Table 1 Baseline characteristics of the NHANES 2017–2018 study sample[N(%)].
From: Association between vitamin C in serum and trouble sleeping based on NHANES 2017–2018
N | No trouble sleeping | Trouble sleeping | χ2 value | P value | |
|---|---|---|---|---|---|
Overall | 3227 | 2289 (70.9) | 938 (29.1) | ||
Gender | |||||
Male | 1585 | 1178 (51.5) | 407 (43.4) | 17.352 | < 0.001 |
Female | 1642 | 1111 (48.5) | 531 (56.6) | ||
Age | |||||
≤ 65 Years | 2469 | 1794 (78.4) | 675 (72.0) | 15.227 | < 0.001 |
> 65 Years | 758 | 495 (21.6) | 263 (28.0) | ||
Race/ethnicity | |||||
Mexican American | 418 | 327 (14.3) | 91 (9.7) | 62.799 | < 0.001 |
Other Hispanic | 296 | 214 (9.3) | 82 (8.7) | ||
Non-Hispanic White | 1191 | 753 (32.9) | 438 (46.7) | ||
Non-Hispanic Black | 748 | 544 (23.8) | 204 (21.7) | ||
Other Race | 574 | 451 (19.7) | 123 (13.1) | ||
Little interest in doing things | |||||
Not at all | 2433 | 1850 (80.8) | 583 (62.2) | 134.576 | < 0.001 |
Several days | 521 | 305 (13.3) | 216 (23.0) | ||
More than half the days | 161 | 84(3.7) | 77(8.2) | ||
Nearly every day | 112 | 50 (2.2) | 62 (6.6) | ||
Feeling depressed | |||||
Not at all | 2468 | 1890 (82.6) | 578 (61.6) | 175.616 | < 0.001 |
Several days | 528 | 298 (13.0) | 230 (24.5) | ||
More than half the days | 133 | 61 (2.7) | 72 (7.7) | ||
Nearly every day | 98 | 40(1.7) | 58 (6.2) | ||
Diabetes | |||||
No | 2718 | 1990 (86.9) | 728 (77.6) | 43.554 | < 0.001 |
Yes | 509 | 299 (13.1) | 210 (22.4) | ||
Hypertension | |||||
No | 2037 | 1609 (70.3) | 428 (45.6) | 173.871 | < 0.001 |
Yes | 1190 | 680 (29.7) | 510 (54.4) | ||
High cholesterol level | |||||
No | 2071 | 1579 (69.0) | 492 (52.5) | 79.079 | < 0.001 |
Yes | 1156 | 710 (31.0) | 446 (47.5) | ||
Weak/failing kidneys | |||||
No | 3113 | 2236 (97.7) | 877 (93.5) | 32.240 | < 0.001 |
Yes | 114 | 53 (2.3) | 61 (6.5) | ||
Vitamin C | |||||
Q1 (≤ 0.554 mg/dL) | 807 | 517 (22.6) | 290 (30.9) | 24.910 | < 0.001 |
Q2(0.555 mg/dL ~ 0.894 mg/dL) | 809 | 593 (25.9) | 216 (23.0) | ||
Q3 (0.895 mg/dL ~ 1.190 mg/dL) | 805 | 594 (26.0) | 211 (22.5) | ||
Q4 (> 1.190 mg/dL) | 806 | 585 (25.5) | 221 (23.6) | ||
