Table 1.
Distribution of Baseline Characteristics by Baseline Racial Residential Segregation and Racial Discrimination Categories
| Baseline Characteristics | Baseline Segregation Category1 | Experiences of Racial Discrimination2 | ||||
|---|---|---|---|---|---|---|
| High % | Medium % | Low % | None % | 1–2 % | 3+ % | |
| N | 1774 | 262 | 139 | 345 | 409 | 934 |
| Mean follow-up time (years) | 21.5 | 21.7 | 21.1 | 21.2 | 21.4 | 21.4 |
| N incident diabetes events | 364 | 55 | 23 | 74 | 93 | 200 |
| Percent developing incident diabetes | 20.5% | 21.0% | 16.6% | 21.5% | 18.7% | 21.4% |
| Age- Mean (SD) | 24.3 (3.9) | 24.9 (3.6) | 24.8 (3.3) | 24.2 (3.8) | 24.2 (3.8) | 24.6 (3.8) |
| Female gender | 57.7% | 55.7% | 54.0% | 66.4% | 58.4% | 53.0% |
| Field center: | ||||||
| Birmingham, AL | 26.1% | 26.7% | 10.1% | 30.5% | 28.5% | 21.0% |
| Chicago, IL | 20.3% | 14.5% | 40.3% | 24.9% | 20.8% | 19.4% |
| Minneapolis, MN | 22.9% | 20.6% | 15.1% | 15.4% | 18.7% | 26.9% |
| Oakland, CA | 30.7% | 38.2% | 34.5% | 29.2% | 32.0% | 32.7% |
| Parental history of diabetes | 17.4% | 13.0% | 18.0% | 16.0% | 18.0% | 16.5% |
| Married/married-like relationship | 28.1% | 29.4% | 33.8% | 26.9% | 25.8% | 31.1% |
| Educational attainment: | ||||||
| <High school | 14.2% | 8.0% | 8.6% | 17.6% | 11.6% | 12.3% |
| High school diploma | 38.2% | 33.2% | 29.5% | 41.6% | 40.6% | 33.1% |
| Some college or more | 47.6% | 58.8% | 61.9% | 40.8% | 47.8% | 54.6% |
| Current smoker | 34.3% | 24.0% | 27.9% | 33.2% | 30.2% | 34.0% |
| Alcohol use3 | ||||||
| None | 47.6% | 50.6% | 38.9% | 51.3% | 49.1% | 44.9% |
| Moderate | 22.5% | 20.7% | 30.9% | 22.3% | 23.8% | 22.3% |
| Heavy | 29.9% | 28.7% | 30.2% | 26.4% | 28.1% | 32.8% |
| Total physical activity score- Mean (SD)4 | 377.0 (305.5) | 421.6 (292.2) | 441.3 (312.3) | 339.9 (286.8) | 352.0 (270.5) | 425.9 (326.6) |
| Alternative healthy eating index score- Mean (SD)5 | 30.2 (11.0) | 31.7 (11.7) | 30.7 (11.1) | 29.0 (11.1) | 29.8 (11.0) | 31.4 (11.1) |
| Waist circumference (cm) - Mean (SD) | 78.4 (12.1) | 77.9 (11.7) | 77.4 (11.0) | 78.0 (12.7) | 78.4 (12.4) | 78.3 (11.4) |
| Census tract poverty6- Mean (SD) | 25.8 (12.6) | 17.1 (10.0) | 11.7 (10.0) | 25.5 (13.2) | 24.2 (12.9) | 23.0 (12.6) |
| Tract population density- Mean (SD) | 13410.1 (10707.0) | 11747.3 (8546.8) | 15635.3 (16731.6) | 13469.4 (10753.8) | 13144.9 (10518.4) | 13439.9 (11368.4) |
Racial residential segregation categorized into high, medium, and low use the value of the local Gi* statistic, which measures the deviation of the census tract’s racial composition from that of the larger metropolitan area. A Gi* statistic z-score <0 was categorized as low, 0 to 1.96 as medium, and >1.96 as high segregation.
Racial discrimination was assessed via survey. Participants reported whether they had experienced discrimination in any of 7 domains (e.g. school, getting a job, work, getting housing, getting medical care, on the street or in a public setting, from the police or in the courts). Discrimination was categorized as no experiences, 1–2 experiences, or 3+ experiences. Racial discrimination was first assessed in year 7, so this value is used for baseline discrimination. As such, baseline discrimination was missing for 398 participants.
Alcohol use was categorized as usually consuming: 0 drinks per week (none), 1–7 drinks per week for women or 1–14 drinks per week for men (moderate), or >7 drinks per week for women or >14 drinks per week for men (heavy).
Total physical activity was measured using the CARDIA physical activity questionnaire, which assessed the frequency of participation in the past 12 months in 13 moderate and vigorous intensity activities. A total physical activity score was calculated by multiplying the frequency of participation by intensity of the activity and summing across activities to create a continuous exercise unit score.
Dietary quality was assessed in years 0, 7 and 20 using a diet history questionnaire on dietary intake for the previous 28 days. Diet quality was quantified using the Alternative Healthy Eating Index, which includes vegetables, fruits, whole grains, nuts/legumes, red/processed meat, sugar-sweetened beverages/fruit juice, trans fat, long-chain fats, polyunsaturated fatty acids, sodium, and alcohol consumption.
Census tract poverty was the percent of the participant’s residential census tract population living below the federal poverty threshold (range 0–100), using U.S. Census data