Table 2.
Baseline characteristics of metabolic syndrome analytic sample by IL-6 quartile, weighted to reflect study design
| Characteristic | All or n missing* | IL-6 quartile, pg/mL | |||
|---|---|---|---|---|---|
| Q1 (0.03 to <0.50) | Q2 (0.50 to <0.72) | Q3 (0.72 to <1.08) | Q4 (1.08 to 378) | ||
| n | 1,871 | 455 | 455 | 468 | 493 |
| Weighted n | 6,037 | 1,513 | 1,508 | 1,507 | 1,509 |
| Demographics | |||||
| Age, years | 0 | 60.4 (7.8) | 62.4 (8.2) | 64.0 (8.5) | 63.3 (8.3) |
| Black race | 0 | 36 | 39 | 46 | 57 |
| Female sex | 0 | 46 | 49 | 49 | 52 |
| Geographic region | 0 | ||||
| Stroke belt | 34 | 31 | 33 | 33 | |
| Stroke buckle | 21 | 24 | 21 | 24 | |
| Rest of U.S. | 45 | 46 | 46 | 43 | |
| Socioeconomic factors | |||||
| Education | 0 | ||||
| Less than high school | 4.6 | 5.1 | 6.4 | 8.9 | |
| High school | 20 | 24 | 22 | 26 | |
| Some college | 25 | 23 | 25 | 28 | |
| College graduate | 50 | 48 | 47 | 38 | |
| Household Income, $ | 0 | ||||
| <20,000 | 8.6 | 5.3 | 12 | 14 | |
| 20,000–35,000 | 16 | 20 | 23 | 25 | |
| 35,000–75,000 | 36 | 36 | 34 | 35 | |
| ≥75,000 | 28 | 28 | 22 | 16 | |
| Unwilling to report | 12 | 10 | 9.4 | 10 | |
| Disease | |||||
| Diabetes | 0 | 5.3 | 5.9 | 7.9 | 6.1 |
| Medication use | |||||
| Antihypertensive† | 18 | 25 | 32 | 40 | 42 |
| Fibrate | 0 | 0.7 | 0.0 | 0.4 | 0.0 |
| Niacin | 0 | 0.4 | 0.4 | 0.0 | 0.2 |
| Omega-3 fatty acid | 0 | 6.8 | 3.7 | 2.8 | 3.2 |
| Physical measures | |||||
| Waist circumference, cm | 0 | 86.3 (11.8) | 89.0 (11.8) | 92.3 (16.6) | 93.9 (14.9) |
| BMI, kg/m2 | 5 | 25.8 (3.9) | 26.7 (4.0) | 27.8 (4.6) | 28.5 (5.7) |
| Systolic blood pressure, mmHg† | 1 | 121 (14) | 122 (15) | 124 (15) | 125 (15) |
| Diastolic blood pressure, mmHg† | 1 | 75 (9) | 76 (8) | 76 (9) | 76 (9) |
| Laboratory measures | |||||
| Triglycerides, mmol/L | 0 | 1.1 (0.5) | 1.2 (0.5) | 1.2 (0.5) | 1.3 (1.4) |
| HDL, mmol/L | 0 | 1.5 (0.4) | 1.5 (0.4) | 1.4 (0.4) | 1.4 (0.4) |
| Glucose, mmol/L | 0 | 5.1 (0.7) | 5.2 (0.8) | 5.2 (1.2) | 5.1 (1.2) |
| Insulin, pmol/L | 111 | 44.7 (32.4, 64.5) | 51.6 (34.8, 75.4) | 60.1 (39.2, 88.3) | 62.6 (42.0, 92.5) |
| HOMA-IR | 111 | 1.5 (1.0, 2.1) | 1.7 (1.1, 2.5) | 1.9 (1.2, 2.9) | 2.0 (1.3, 3.0) |
| Lifestyle factors | |||||
| Current tobacco use | 7 | 5.1 | 10 | 9.0 | 19 |
| Tobacco use, pack-years | 36 | 0.0 (0.0, 6.2) | 0.0 (0.0, 10.0) | 0.0 (0.0, 13.2) | 1.0 (0.0, 21.8) |
| Weekly exercise frequency | 26 | ||||
| None | 21 | 22 | 30 | 34 | |
| 1–3 times | 42 | 40 | 35 | 37 | |
| ≥4 times | 37 | 38 | 35 | 29 | |
| Current alcohol use | 23 | ||||
| None | 51 | 51 | 57 | 57 | |
| Moderate | 43 | 44 | 37 | 37 | |
| Heavy | 5.1 | 4.2 | 5.8 | 6.6 | |
| Southern diet score | 389 | −0.3 (1.0) | −0.2 (1.0) | −0.1 (0.9) | 0.2 (1.1) |
| Total energy intake, kcal | 389 | 1,594 (1,216, 2,078) | 1,633 (1,297, 2,144) | 1,528 (1,180, 2,086) | 1,620 (1,225, 2,106) |
Continuous variables are presented as mean (SD) or median (IQR) based on the skewness of the variable; proportions are presented as percentage. Percentages may not add to 100% because of rounding.
*
For rows n and Weighted n, column indicates all; for remaining rows, column indicates n missing.
†
Participants missing either antihypertensive medication use status or blood pressure measurement remained in the sample only if they met the elevated blood pressure criterion of the metabolic syndrome definition through the other.