Table 2.
Characteristics of participants in the REGARDS cohort random sample by oxidative balance score (OBS) interval (higher intervals represent higher antioxidant exposure) (n = 682)
| Characteristica | All | OBS |
||||
|---|---|---|---|---|---|---|
| interval 1 0–5 |
interval 2 6–9 |
interval 3 10–13 |
interval 4 14–17 |
interval 5 18–22 |
||
| n | 682 | 22 | 161 | 272 | 195 | 32 |
| Age, years | 66.9 (11.9) | 61.3 (10.6) | 65.9 (12.6) | 67.0 (12.1) | 68.7 (11.0) | 64.0 (11.3)b |
| Female, % | 51.3 | 54.6 | 49.7 | 51.1 | 50.8 | 62.5 |
| White, % | 56.3 | 40.9 | 59.0 | 55.5 | 54.4 | 71.9 |
| Current smoking, % Physically inactive | 13.9 | 31.8 | 20.5 | 13.2 | 6.1 | 21.9b |
| ≤3 times/week, % | 71.7 | 81.8 | 78.0 | 70.3 | 66.8 | 75.0 |
| Income < USD 20k, % | 15.3 | 13.6 | 13.7 | 16.9 | 13.9 | 18.8 |
| Education < high school, % | 12.5 | 13.6 | 11.8 | 14.3 | 10.8 | 9.4 |
| Hypertension, % | 56.9 | 77.3 | 50.3 | 59.4 | 57.3 | 53.1 |
| Diabetes, % | 19.7 | 18.2 | 16.9 | 21.0 | 22.2 | 9.4 |
| Waist circumference, cm | 94.7 (15.0) | 96.9 (12.3) | 94.6 (15.3) | 95.9 (15.3) | 94.0 (15.1) | 88.7 (9.7) |
| BMI | 28.7 (5.9) | 30.3 (3.8) | 28.1 (5.9) | 29.3 (6.3) | 28.5 (5.5) | 27.6 (5.1) |
| Calories, kcal | 1,766 (761) | 2,052 (826) | 1,929 (795) | 1,719 (797) | 1,634 (631) | 1,960 (760)b |
| eGFR, mL/min/1.73m2 | 87 (70–99) | 90 (67–110) | 88 (69–100) | 86 (69–98) | 86 (72–97) | 92 (72–104) |
| ACR, mg/g | 7.3 (4.5–14.6) | 5.0 (3.3–11.5) | 7.0 (4.1–12.7) | 7.2 (4.9–14.0) | 7.7 (4.4–18.4) | 9.3 (4.4–23.7) |
| CKDc, % | 22.4 | 18.2 | 19.3 | 23.9 | 24.6 | 15.6 |
| IL-6, pg/mL | 2.8 (2.0–4.3) | 3.2 (2.3–4.4) | 2.9 (2.1–4.6) | 2.9 (2.0–4.3) | 2.8 (1.9–4.1) | 2.5 (1.8–3.9) |
| IL-8, pg/mL | 2.5 (1.8–3.5) | 2.4 (2.1–3.0) | 2.4 (1.7–3.8) | 2.5 (1.7–3.7) | 2.6 (1.9–3.3) | 2.2 (1.7–3.3) |
| IL-10, pg/mL | 9.3 (6.4–13.4) | 9.1 (5.4–14.5) | 9.3 (6.6–13.3) | 9.4 (6.4–13.8) | 9.4 (6.5–12.8) | 7.8 (6.4–12.6) |
| Fibrinogen, mg/dL | 388 (337–455) | 370 (333–451) | 393 (340–473) | 391 (339–447) | 382 (335–443) | 383 (325–482) |
| CRP, mg/L | 2.0 (0.9–4.9) | 3.2 (1.7–11.8) | 2.2 (0.9–5.1) | 2.1 (0.9–5.2) | 1.8 (0.8–4.4) | 1.8 (0.7–5.7) |
| WBC count, 1,000/µL | 5.5 (4.6–6.7) | 6.2 (5.1–7.9) | 5.6 (4.8–6.7) | 5.6 (4.5–6.6) | 5.5 (4.6–6.8) | 5.6 (4.8–6.1) |
| Cys C, mg/L | 1.0 (0.8–1.1) | 0.9 (0.8–1.1) | 1.0 (0.8–1.1) | 1.0 (0.8–1.2) | 1.0 (0.8–1.2) | 0.9 (0.8–1.1) |
OBS, oxidative balance score; BMI, body mass index; eGFR, estimated glomerular filtration rate; ACR, albumin/creatinine ratio; CKD, chronic kidney disease; IL, interleukin; CRP, C-reactive protein; WBC, white blood cell; Cys C, cystatin C.
Values for age, waist circumference, BMI, and calories are reported as mean (±SD). Values for eGFR, ACR, IL-6, IL-8, IL-10, fibrinogen, CRP, WBC count, and Cys C are reported as median (IQR). Sex, race, current smoking status, income, education, hypertension, diabetes, and chronic kidney disease (CKD) are reported as percent.
p < 0.05 based on the ANOVA, Kruskal-Wallis, or χ2 tests, as appropriate.
CKD was defined as eGFR <60 mL/min/1.73m2 or albuminuria ≥30 mg/g.