Table 1.
Baseline characteristics of quantiles of Systemic immune inflammation index (SII) among the general adult population in the National Health and Nutrition Examination Survey (NHANES), 1999–2018.
| Variables | Quartiles of SII | p Value | |||
|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | ||
| Participants, n | 10,718 | 10,720 | 10,720 | 10,717 | |
| Age, years | 44.47 (18.10) | 44.44 (17.80) | 44.21 (17.79) | 44.69 (18.54) | 0.298 |
| Male, % | 5895 (55.0) | 5453 (50.9) | 5108 (47.6) | 4627 (43.2) | <0.001 |
| Race/ethnicity, % | <0.001 | ||||
| Mexican American | 1736 (16.2) | 2210 (20.6) | 2323 (21.7) | 2309 (21.5) | |
| Other Hispanic | 862 (8.0) | 1000 (9.3) | 961 (9.0) | 904 (8.4) | |
| Non-Hispanic White | 3125 (29.2) | 4186 (39.0) | 4655 (43.4) | 5063 (47.2) | |
| Non-Hispanic Black | 3755 (35.0) | 2170 (20.2) | 1776 (16.6) | 1586 (14.8) | |
| Other race | 1240 (11.6) | 1154 (10.8) | 1005 (9.4) | 855 (8.0) | |
| Education level, % | 0.001 | ||||
| Below high school | 2906 (27.1) | 2929 (27.3) | 2931 (27.3) | 2949 (27.5) | |
| High school | 2336 (21.8) | 2305 (21.5) | 2449 (22.8) | 2543 (23.7) | |
| Above high school | 5476 (51.1) | 5486 (51.2) | 5340 (49.8) | 5225 (48.8) | |
| Poverty, % | 2358 (22.0) | 2223 (20.7) | 2274 (21.2) | 2388 (22.3) | 0.022 |
| Smoking status, % | <0.001 | ||||
| Never smokers | 6451 (60.2) | 6386 (59.6) | 6240 (58.2) | 5831 (54.4) | |
| Former smokers | 2127 (19.8) | 2185 (20.4) | 2145 (20.0) | 2239 (20.9) | |
| Current smokers | 2140 (20.0) | 2149 (20.0) | 2335 (21.8) | 2647 (24.7) | |
| Drinking status, % | <0.001 | ||||
| Non-drinkers | 2430 (22.7) | 2436 (22.7) | 2242 (20.9) | 2446 (22.8) | |
| Low-to-moderate drinkers | 7488 (69.9) | 7516 (70.1) | 7656 (71.4) | 7345 (68.5) | |
| Heavy drinkers | 800 (7.5) | 768 (7.2) | 822 (7.7) | 926 (8.6) | |
| BMI status, % | 0.011 | ||||
| <25.0 | 3841 (35.8) | 3454 (32.2) | 3237 (30.2) | 3340 (31.2) | |
| 25.0–29.9 | 3603 (33.6) | 3677 (34.3) | 3566 (33.3) | 3241 (30.2) | |
| >29.9 | 3274 (30.5) | 3589 (33.5) | 3917 (36.5) | 4136 (38.6) | |
| Physical activity, % | <0.001 | ||||
| Inactive | 2475 (23.1) | 2482 (23.2) | 2632 (24.6) | 2922 (27.3) | |
| Insufficiently active | 3786 (35.3) | 3988 (37.2) | 4150 (38.7) | 4133 (38.6) | |
| Active | 4457 (41.6) | 4250 (39.6) | 3938 (36.7) | 3662 (34.2) | |
| Energy intake, kcal/day | 1984.00 [1473.37, 2600.50] | 1977.00 [1494.00, 2595.00] | 1960.50 [1472.00, 2568.62] | 1922.50 [1462.50, 2535.50] | <0.001 |
| eGFR, mL/min/1.73 m2 | 100.52 (22.87) | 100.14 (22.58) | 100.33 (23.06) | 99.22 (24.54) | <0.001 |
| ALT, U/L | 21.00 [16.00, 29.00] | 21.00 [16.00, 29.00] | 21.00 [16.00, 29.00] | 20.00 [15.00, 27.00] | <0.001 |
| AST, U/L | 23.00 [20.00, 28.00] | 23.00 [19.00, 27.00] | 22.00 [19.00, 27.00] | 22.00 [18.00, 26.00] | <0.001 |
| Hypertension, % | 2837 (26.5) | 2788 (26.0) | 2859 (26.7) | 3110 (29.0) | <0.001 |
| Diabetes, % | 905 (8.4) | 966 (9.0) | 875 (8.2) | 1030 (9.6) | 0.001 |
| WBC count, 103/μL | 5.80 [4.90, 6.90] | 6.60 [5.60, 7.70] | 7.20 [6.10, 8.40] | 8.20 [6.90, 9.90] | <0.001 |
| Neutrophils count, 103/μL | 2.80 [2.20, 3.40] | 3.60 [3.00, 4.30] | 4.30 [3.60, 5.10] | 5.50 [4.60, 6.70] | <0.001 |
| Monocyte count, 103/μL | 0.50 [0.40, 0.60] | 0.50 [0.40, 0.60] | 0.50 [0.40, 0.70] | 0.60 [0.50, 0.70] | <0.001 |
| Lymphocyte count, 103/μL | 2.30 [1.90, 2.80] | 2.20 [1.80, 2.60] | 2.00 [1.70, 2.50] | 1.80 [1.50, 2.30] | <0.001 |
| Platelet count, 103/μL | 211.00 [180.00, 243.00] | 238.00 [209.00, 273.00] | 260.00 [227.00, 297.00] | 294.00 [253.00, 342.00] | <0.001 |
| SIRI | 0.57 [0.42, 0.77] | 0.87 [0.68, 1.10] | 1.14 [0.89, 1.45] | 1.69 [1.25, 2.31] | <0.001 |
Normally distributed continuous variables were described as means and SD, and continuous variables without a normal distribution were presented as medians [interquartile ranges]. Categorical variables are presented as numbers (percentages). eGFR, estimated glomerular filtration rate; ALT, alanine aminotransferase; AST, aspartate aminotransferase; WBC, white blood cell; SII, systemic immune-inflammatory index; SIRI, systemic inflammatory response index.