TABLE 2.
Bivariate and minimally adjusted associations between plasma fatty acids and actigraphy-assessed weekday sleep characteristics in a sample of 405 Mexican youth1
| n | Weekday duration,2 min | Weekday midpoint,3 decimal h | Fragmentation index,4 % | ||||
|---|---|---|---|---|---|---|---|
| DHA, % of total FA | |||||||
| Q1 (median = 0.81) | 102 | 498 (464, 541)5 | 10 (−11, 31)6 | 3.7 (2.7, 4.9)5 | 0.33 (−0.04, 0.70)6 | 11.6 (9.8, 13.6)5 | 0.8 (−0.2, 1.9)6 |
| Q2 (median = 1.05) | 101 | 515 (468, 581) | 19 (−2, 40) | 4.6 (3.1, 5.2) | 0.82 (0.46, 1.19) | 11.4 (9.2, 14.8) | 0.8 (−0.3, 1.8) |
| Q3 (median = 1.25) | 101 | 499 (447, 548) | −2 (−24, 19) | 3.3 (2.6, 4.6) | 0.07 (−0.30, 0.45) | 11.8 (8.9, 14.5) | 0.5 (−0.5, 1.6) |
| Q4 (median = 1.61) | 101 | 501 (451, 551) | Reference | 3.4 (2.5, 4.3) | Reference | 10.9 (8.6, 13.7) | Reference |
| P trend7 | 0.12 | 0.003 | 0.11 | ||||
| AA, % of total FA | |||||||
| Q1 (median = 4.6) | 95 | 513 (467, 551) | Reference | 4.0 (2.9, 5.1) | Reference | 11.5 (9.4, 14.0) | Reference |
| Q2 (median = 5.8) | 109 | 500 (460, 566) | −7 (−28, 13) | 3.5 (2.7, 4.9) | −0.30 (−0.66, 0.07) | 11.4 (9.3, 13.7) | −0.1 (−1.1, 0.9) |
| Q3 (median = 6.7) | 104 | 509 (470, 563) | −2 (−23, 19) | 3.7 (2.8, 4.7) | −0.22 (−0.59, 0.15) | 11.8 (9.6, 14.6) | 0.3 (−0.7, 1.4) |
| Q4 (median = 7.8) | 97 | 498 (438, 535) | −20 (−41, 0) | 3.3 (2.5, 4.7) | −0.51 (−0.88, −0.14) | 10.9 (8.6, 14.7) | −0.2 (−1.3, 0.8) |
| P trend | 0.09 | 0.01 | 0.83 | ||||
| DHA:AA ratio | |||||||
| Q1 (median = 0.14) | 102 | 500 (456, 551) | −1 (−22, 21) | 3.7 (2.8, 4.9) | 0.22 (−0.16, 0.59) | 12.2 (9.8, 15.2) | 0.6 (−0.4, 1.7) |
| Q2 (median = 0.17) | 101 | 495 (446, 540) | −16 (−36, 5) | 4.0 (2.6, 5.1) | 0.21 (−0.16, 0.59) | 10.9 (8.8, 13.5) | −0.4 (−1.4, 0.6) |
| Q3 (median = 0.20) | 101 | 511 (452, 557) | −6 (−27, 15) | 3.8 (2.7, 4.9) | 0.21 (−0.17, 0.58) | 11.5 (8.5, 14.0) | −0.1 (−1.2, 0.9) |
| Q4 (median = 0.25) | 101 | 516 (467, 574) | Reference | 3.4 (2.6, 4.7) | Reference | 11.5 (9.4, 14.1) | Reference |
| P trend | 0.77 | 0.28 | 0.29 | ||||
AA, arachidonic acid; FA, fatty acid; Q, quartile.
Sleep duration averaged over the weekday nights (Sunday through Thursday).
Sleep midpoint (median of sleep onset and wake time) averaged over the weekday nights.
Calculated as the percentage of 1-min periods of sleep out of total number of sleep bouts of any length, averaged over the 7-d wear time.
Values are median (interquartile range).
Values are adjusted differences (95% CIs); from linear regression models with sleep characteristic as the dependent variable, indicator variables for quartiles of plasma fatty acid as the independent predictor; and sex, continuous age, and indicator variables for categories of maternal education and BMI-for-age z-scores as potential confounders. Plasma DHA and AA were run in separate models.
Values of P for trends are from Wald tests in adjusted linear regression models with a continuous variable representing ordinal categories of plasma fatty acid quartiles.