TABLE 1.
Characteristics of 3088 participants at the 1992–1993 examination according to quartiles of plasma n−3 fatty acids1
| EPA+DHA |
ALA |
|||||||
| Quartile 1, low (n = 772) | Quartile 2 (n = 772) | Quartile 3 (n = 772) | Quartile 4, high (n = 772) | Quartile 1, low (n = 785) | Quartile 2 (n = 778) | Quartile 3 (n = 753) | Quartile 4, high (n = 772) | |
| Range (% of total plasma fatty acids) | ≤2.82 | >2.82–3.42 | >3.42–4.22 | >4.22 | ≤0.11 | >0.11–0.14 | >0.14–0.18 | >0.18 |
| Median (% of total plasma fatty acids) | 2.47 | 3.13 | 3.74 | 5.02 | 0.10 | 0.13 | 0.16 | 0.21 |
| Characteristic | ||||||||
| Age (y) | 74.9 ± 5.22 | 75.1 ± 5.3 | 75.0 ± 5.2 | 75.1 ± 5.33 | 74.9 ± 5.0 | 74.9 ± 5.3 | 75.1 ± 5.3 | 75.2 ± 5.33 |
| Men (%) | 44.0 | 38.6 | 35.4 | 37.7 | 46.6 | 39.9 | 37.1 | 32.0 |
| Black (%) | 3.4 | 7.6 | 14.4 | 17.9 | 13.1 | 11.3 | 12.0 | 6.9 |
| High school education or less (%) | 61.5 | 57.7 | 50.1 | 43.8 | 57.7 | 55.4 | 50.7 | 49.2 |
| Current smoker (%) | 13.6 | 9.7 | 7.8 | 6.2 | 10.6 | 12.3 | 6.5 | 7.8 |
| Alcoholic drinks/wk (%) | ||||||||
| None | 57.2 | 55.7 | 51.4 | 45.5 | 53.5 | 54.8 | 54.2 | 47.3 |
| <7–13 | 36.3 | 36.9 | 41.6 | 48.3 | 41.5 | 39.4 | 38.8 | 43.4 |
| ≥14 | 6.5 | 7.4 | 7.0 | 6.2 | 5.0 | 5.8 | 7.0 | 9.3 |
| Prevalent coronary disease (%) | 20.2 | 20.1 | 20.3 | 21.13 | 20.0 | 23.8 | 20.1 | 17.93 |
| Use of fish-oil supplements (%) | 1.3 | 1.9 | 5.2 | 6.7 | 3.4 | 3.7 | 4.7 | 3.4 |
| BMI (kg/m2) | 26.0 ± 4.4 | 26.5 ± 4.4 | 26.6 ± 4.7 | 26.3 ± 4.53 | 27.3 ± 4.8 | 26.5 ± 4.4 | 26.2 ± 4.5 | 25.4 ± 4.13 |
| Waist circumference (cm) | 95.7 ± 12.9 | 96.7 ± 12.5 | 96.8 ± 12.8 | 95.0 ± 13.03 | 99.0 ± 13.0 | 96.3 ± 12.3 | 95.6 ± 12.8 | 93.3 ± 12.4 |
| Physical activity (kcal/wk) | 960 (338, 2154)4 | 971 (368, 2010) | 836 (270, 1913) | 856 (305, 1905)3 | 915 (341, 2171) | 881 (270, 1890) | 840 (270, 1980) | 1016 (374, 2004)3 |
| Triglyceride (mg/dL) | 122 (93, 172) | 126 (91, 176) | 122 (91, 169) | 112 (81, 158) | 127 (94, 168) | 119 (91, 170) | 120 (89, 167) | 121 (83, 173)3 |
| LDL cholesterol (mg/dL) | 121.7 ± 34.2 | 119.6 ± 33.1 | 121.8 ± 33.1 | 120.3 ± 31.93 | 123.4 ± 32.5 | 122.2 ± 34.8 | 121.7 ± 31.6 | 116.0 ± 32.9 |
| Glucose (mg/dL) | 97.2 ± 9.9 | 97.4 ± 9.8 | 97.3 ± 9.6 | 97.0 ± 10.03 | 98.7 ± 10.1 | 97.6 ± 9.7 | 96.6 ± 9.3 | 96.0 ± 9.9 |
| Insulin (IU/mL) | 10.4 ± 6.8 | 11.6 ± 7.0 | 12.1 ± 16.1 | 10.4 ± 5.53 | 12.2 ± 8.2 | 11.7 ± 16.0 | 10.6 ± 5.9 | 9.9 ± 5.0 |
| HOMA-IR | 2.1 (1.5, 3.0) | 2.4 (1.6, 3.4) | 2.2 (1.6, 3.3) | 2.2 (1.6, 3.1)3 | 2.4 (1.7, 3.6) | 2.3 (1.6, 3.2) | 2.1 (1.6, 3.1) | 2.0 (1.4, 2.9) |
| Dietary EPA+DHA (g/d)5 | 0.17 (0.10, 0.30) | 0.25 (0.16, 0.46) | 0.36 (0.22, 0.57) | 0.56 (0.33, 0.76) | 0.27 (0.15, 0.53) | 0.29 (0.16, 0.55) | 0.29 (0.17, 0.55) | 0.35 (0.19, 0.60) |
| Dietary ALA (g/d)5 | 1.35 (1.11, 1.64) | 1.33 (1.10, 1.61) | 1.37 (1.13, 1.62) | 1.35 (1.09, 1.61)3 | 1.27 (1.06, 1.52) | 1.33 (1.08, 1.62) | 1.38 (1.13, 1.65) | 1.41 (1.16, 1.66) |
| Dietary linoleic acid (g/d)5 | 11.7 (9.5, 14.3) | 11.6 (9.6, 14.3) | 11.5 (9.5, 13.9) | 11.4 (8.9, 13.6) | 11.2 (9.3, 13.7) | 11.5 (9.3, 13.9) | 11.8 (9.4, 14.1) | 11.8 (9.7, 14.0) |
| Fish servings/wk5 | 0.8 (0.5, 1.5) | 1.2 (0.7, 1.9) | 1.6 (0.9, 2.3) | 2.0 (1.5, 3.0) | 1.3 (0.7, 2.0) | 1.3 (0.7, 2.0) | 1.5 (0.8, 2.2) | 1.5 (0.8, 2.3) |
1
EPA+DHA, eicosapentaenoic acid and docosahexaenoic acid; ALA, α-linolenic acid; HOMA-IR, homeostatic model assessment of insulin resistance. Linear and logistic regression was used to assess linear trends of characteristics across quartiles of fatty acids and were significant (P < 0.05) unless otherwise noted.
2
Mean ± SD (all such values).
3
Linear test for trend, P > 0.05.
4
Median; interquartile range in parentheses (all such values).
5
Cumulative average of energy-corrected values from food-frequency questionnaires administered in 1989–1990 and 1995–1996 in participants enrolled in 1989–1990 only (n = 2831).