Table 4.
Baseline characteristics of participants by tertiles of serum DHA (n = 1054).
| Characteristics | Tertile 1 | Tertile 2 | Tertile 3 | p 1 | p 2 | |||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | |||
| Number of subjects | 348 | 353 | 353 | |||||
| Serum DHA (μg/mL) | 108.0 | 17.4 | 146.5 | 10.4 | 202.3 | 41.8 | <0.0001 | *, **, *** |
| Men (n, %) | 172, 49.3 | 174, 49.3 | 174, 49.3 | 0.99 | ||||
| Age (years) | 68.9 | 5.4 | 68.6 | 5.6 | 68.4 | 5.4 | 0.47 | |
| Body mass index (kg/m2) | 22.7 | 3.1 | 22.6 | 3.4 | 23.3 | 2.9 | 0.01 | *, ** |
| Alcohol (mL/day) | 6.3 | 12.9 | 7.5 | 13.8 | 8.7 | 14.8 | 0.08 | |
| Physical activity (1000 METs × h/day) |
34.8 | 3.9 | 34.6 | 4.0 | 34.0 | 3.3 | 0.01 | ** |
| Current smoker (n, %) | 59, 17.0 | 70, 19.8 | 57, 16.2 | 0.40 | ||||
| Education | ||||||||
| ≤ 9 years (n, %) | 175, 50.3 | 171, 49.3 | 158, 44.8 | 0.48 | ||||
| 10–12 years (n, %) | 121, 34.8 | 119, 33.7 | 139, 39.4 | |||||
| ≥ 13 years (n, %) | 52, 14.9 | 60, 17.0 | 56, 15.9 | |||||
| Employment | ||||||||
| Unemployed (n, %) | 240, 69.0 | 245, 69.4 | 248, 70.3 | 0.94 | ||||
| Regular employment (n, %) | 69, 19.8 | 63, 17.9 | 69, 19.6 | |||||
| Non-regular employment (n, %) | 39, 11.2 | 45, 12.8 | 36, 10.2 | |||||
| Diseases | ||||||||
| Cancer (n, %) | 23, 6.6 | 19, 5.4 | 16, 4.6 | 0.49 | ||||
| Heart disease (n, %) | 64, 18.4 | 62, 17.6 | 55, 15.6 | 0.60 | ||||
| Stroke (n, %) | 16, 6.9 | 12, 5.0 | 21, 9.4 | 0.19 | ||||
| Hypertension (n, %) | 128, 36.8 | 123, 34.8 | 143, 40.5 | 0.29 | ||||
| Dyslipidemia (n, %) | 54, 15.5 | 67, 19.0 | 107, 30.3 | <0.0001 | ||||
| Diabetes (n, %) | 41, 11.8 | 35, 9.9 | 43, 12.2 | 0.60 | ||||
| Dietary intake | ||||||||
| Fish intake (g/day) | 89.0 | 46.5 | 96.3 | 44.5 | 110.8 | 57.1 | <0.0001 | *, ** |
| Meat intake (g/day) | 49.4 | 29.6 | 51.3 | 32.7 | 52.1 | 32.7 | 0.52 | |
| EPA intake (mg/day) | 276.6 | 220.9 | 304.9 | 202.7 | 375.4 | 280.0 | <0.0001 | *, ** |
| DHA intake (mg/day) | 500.8 | 338.2 | 547.8 | 332.8 | 658.7 | 448.3 | <0.0001 | *, ** |
| ARA intake (mg/day) | 158.3 | 59.2 | 165.8 | 60.1 | 178.1 | 73.1 | <0.001 | *, ** |
1 For continuous variables, one-way analysis of variance was used; for categorical variables, the χ2 test was used. 2 For continuous variables, the Tukey test was used for multiple comparisons (* Tertile 1 vs. Tertile 2 p < 0.05, ** Tertile 1 vs. Tertile 3 p < 0.05, *** Tertile 2 vs. Tertile 3 p < 0.05). DHA, docosahexaenoic acid; SD, standard deviation; METs, metabolic equivalents; EPA, eicosapentaenoic acid; ARA, arachidonic acid.