmental factors. We examined how accessibility to fast food restaurants and green spaces is associated with obesity.

METHODS

We used geocoded body mass index values of 20,927 subjects that visited the largest statewide health care network in Rhode Island. Spatial analysis and logistic regression were used to examine the association of obesity at the individual level, and obesity hot and cold spots with the accessibility to fast food restaurants and green space areas.

RESULTS

The age-adjusted prevalence of obesity in our sample was 33%. Obese subjects were less likely to live in neighborhoods with the highest accessibility to green space areas (odds ratio [OR] 0.89; 95% confidence interval [CI], 0.81-0.97), compared with neighborhoods with low accessibility. Obese subjects were more likely to live in neighborhoods with medium or high accessibility to fast food restaurants (OR 1.22; 95% CI, 1.14-1.31; OR 1.20; 95% CI, 1.10-1.32, respectively). Looking at obesity clustering, hot spots were 18% and 21% less likely to be located in neighborhoods with medium and high accessibility to green space areas, respectively (OR 0.82; 95% CI, 0.76-0.88; OR 0.79; 95% CI, 0.71-0.86). In contrast, hot spots were 1.65 and 4.81 times more likely to be located in neighborhoods with medium and high accessibility to fast food restaurants, respectively (OR 1.65; 95% CI, 1.53-1.77; OR 4.81; 95% CI, 4.39-5.27, respectively).

CONCLUSIONS

Accessibility to fast food restaurants is positively associated with the presence of obesity hot spots, while access to green space areas is associated with decreased neighborhood obesity rates.

Peroxisome proliferator-activated receptors and biotransformation responses in relation to condition factor and contaminant burden in tilapia species from Ogun River, Nigeria

A major development in fishery science has been the Fulton's condition factor (CF) as a reliable physiological index of fish growth and health status (Fulton 1902). As a general rule, CF-value greater than 1 (>1) should be regarded as an indicator for good growth and health. Therefore, exposure of fish to contaminants in the environment will be expected to produce a reduction in scope for growth, since energy for growth will be allocated to overcome stressful conditions. In the present study, we hypothesized that tilapia species from Ogun River (Nigeria) are experiencing severe contaminant-induced obesogen effects leading to high CF (≥ 2) in fish with pathological alterations. The environmental obesogen hypothesis has related the interaction between environmental pollutants and PPAR isoform activation In this respect, peroxisome proliferator-activated receptors (PPARs) and biotransformation responses in relation to contaminant burden were investigated in a total of 1074 specimens of Tilapias species (Tilapia guineensis, Sarotherodon galileaus and Oreochromis niloticus) collected from three areas with different degrees of anthropogenic contamination and from a putative control site along the Ogun River. Liver mRNA expression of cytochrome cyp1 isoforms (cyp1a, 1b and 1c) and PPAR isoforms (ppar-α, β and γ) were analyzed using validated real-time PCR. Fish were also analyzed for CF and muscle contaminant burden (aliphatic and polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls). A significant increase in mRNA expression of cyp1- and ppar isoforms was observed in fish from polluted areas, and these results paralleled data on PCBs and PAHs tissue concentrations. Further, cyp1 isoforms showed clear sex-related differences, with higher mRNA expression in male fish than in females. Principal component analysis revealed a relationship between cyp1 isoforms, ppar-α, β, PCBs and PAHs and these interactions may suggest a crosstalk between AhR- and PPARs mediated pathways on metabolic and energetic processes. The PCA biplot also highlighted a positive relationship between ppar-γ, body weight, total length and PAHs. The CF for fish from all the sites was ≥ 2 indicating that this parameter may not be a reliable index for evaluating fish growth and health condition, especially in wild fish population exposed to complex cocktails of environmental pollutants.