Table 1.
Characteristics of the Study Participants
| Enrollment N=473,026 | Follow-Up N=19,518 | P for difference | |
|---|---|---|---|
| Age (mean (sd)) | 56.55 (8.09) | 57.17 (7.40) | <0.01 |
| Townsend Deprivation Index (mean (sd)) | −1.35 (3.07) | −2.05 (2.68) | <0.01 |
| Male | 216,154 (45.69%) | 9,521 (48.78%) | <0.01 |
| Race/Ethnicity | |||
| British or Irish White | 448, 320 (94.78)% | 19,096 (97.84%) | <0.01 |
| Education | |||
| College Graduate or Higher | 152,586 (32.26%) | 8,513 (43.62%) | <0.01 |
| Air Pollution in 2010 (mean, IQR) | |||
| NOX | 44.00 (16.35) | 43.22 (16.16) | <0.01 |
| NO2 | 26.63 (9.74) | 26.06 (8.85) | <0.01 |
| PM2.5 | 9.99 (1.28) | 9.97 (1.34) | 0.07 |
| PM2.5absorbance | 1.18 (0.30) | 1.17 (0.24) | <0.01 |
| PM2.5–10 | 6.43 (0.79) | 6.34 (0.60) | <0.01 |
| PM10 | 16.23 (1.76) | 15.94 (1.73) | <0.01 |
| Distance to Road, m (median, sd) | 378.79 (62.94) | 358.42 (70.75) | <0.01 |
| Traffic intensity, VPD (median, sd) | 17,053 (21,049) | 15,763 (21,961) | <0.01 |
| Anthropometric and body composition Measures at Enrollment | |||
| BMI (mean (sd)) | 27.42 (4.78) | 26.89 (4.52) | <0.01 |
| Waist-Hip-Ratio (mean (sd)) | 0.87 (0.09) | 0.86 (0.09) | <0.01 |
| Body Fat % (mean (sd)) | 31.41 (8.53) | 30.54 (8.44) | <0.01 |
| Obesity (BMI) (N %) | 115,041 (24.32%) | 3,929 (20.13%) | <0.01 |
| Abdominal Obesity (WHR) (N %) | 234,240 (49.52%) | 8,851 (45.35%) | <0.01 |
| Body Fat % Obesity (N %) | 262,778 (56.38%) | 10,073 (52.43%) | <0.01 |
| BMI Genetic Risk Score | 0.024 (0.002) | 0.024 (0.002) | <0.01 |
Enrollment numbers include complete cases with values for waist hip ratio, age, NO2 air pollution values, the BMI risk score, education, Townsend Deprivation Index, race/ethnicity, and assessment centre. A smaller number of these participants have available PM values (n=440,193 at enrollment, and 19,514 at follow-up); PM values were not reported for participants in some regions due to unreliability of the air pollution estimates. All air pollution estimates are annual averages from 2010. P for difference indicates the difference between those who returned for follow-up and those who did not return for follow-up (t-tests for continuous variables, chi-square tests for categorical). Traffic intensity in vpd is vehicles per day, and distance to road is meters.