Table 1. Baseline Characteristics of the DO-HEALTH Study Samplea.
| Characteristics | Vitamin D | Omega-3s | Exercise | Overall total (n = 2157) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vitamin D (n = 1076) | No vitamin D (n = 1081) | SMD | Omega-3s (n = 1073) | No omega-3s (n = 1084) | SMD | Strength-training exercise (n = 1081) | Control exercise (n = 1076)b | SMD | ||
| Age, mean (SD), y | 75.0 (4.5) | 74.9 (4.4) | 0.03 | 74.7 (4.3) | 75.2 (4.6) | 0.10 | 75.0 (4.5) | 74.9 (4.4) | 0.02 | 74.9 (4.4) |
| Age categories, No. (%), y | 0.05 | 0.10 | 0.02 | |||||||
| 70-74 | 606 (56.3) | 631 (58.4) | 635 (59.2) | 602 (55.5) | 622 (57.5) | 615 (57.2) | 1237 (57.3) | |||
| 75-84 | 417 (38.8) | 405 (37.5) | 398 (37.1) | 424 (39.1) | 408 (37.7) | 414 (38.5) | 822 (38.1) | |||
| ≥85 | 53 (4.9) | 45 (4.2) | 40 (3.7) | 58 (5.4) | 51 (4.7) | 47 (4.4) | 98 (4.5) | |||
| BMI, mean (SD)c | 26.5 (4.4) [n = 1075] | 26.2 (4.2) | 0.08 | 26.3 (4.2) [n = 1072] | 26.4 (4.3) | 0.02 | 26.3 (4.2) | 26.4 (4.4) [n = 1075] | 0.02 | 26.3 (4.3) [n = 2156] |
| Sex, No. (%) | ||||||||||
| Women | 667 (62.0) | 664 (61.4) | 0.01 | 668 (62.3) | 663 (61.2) | 0.02 | 665 (61.5) | 666 (61.9) | 0.01 | 1331 (61.7) |
| Men | 409 (38.0) | 417 (38.6) | 405 (37.7) | 421 (38.8) | 416 (38.5) | 410 (38.1) | 826 (38.3) | |||
| Education, mean (SD), y | 12.7 (4.4) [n = 1074] | 12.6 (4.2) [n = 1081] | 0.02 | 12.6 (4.2) [n = 1071] | 12.7 (4.4) [n = 1084] | 0.02 | 12.6 (4.2) [n = 1079] | 12.6 (4.4) [n = 1076] | 0.00 | 12.6 (4.3) [n = 2155] |
| MoCA score, mean (SD)d | 25.8 (3.3) [n = 1074] | 25.5 (3.4) [n = 1079] | 0.07 | 25.6 (3.4) [n = 1072] | 25.7 (3.3) [n = 1081] | 0.01 | 25.7 (3.3) [n = 1080] | 25.6 (3.4) [n = 1073] | 0.01 | 25.7 (3.4) [n = 2153] |
| MMSE score, mean (SD)e | 28.5 (1.5) | 28.5 (1.5) | 0.02 | 28.5 (1.5) | 28.5 (1.5) | 0.05 | 28.4 (1.5) | 28.5 (1.5) | 0.06 | 28.5 (1.5) |
| Comorbidity score, mean (SD)f | 3.3 (3.1) [n = 1075] | 3.3 (3.0) [n = 1080] | 0.02 | 3.3 (3.1) [n = 1072] | 3.3 (2.9) [n = 1083] | 0.00 | 3.2 (3.0) [n = 1079] | 3.4 (3.1) | 0.06 | 3.3 (3.0) [n = 2155] |
| Self-reported hypertension, No. (%) | 427 (39.7) [n = 1075] | 417 (38.6) [n = 1080] | 0.02 | 414 (38.6) [n = 1072] | 430 (39.7) [n = 1083] | 0.02 | 405 (37.5) [n = 1079] | 439 (40.8) | 0.07 | 844 (39.2) [n = 2155] |
| Use of antihypertensive drugs, No. (%) | 548 (50.9) | 521 (48.2) | 0.06 | 509 (47.4) | 560 (51.7) | 0.09 | 516 (47.7) | 553 (51.4) | 0.07 | 1069 (49.6) |
| Health-related quality of life score, median (IQR)g | 0.90 (0.89-1.00) [n = 1075] | 0.91 (0.89-1.00) [n = 1079] | 0.01 | 1.00 (0.89-1.00) [n = 1072] | 0.89 (0.89-1.00) [n = 1082] | 0.10 | 0.91 (0.89-1.00) [n = 1080] | 0.89 (0.89-1.00) [n = 1074] | 0.03 | 0.91 (0.89-1.00) [n = 2154] |
| Self-rated health score, mean (SD)h | 81.0 (15.1) [n = 1075] | 81.5 (14.7) [n = 1079] | 0.04 | 81.2 (14.9) [n = 1072] | 81.2 (14.9) [n = 1082] | <0.001 | 80.9 (14.8) [n = 1080] | 81.5 (15.1) [n = 1074] | 0.04 | 81.2 (14.9) [n = 2154] |
| SPPB score, median (IQR)i | 12.0 (10.0-12.0) [n = 1073] | 11.0 (10.0-12.0) [n = 1080] | 0.03 | 11.0 (10.0-12.0) [n = 1071] | 11.0 (10.0-12.0) [n = 1082] | 0.02 | 11.0 (10.0-12.0) [n = 1080] | 11.0 (10.0-12.0) [n = 1073] | 0.03 | 11.0 (10.0-12.0) [n = 2153] |
| Prior fall, No. (%)j | 446 (41.4) | 457 (42.3) | 0.02 | 441 (41.1) | 462 (42.6) | 0.03 | 450 (41.6) | 453 (42.1) | 0.01 | 903 (41.9) |
| Repeated chair test, median (IQR), sk | 10.6 (8.8-13.4) [n = 1066] | 10.9 (8.8-13.5) [n = 1065] | 0.03 | 10.6 (8.8-13.4) [n = 1056] | 10.8 (8.8-13.6) [n = 1075] | 0.02 | 10.7 (8.9-13.6) [n = 1069] | 10.8 (8.7-13.4) [n = 1062] | 0.06 | 10.7 (8.8-13.5) [n = 2131] |
| Vitamin D supplement use ≥800 IU/d, No. (%) | 110 (10.2) | 126 (11.7) | 0.05 | 123 (11.5) | 113 (10.4) | 0.03 | 127 (11.7) | 109 (10.1) | 0.05 | 236 (10.9) |
| Vitamin D severe deficiency (<12 ng/mL), No. (%) | 127 (11.9) [n = 1066] | 114 (10.6) [n = 1074] | 0.04 | 128 (12.0) [n = 1063] | 113 (10.5) [n = 1077] | 0.05 | 110 (10.3) [n = 1071] | 131 (12.3) [n = 1069] | 0.06 | 241 (11.3) [n = 2140] |
| Vitamin D deficiency (<20 ng/mL), No. (%) | 427 (40.1) [n = 1066] | 445 (41.4) [n = 1074] | 0.03 | 422 (39.7) [n = 1063] | 450 (41.8) [n = 1077] | 0.04 | 422 (39.4) [n = 1071] | 450 (42.1) [n = 1069] | 0.06 | 872 (40.7) [n = 2140] |
| Serum 25-hydroxyvitamin D concentration, mean (SD), ng/mLl | 22.4 (8.4) [n = 1066] | 22.4 (8.5) [n = 1074] | 0.01 | 22.4 (8.4) [n = 1063] | 22.4 (8.4) [n = 1077] | 0.00 | 22.8 (8.6) [n = 1071] | 22.0 (8.2) [n = 1069] | 0.10 | 22.4 (8.4) [n = 2140] |
| Serum DHA concentration, mean (SD), μg/mLm | 78.1 (37.9) [n = 1064] | 78.1 (35.9) [n = 1073] | 0.00 | 78.9 (37.2) [n = 1059] | 77.3 (36.6) [n = 1078] | 0.04 | 78.2 (36.5) [n = 1069] | 78.0 (37.4) [n = 1068] | 0.00 | 78.1 (36.9) [n = 2137] |
| Serum EPA concentration, median (IQR), μg/mLm | 24.8 (17.4-37.7) [n = 1064] | 26.2 (18.6-37.7) [n = 1073] | 0.02 | 26.1 (18.5-37.7) [n = 1059] | 25.3 (17.6-37.9) [n = 1078] | 0.01 | 25.1 (17.5-37.6) [n = 1069] | 25.9 (18.6-38.1) [n = 1068] | 0.02 | 25.5 (18.1-37.7) [n = 2137] |
| Physical activity level, No. (%)n | 0.10 | 0.05 | 0.05 | |||||||
| None | 207 (19.3) | 168 (15.6) | 190 (17.7) | 185 (17.1) | 179 (16.6) | 196 (18.2) | 375 (17.4) | |||
| 1-2 times per wk | 318 (29.6) | 334 (30.9) | 311 (29.0) | 341 (31.5) | 323 (29.9) | 329 (30.6) | 652 (30.3) | |||
| ≥3 times per wk | 550 (51.2) [n = 1075] | 578 (53.5) [n = 1080] | 570 (53.2) [n = 1071] | 558 (51.5) | 578 (53.5) [n = 1080] | 550 (51.2) [n = 1075] | 1128 (52.3) [n = 2155] | |||
| Physical activity volume, mean (SD), MET-h/wko | 35.4 (32.0) | 38.5 (34.1) [n = 1080] | 0.09 | 38.2 (34.1) [n = 1072] | 35.7 (32.0) | 0.07 | 37.0 (33.4) [n = 1080] | 36.9 (32.7) | 0.00 | 36.9 (33.1) [n = 2156] |
| Current smoking, No. (%) | 63 (5.9) | 63 (5.8) | 0.00 | 64 (6.0) | 62 (5.7) | 0.01 | 58 (5.4) | 68 (6.3) | 0.04 | 126 (5.8) |
| Systolic blood pressure, mean (SD), mm Hg | 144.2 (18.6) [n = 1070] | 142.9 (18.1) [n = 1075] | 0.07 | 143.2 (18.3) [n = 1069] | 143.9 (18.4) [n = 1076] | 0.04 | 143.7 (18.5) [n = 1075] | 143.4 (18.2) [n = 1070] | 0.02 | 143.5 (18.3) [n = 2145] |
| Diastolic blood pressure, mean (SD), mm Hg | 76.0 (10.1) [n = 1070] | 75.7 (10.0) [n = 1075] | 0.03 | 75.8 (9.7) [n = 1069] | 75.9 (10.4) [n = 1076] | 0.01 | 75.9 (10.3) [n = 1075] | 75.8 (9.8) [n = 1070] | 0.01 | 75.9 (10.0) [n = 2145] |
Abbreviations: IQR, interquartile range; SMD, standardized mean difference
Medians and IQRs are presented for variables with skewness >1.5. Percentages are rounded to 1 decimal, which could lead to percentage sums of 100.1% or 99.9%.
Flexibility was the control exercise program.
Body mass index (BMI) was calculated as weight in kilograms divided by height in meters squared. Higher BMI values reflect overweight (≥25) and obesity (≥30).
The Montreal Cognitive Assessment (MoCA) is a screening test for mild cognitive dysfunction and has a range of 0 to 30 points, in which higher scores are better and scores greater than 26 suggest normal cognitive function.
The Mini-Mental State Examination (MMSE) was used to measure cognitive impairment and has a range of 0 to 30 points, in which higher scores are better and scores greater than 24 suggest normal cognitive function.
Comorbidity was measured by the Self-Administered Comorbidity Questionnaire, which assesses current medical comorbidities (12 comorbidities by 3 dimensions: presence, medication, and limitation of activities). It has a range of 0 to 36 points, in which lower scores are better.
Health-related quality of life was assessed by the EuroQol 5 Dimensions 3 Levels (EQ-5D-3L). Scores range from less than 0 to a maximum of 1 point, in which 0 means a health state equivalent to death, negative values are equivalent to a health state worse than death, and 1 is equivalent to perfect health.
Self-rated health was assessed by the EQ-5D-3L vertical visual analog scale, which ranges from 0 to 100 points, in which higher scores are better.
The Short Physical Performance Battery (SPPB) assesses lower extremity function. Scores range from 0 to 12, in which higher scores are better.
Prior fall in the 1-year period before study start.
Repeated chair stands assess reaction time; the score is the time (in seconds) to complete 5 repeated chair stands. It is part of the SPPB, and lower values (less time to complete the stands) are better.
Normal low value for serum 25-hydroxyvitamin D concentration is ≥20 ng/mL.
There is no consensus on normal values for serum docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) concentrations.
Physical activity level was based on the Nurses’ Health Study questionnaire on physical activity.
Weekly volume of physical activity was estimated based on the Nurses’ Health Study questionnaire on physical activity, in which energy expenditure of different activities in metabolic equivalent tasks (METs) of activities based on the Compendium of Physical Activities were summed over the previous week.