Table 3.
Characteristics of the serum 25(OH)D and cognition study population, National Health and Nutrition Examination Survey (NHANES) 2011–2014 (N = 2735).
| CERAD Test | Animal Fluency Test | Digit Symbol Test | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Number of Subjects (N) | Normal Cognitive Performance | Low Cognitive Performance | p-Value | Normal Cognitive Performance | Low Cognitive Performance | p-Value | Normal Cognitive Performance | Low Cognitive Performance | p-Value | |
| Number of subjects (%) | 2015(73.7) | 720(26.3) | 1914(70.0) | 821(30.0) | 2014(73.6) | 721(26.4) | ||||
| Age (%) 1 | 2735 | 0.258 | 0.449 | 0.963 | ||||||
| ≥60 years | 1110(55.1) | 379(52.6) | 1033(54.0) | 456(55.0) | 1097(54.5) | 392(54.4) | ||||
| ≥70 years | 905(44.9) | 341(47.4) | 881(46.0) | 365(44.5) | 917(45.5) | 329(45.6) | ||||
| Gender(%) 1 | 2735 | <0.01 | 0.460 | <0.01 | ||||||
| Male | 911(45.2) | 431(59.9) | 948(49.5) | 394(48.0) | 941(46.7) | 401(55.6) | ||||
| Female | 1104(54.8) | 289(40.1) | 966(50.5) | 427(52.0) | 1073(53.3) | 320(44.4) | ||||
| Race(%) 1 | 2735 | <0.01 | <0.01 | <0.01 | ||||||
| Mexican American | 160(7.9) | 81(11.3) | 169(8.8) | 72(8.8) | 137(6.8) | 104(14.4) | ||||
| Other Hispanic | 177(8.8) | 102(14.2) | 173(9.0) | 106(12.9) | 138(6.9) | 141(19.6) | ||||
| Non-Hispanic White | 1032(51.2) | 190(40.3) | 1057(55.2) | 265(32.3) | 1141(56.7) | 181(25.1) | ||||
| Non-Hispanic Black | 441(21.9) | 189(26.3) | 359(18.8) | 271(33.0) | 380(18.9) | 250(34.7) | ||||
| Other races | 205(10.2) | 58(8.1) | 156(8.2) | 107(13.0) | 218(10.8) | 45(6.2) | ||||
| Educational level (%) 1 | 2735 | <0.01 | <0.01 | <0.01 | ||||||
| Below high school | 382(19.0) | 304(42.2) | 369(19.3) | 317(38.6) | 276(13.7) | 410(56.9) | ||||
| High school | 475(23.6) | 175(24.3) | 435(22.7) | 215(26.2) | 489(24.3) | 161(22.3) | ||||
| Above high school | 1158(57.5) | 241(33.5) | 1110(58.0) | 289(35.2) | 1249(62.0) | 150(20.8) | ||||
| Marital status (%) 1 | 2733 | 0.089 | 0.020 | <0.01 | ||||||
| Married/living with partner | 1189(59.1) | 399(55.4) | 11139(59.5) | 449(54.8) | 1226(60.9) | 392(50.3) | ||||
| widowers/divorced/separated/never married | 824(40.9) | 321(44.6) | 774(40.5) | 371(45.2) | 78(39.1) | 358(49.7) | ||||
| Poverty-income ratio (%) 1 | 2509 | 0.199 | 0.928 | 0.572 | ||||||
| ≤1.00 | 318(17.1) | 96(14.9) | 292(16.5) | 122(16.4) | 312(16.7) | 102(15.8) | ||||
| ≥1.00 | 1546(82.9) | 549(85.1) | 1473(83.5) | 622(83.6) | 1551(83.3) | 544(84.2) | ||||
| Body mass index (%) 1 | 2697 | 0.178 | 0.449 | 0.675 | ||||||
| <25 kg/m2 | 535(26.9) | 205(29.0) | 508(26.8) | 232(29.0) | 543(27.2) | 197(28.2) | ||||
| <30 kg/m2 | 699(35.1) | 360(36.8) | 685(36.1) | 274(31.1) | 706(35.3) | 253(36.2) | ||||
| ≥30 kg/m2 | 757(38.0) | 241(34.1) | 705(37.1) | 293(36.7) | 749(37.5) | 249(35.6) | ||||
| Physical activity level (%) 1 | 2735 | <0.01 | <0.01 | <0.01 | ||||||
| Moderate and high | 892(44.3) | 258(35.8) | 889(46.4) | 261(31.8) | 946(47.0) | 204(28.3) | ||||
| Low | 1123(55.7) | 462(64.2) | 1025(53.6) | 560(68.2) | 1068(53.0) | 517(71.7) | ||||
| Season of exam (%) 1 | 2735 | 0.877 | 0.859 | 0.011 | ||||||
| November-April | 914(45.4) | 329(45.7) | 872(45.6) | 371(45.2) | 886(44.0) | 357(49.5) | ||||
| May-October | 1101(54.6) | 391(54.3) | 1042(54.4) | 450(54.8) | 1128(56.0) | 364(50.5) | ||||
| Smoking status (%) 1 | 2733 | 1013(50.3) | 369(51.3) | 0.669 | 969(50.7) | 413(50.3) | 0.857 | 1005(50.0) | 377(52.3) | 0.281 |
| Hypertension (%)1 | 2733 | 1381(68.6) | 514(71.5) | 0.145 | 1283(67.1) | 612(74.5) | <0.01 | 1357(67.4) | 538(74.6) | <0.01 |
| Diabetes (%) 1 | 2735 | 529(26.3) | 230(31.9) | 0.003 | 473(24.7) | 286(34.8) | <0.01 | 480(23.8) | 279(38.7) | <0.01 |
| Stroke (%) | 2730 | 115(5.7) | 72(10.0) | <0.01 | 104(5.4) | 83(10.1) | <0.01 | 105(5.2) | 82(11.4) | <0.01 |
| Had at least 12 alcohol drinks/year (%) 1 | 2689 | 1376(69.2) | 466(66.6) | 0.201 | 1339(70.9) | 503(63.8) | <0.01 | 1413(70.9) | 429(61.5) | <0.01 |
| Serum total 25(OH)D (nmol/L) 2 | 2735 | 78.17(32.02) | 72.55(30.20) | <0.01 | 78.3(31.1) | 72.68(32.84) | <0.01 | 79.06(31.33) | 69.72(31.78) | <0.01 |
| Serum 25(OH)D3 (nmol/L) 2 | 2735 | 71.38(32.31) | 65.32(29.33) | <0.01 | 71.90(31.55) | 64.91(31.37) | <0.01 | 72.43(31.62) | 62.04(30.73) | <0.01 |
| Serum 25(OH)D2 (nmol/L) 1 | 2735 | 0.076 | 0.159 | 0.45 | ||||||
| ≤1.45 | 1512(75.0) | 516(71,7) | 1434(74.9) | 594(72.4) | 1501(74.5) | 527(73.1) | ||||
| >1.45 | 503(25.0) | 204(28.3) | 480(25.1) | 227(27.6) | 513(25.5) | 194(26.9) | ||||
Data are number of subjects (percentage) or medians (interquartile ranges); 1 Chi-square was used to compare the percentage between participants with and without low cognitive performance; 2 Mann–Whitney U test was applied to compare the median values between participants with and without low cognitive performance.