Table 1.
Participant characteristics by quartiles of inflammatory biomarkers, NHANES 1999–2006 (n = 2483).
| Variables | Overall | CRP (mg/L) | p-Value | SII (×109 cells/L) | p-Value | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n (%) | 2483 (100) | <1.2 | 1.2–2.5 | 2.6–5.2 | ≥5.3 | <365.7 | 365.7–503.6 | 503.7–704.0 | ≥704.1 | ||
| 599 (24.1) | 636 (25.6) | 619 (24.9) | 629 (25.4) | 620 (25.0) | 623 (25.1) | 619 (24.9) | 621 (25.0) | ||||
| Ag e (years) | |||||||||||
| 60–69 | 1319 (53.1) | 319 (53.3) | 315 (49.5) | 324 (52.3) | 361 (57.4) | 0.19 | 357 (57.6) | 366 (58.8) | 293 (47.4) | 303 (48.8) | <0.01 |
| 70–79 | 756 (30.5) | 183 (30.5) | 204 (32.1) | 190 (30.7) | 179 (28.5) | 181 (29.2) | 178 (28.5) | 202 (32.6) | 195 (31.4) | ||
| ≥80 | 408 (16.4) | 97 (16.2) | 117 (18.4) | 105 (17.0) | 89 (14.1) | 82 (13.2) | 79 (12.7) | 124 (20.0) | 123 (19.8) | ||
| Sex | |||||||||||
| Female | 1292 (52.0) | 247 (41.2) | 304 (47.8) | 349 (56.4) | 392 (62.3) | <0.01 | 320 (51.6) | 315 (50.6) | 347 (56.1) | 310 (49.9) | 0.13 |
| Male | 1191 (48.0) | 352 (58.8) | 332 (52.2) | 270 (43.6) | 237 (37.7) | 300 (48.4) | 308 (49.4) | 272 (43.9) | 311 (50.1) | ||
| Race | |||||||||||
| White | 1408 (56.7) | 345 (57.6) | 400 (62.9) | 343 (55.4) | 320 (50.9) | <0.01 | 272 (43.9) | 346 (55.5) | 379 (61.2) | 411 (66.2) | <0.01 |
| Black | 400 (16.1) | 82 (13.7) | 81 (13.7) | 98 (15.3) | 139 (22.1) | 170 (27.4) | 86 (13.8) | 78 (12.6) | 66 (10.6) | ||
| Other | 675 (27.2) | 172 (28.7) | 155 (24.4) | 178 (28.8) | 170 (27.0) | 178 (28.7) | 191 (30.7) | 162 (26.2) | 144 (23.2) | ||
| Education | |||||||||||
| High school or less | 1555 (62.6) | 343 (57.3) | 381 (59.9) | 410 (66.2) | 421 (66.9) | <0.01 | 396 (63.9) | 396 (63.5) | 393 (63.5) | 370 (59.6) | 0.76 |
| Attended college | 504 (20.3) | 117 (19.5) | 129 (20.3) | 121 (19.6) | 137 (21.8) | 123 (19.8) | 122 (19.6) | 123 (19.9) | 136 (21.9) | ||
| Graduated from college | 423 (17.1) | 139 (23.2) | 126 (19.8) | 88 (14.2) | 71 (11.3) | 101 (16.3) | 105 (16.9) | 103 (16.6) | 115 (18.5) | ||
| Marital status | |||||||||||
| Not married | 896 (36.1) | 198 (33.1) | 203 (31.9) | 227 (36.7) | 268 (42.6) | <0.01 | 221 (35.7) | 205 (32.9) | 224 (36.2) | 246 (39.6) | 0.11 |
| Married or living with partner | 1587 (63.9) | 401 (66.9) | 433 (68.1) | 392 (63.3) | 361 (57.4) | 399 (64.4) | 418 (67.1) | 395 (63.8) | 375 (60.4) | ||
| Smoking status | |||||||||||
| Never | 1161 (46.8) | 304 (50.8) | 279 (43.8) | 283 (45.7) | 295 (46.9) | 0.02 | 311 (50.1) | 304 (48.8) | 269 (43.5) | 277 (44.6) | 0.06 |
| Current | 310 (12.5) | 51 (8.5) | 82 (12.8) | 86 (13.9) | 91 (14.5) | 70 (11.3) | 63 (10.1) | 86 (13.9) | 91 (14.6) | ||
| Former | 1012 (40.8) | 244 (40.7) | 275 (43.2) | 250 (40.4) | 243 (38.6) | 239 (38.6) | 256 (41.1) | 264 (42.6) | 253 (40.7) | ||
| RFM | |||||||||||
| Low | 218 (8.8) | 91 (15.1) | 57 (8.9) | 35 (5.7) | 35 (5.6) | <0.01 | 58 (9.3) | 50 (8.0) | 52 (8.4) | 58 (9.3) | 0.39 |
| Moderate | 672 (27.1) | 227 (37.9) | 188 (29.6) | 141 (22.9) | 116 (18.4) | 190 (30.7) | 170 (27.3) | 154 (24.9) | 158 (25.4) | ||
| High | 1126 (45.4) | 228 (38.1) | 305 (48.0) | 304 (49.1) | 289 (45.9) | 270 (43.5) | 280 (45.0) | 286 (46.2) | 290 (46.7) | ||
| Very high | 467 (18.8) | 53 (8.9) | 86 (13.5) | 139 (22.4) | 189 (30.1) | 102 (16.5) | 123 (19.7) | 127 (20.5) | 115 (18.5) | ||
|
Regular physical
activity |
|||||||||||
| No | 1207 (48.6) | 255 (42.6) | 286 (45.0) | 307 (49.6) | 359 (57.1) | <0.01 | 287 (46.3) | 297 (47.7) | 309 (49.9) | 314 (50.6) | 0.40 |
| Yes | 1276 (51.4) | 344 (57.4) | 350 (55.0) | 312 (50.4) | 270 (42.9) | 333 (53.7) | 326 (52.3) | 310 (50.1) | 307 (49.4) | ||
| Alcohol drinking | |||||||||||
| No | 960 (38.6) | 219 (36.5) | 227 (35.7) | 245 (39.6) | 269 (42.8) | 0.02 | 266 (42.9) | 248 (39.8) | 218 (35.2) | 228 (36.7) | <0.01 |
| ≤1 drink/day | 593 (23.9) | 162 (27.1) | 168 (26.4) | 141 (22.8) | 122 (19.4) | 122 (19.7) | 141 (22.6) | 190 (30.7) | 140 (22.5) | ||
| >1 drink/day | 930 (37.5) | 218 (36.4) | 241 (37.9) | 233 (37.6) | 238 (37.8) | 232 (37.4) | 234 (37.6) | 211 (34.1) | 253 (40.8) | ||
| Carbohydrate intake (g/day) | |||||||||||
| <153.9 | 621 (25.0) | 111 (18.5) | 152 (26.3) | 156 (25.2) | 202 (32.1) | <0.01 | 162 (26.1) | 158 (25.5) | 142 (22.9) | 159 (25.6) | 0.65 |
| 153.9–205.8 | 593 (23.9) | 143 (23.3) | 148 (23.3) | 157 (25.3) | 145 (23.1) | 141 (22.7) | 160 (25.7) | 147 (23.8) | 145 (23.4) | ||
| 205.9–268.9 | 643 (25.9) | 155 (25.9) | 173 (27.2) | 160 (25.9) | 155 (24.6) | 159 (25.7) | 156 (25.0) | 178 (28.8) | 150 (24.1) | ||
| ≥269.0 | 626 (25.2) | 190 (31.7) | 163 (25.6) | 146 (23.6) | 127 (20.2) | 158 (25.5) | 149 (23.9) | 152 (24.6) | 167 (26.9) | ||
| Total fat intake (g/day) | |||||||||||
| <42.2 | 624 (25.1) | 134 (22.4) | 153 (24.1) | 157 (25.4) | 180 (28.6) | 0.19 | 162 (26.1) | 161 (25.8) | 149 (24.1) | 152 (24.5) | 0.83 |
| 42.2–60.1 | 614 (24.7) | 156 (26.0) | 143 (22.5) | 155 (25.0) | 160 (25.5) | 152 (24.5) | 164 (26.3) | 152 (24.6) | 146 (23.5) | ||
| 60.2–82.9 | 631 (25.4) | 151 (25.2) | 170 (26.7) | 155 (25.0) | 155 (24.6) | 158 (25.5) | 142 (22.8) | 160 (25.8) | 171 (27.5) | ||
| ≥83.0 | 614 (24.7) | 158 (26.4) | 170 (26.7) | 152 (24.6) | 134 (21.3) | 148 (23.9) | 156 (25.1) | 158 (25.5) | 152 (24.5) | ||
| Protein intake (g/day) | |||||||||||
| < 48.3 | 617 (24.9) | 115 (19.2) | 154 (24.2) | 165 (26.6) | 183 (29.1) | <0.01 | 142 (22.9) | 161 (25.8) | 152 (24.6) | 162 (26.1) | 0.78 |
| 48.3–65.4 | 615 (24.8) | 143 (23.9) | 139 (21.9) | 160 (25.9) | 173 (27.5) | 150 (24.2) | 146 (23.4) | 157 (25.4) | 162 (26.1) | ||
| 65.5–85.1 | 630 (25.3) | 166 (27.7) | 165 (25.9) | 157 (25.4) | 142 (22.6) | 158 (25.5) | 163 (26.2) | 162 (26.2) | 147 (23.6) | ||
| ≥85.2 | 621 (25.0) | 175 (29.2) | 178 (28.0) | 137 (22.1) | 131 (20.8) | 170 (27.4) | 153 (24.6) | 148 (23.9) | 150 (24.2) | ||
| Energy intake (kcal/day) | |||||||||||
| < 1259.0 | 622 (25.1) | 116 (19.4) | 161 (25.3) | 159 (25.7) | 186 (29.6) | <0.01 | 154 (24.8) | 174 (27.9) | 146 (23.6) | 148 (23.8) | 0.84 |
| 1259.0–1654.3 | 592 (23.8) | 145 (24.2) | 130 (20.4) | 158 (25.5) | 159 (25.3) | 149 (24.0) | 140 (22.5) | 146 (23.6) | 157 (25.3) | ||
| 1654.4–2133.7 | 641 (25.8) | 163 (27.2) | 174 (27.4) | 151 (24.4) | 153 (24.3) | 163 (26.2) | 154 (24.7) | 167 (26.9) | 157 (25.3) | ||
| ≥2133.8 | 628 (25.3) | 175 (29.2) | 171 (26.9) | 151 (24.4) | 131 (20.8) | 154 (24.8) | 155 (24.9) | 160 (25.9) | 159 (25.6) | ||
| Multimorbidity * | |||||||||||
| No | 894 (36.0) | 247 (41.2) | 217 (34.1) | 226 (36.5) | 204 (32.4) | <0.01 | 238 (38.4) | 260 (41.7) | 202 (32.6) | 194 (31.2) | <0.01 |
| Yes | 1589 (64.0) | 352 (58.8) | 419 (65.9) | 393 (63.5) | 425 (67.6) | 382 (61.6) | 363 (58.3) | 417 (67.4) | 427 (68.8) | ||
| Respiratory disease § | |||||||||||
| No | 2219 (89.4) | 559 (93.3) | 572 (89.9) | 543 (87.7) | 545 (86.6) | <0.01 | 569 (91.8) | 572 (91.8) | 548 (88.5) | 530 (85.4) | <0.01 |
| Yes | 264 (10.6) | 40 (6.7) | 64 (10.1) | 76 (12.3) | 84 (13.4) | 51 (8.2) | 51 (8.2) | 71 (11.5) | 91 (14.6) | ||
| Hypertension | |||||||||||
| No | 906 (36.5) | 245 (40.9) | 237 (37.3) | 219 (35.4) | 205 (32.6) | 0.02 | 234 (37.7) | 239 (38.4) | 233 (37.6) | 200 (32.2) | 0.09 |
| Yes | 1577 (63.5) | 354 (59.1) | 399 (62.7) | 400 (64.6) | 424 (67.4) | 386 (62.3) | 384 (61.6) | 386 (62.4) | 421 (67.8) | ||
| CVD † | |||||||||||
| No | 1932 (77.8) | 454 (75.8) | 488 (76.7) | 512 (82.7) | 478 (76.0) | <0.01 | 493 (79.5) | 494 (79.3) | 479 (77.4) | 466 (75.0) | 0.19 |
| Yes | 551 (22.2) | 145 (24.2) | 148 (23.3) | 107 (17.3) | 151 (24.0) | 127 (20.5) | 129 (20.7) | 140 (22.6) | 155 (25.0) | ||
| Diabetes | |||||||||||
| No | 1949 (78.5) | 466 (77.8) | 513 (80.7) | 474 (76.6) | 496 (78.9) | 0.34 | 483 (77.9) | 478 (76.7) | 500 (80.8) | 488 (78.6) | 0.36 |
| Yes | 534 (21.5) | 133 (22.2) | 123 (19.3) | 145 (23.4) | 133 (21.1) | 137 (22.1) | 145 (23.3) | 119 (19.2) | 133 (21.4) | ||
|
Chronic kidney
disease |
|||||||||||
| No | 2387 (96.1) | 586 (97.8) | 612 (96.2) | 597 (96.5) | 592 (94.1) | <0.01 | 598 (96.5) | 606 (97.3) | 596 (96.3) | 587 (94.5) | 0.08 |
| Yes | 96 (3.9) | 13 (2.2) | 24 (3.8) | 22 (3.5) | 37 (5.9) | 22 (3.5) | 17 (2.7) | 23 (3.7) | 34 (5.5) | ||
| Arthritis | |||||||||||
| No | 1159 (46.7) | 318 (53.1) | 283 (44.5) | 290 (46.9) | 268 (42.6) | <0.01 | 306 (49.4) | 301 (48.3) | 265 (43.8) | 287 (46.2) | 0.10 |
| Yes | 1324 (53.3) | 281 (46.9) | 353 (55.5) | 329 (53.1) | 361 (57.4) | 314 (50.6) | 322 (51.7) | 354 (57.2) | 334 (53.8) | ||
| Osteoporosis | |||||||||||
| No | 2,163 (87.1) | 526 (87.2) | 551 (86.6) | 535 (86.4) | 551 (87.6) | 0.85 | 552 (89.0) | 548 (88.0) | 526 (85.0) | 537 (86.5) | 0.16 |
| Yes | 320 (12.9) | 73 (12.8) | 85 (13.4) | 84 (13.6) | 78 (12.4) | 68 (11.0) | 75 (12.0) | 93 (15.0) | 84 (13.5) | ||
| Cancer | |||||||||||
| No | 1989 (80.1) | 470 (78.5) | 502 (78.9) | 499 (80.6) | 518 (82.4) | 0.30 | 515 (83.1) | 505 (81.1) | 482 (77.9) | 487 (78.4) | 0.08 |
| Yes | 494 (19.9) | 129 (21.5) | 134 (21.1) | 120 (19.4) | 111 (17.6) | 105 (16.9) | 118 (18.9) | 137 (22.1) | 134 (21.6) | ||
Abbreviations—CRP: C-reactive protein; CVD: cardiovascular diseases; RFM: relative fat mass; SII: systemic immune-inflammation index. Column percentages are reported in the table.* Comorbidities include respiratory diseases, CVD, chronic kidney diseases, osteoporosis, diabetes, arthritis, hypertension, and cancer. § Respiratory diseases include emphysema and chronic bronchitis. † CVD (cardiovascular diseases) include heart attack, coronary heart disease, stroke, and congestive heart failure. RFM was categorized based cutoffs validated in prior research to reflect low (female: <35%; male: <25%), moderate (female: 35–39.9%; male: 25–29.9%), high (female: 40–44.9%; male: 30–34.9%), and very high (female: ≥45%; male: ≥35%) body fat.