TABLE 1.
Plasma fatty acid concentrations of 405 youth aged 9–17 y from Mexico City, according to sociodemographic and lifestyle characteristics1
| Sociodemographic and lifestyle characteristics | n | DHA, % of total fatty acid | AA, % of total fatty acid | DHA:AA ratio |
|---|---|---|---|---|
| Sex | ||||
| Male | 195 | 1.11 (0.89, 1.30) | 6.15 (5.21, 7.25) | 0.18 (0.15, 0.20) |
| Female | 210 | 1.20 (0.99, 1.51) | 6.25 (5.30, 7.16) | 0.20 (0.16, 0.24) |
| P value2 | 0.0004 | 0.96 | 0.0001 | |
| Age group, y | ||||
| 9.5 to <12 | 83 | 1.17 (0.93, 1.40) | 6.41 (5.23, 7.08) | 0.19 (0.16, 0.22) |
| 12 to <14 | 123 | 1.15 (0.93, 1.44) | 6.04 (5.20, 7.06) | 0.19 (0.17, 0.22) |
| 14 to <16 | 82 | 1.10 (0.98, 1.39) | 6.17 (5.47, 7.02) | 0.18 (0.16, 0.22) |
| 16 to <18 | 117 | 1.17 (0.94, 1.36) | 6.43 (5.21, 7.41) | 0.19 (0.15, 0.22) |
| P trend | 0.97 | 0.51 | 0.84 | |
| BMI z-score | ||||
| <0 | 43 | 1.17 (1.01, 1.48) | 6.72 (5.42, 7.49) | 0.18 (0.16, 0.22) |
| 0 to <1 | 102 | 1.16 (0.95, 1.48) | 6.35 (5.48, 7.29) | 0.19 (0.16, 0.22) |
| 1 to <2 | 102 | 1.18 (0.98, 1.37) | 6.12 (5.23, 7.25) | 0.19 (0.16, 0.23) |
| ≥2 | 156 | 1.10 (0.89, 1.34) | 5.91 (4.93, 7.03) | 0.19 (0.16, 0.22) |
| P trend | 0.02 | 0.01 | 0.36 | |
| Maternal education, y | ||||
| ≤9 (secondary or primary) | 155 | 1.13 (0.92, 1.33) | 6.21 (5.27, 7.25) | 0.18 (0.16, 0.21) |
| 10 to <12 (some high school) | 51 | 1.22 (0.92, 1.47) | 6.10 (5.42, 7.09) | 0.20 (0.17, 0.23) |
| 12 (completed high school) | 139 | 1.16 (0.97, 1.49) | 6.44 (5.44, 7.38) | 0.19 (0.16, 0.22) |
| >12 | 56 | 1.10 (0.93, 1.43) | 5.64 (4.94, 6.91) | 0.19 (0.17, 0.23) |
| P trend | 0.18 | 0.82 | 0.66 | |
| Physical activity quartiles, h/wk | ||||
| Q1, 0 to <5.8 | 110 | 1.16 (0.96, 1.46) | 6.11 (5.37, 7.02) | 0.20 (0.16, 0.23) |
| Q2, 5.8 to <9.3 | 100 | 1.18 (0.94, 1.42) | 6.14 (5.26, 7.29) | 0.19 (0.16, 0.23) |
| Q3, 9.3 to <14.3 | 100 | 1.13 (0.98, 1.36) | 6.33 (5.25, 7.31) | 0.19 (0.15, 0.23) |
| Q4, 14.3 to 29 | 95 | 1.13 (0.89, 1.36) | 6.37 (5.04, 7.25) | 0.18 (0.16, 0.21) |
| P trend | 0.30 | 0.55 | 0.78 | |
| Screen time quartiles, h/wk | ||||
| Q1, 1 to <23 | 104 | 1.14 (0.92, 1.48) | 6.25 (5.21, 7.07) | 0.19 (0.16, 0.23) |
| Q2, 23 to <33 | 107 | 1.19 (0.97, 1.40) | 6.40 (5.48, 7.38) | 0.19 (0.16, 0.22) |
| Q3, 33 to <48.5 | 96 | 1.17 (0.88, 1.41) | 6.15 (5.21, 7.08) | 0.19 (0.16, 0.22) |
| Q4, 48.5 to 116 | 98 | 1.10 (0.94, 1.36) | 5.93 (5.19, 7.19) | 0.18 (0.15, 0.22) |
| P trend | 0.22 | 0.57 | 0.92 | |
| Ever smoked cigarettes | ||||
| No | 317 | 1.16 (0.94, 1.43) | 6.19 (5.23, 7.17) | 0.19 (0.16, 0.22) |
| Yes | 86 | 1.10 (0.96, 1.26) | 6.20 (5.25, 7.25) | 0.19 (0.16, 0.22) |
| P value | 0.45 | 0.96 | 0.52 | |
| Caffeine intake quartiles, mg/d | ||||
| Q1, 0 to <0.10 | 102 | 1.14 (0.91, 1.36) | 6.42 (5.25, 7.18) | 0.18 (0.16, 0.21) |
| Q2, 0.10 to <0.63 | 104 | 1.19 (1.00, 1.44) | 6.02 (5.31, 7.29) | 0.19 (0.16, 0.23) |
| Q3, 0.63 to <33 | 98 | 1.12 (0.93, 1.41) | 6.10 (5.21, 7.06) | 0.19 (0.16, 0.22) |
| Q4, 33 to 681 | 101 | 1.14 (0.94, 1.42) | 6.22 (5.11, 7.25) | 0.19 (0.16, 0.23) |
| P trend | 0.55 | 0.89 | 0.91 | |
| Canned tuna/sardine intake, g/d | ||||
| 0 | 236 | 1.09 (0.89, 1.32) | 6.22 (5.35, 7.18) | 0.18 (0.15, 0.20) |
| >0 to <14 | 66 | 1.19 (1.04, 1.52) | 6.11 (5.04, 6.98) | 0.21 (0.18, 0.24) |
| 14 to 251 | 103 | 1.24 (1.04, 1.54) | 6.25 (4.99, 7.26) | 0.21 (0.17, 0.25) |
| P trend | <0.0001 | 0.57 | <0.0001 | |
1
Values are median (interquartile range). AA, arachidonic acid.
2
For dichotomous characteristics, P values are from Wilcoxon tests. For ordinal characteristics, values of P for trends are from linear regression models with plasma fatty acid as the dependent variable and a continuous variable representing ordinal categories of the sociodemographic or lifestyle predictor as the independent variable.