Table 4.
Depressive symptoms according to quintile of serum fatty acid concentration (Odds ratios and 95 % confidence intervals)
| Q1 (low) | Q2 | Q3 | Q4 | Q5 (high) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| OR | 95 % CI | OR | 95 % CI | OR | 95 % CI | OR | 95 % CI | OR | 95 % CI | P for trend † | |
| n-3 PUFA | |||||||||||
| DHA | |||||||||||
| Median of serum fatty acid concentration (μg/ml) | 108·8 | 138·5 | 165·6 | 195·0 | 244·9 | ||||||
| Range of serum fatty acid concentration (μg/ml) | 25·8–125·0 | 125·2–153·2 | 153·3–178·4 | 178·5–214·2 | 214·4–609·3 | ||||||
| Number with/without depressive symptoms‡ | 56/368 | 64/361 | 52/372 | 55/368 | 39/388 | ||||||
| Crude | 1·00 | Ref. | 1·17 | 0·79, 1·72 | 0·92 | 0·61, 1·38 | 0·98 | 0·66, 1·46 | 0·66 | 0·43, 1·02 | 0·039* |
| Model I: multivariate-adjusted§ | 1·00 | Ref. | 1·10 | 0·74, 1·62 | 0·84 | 0·55, 1·27 | 0·87 | 0·58, 1·31 | 0·57* | 0·36, 0·90 | 0·008** |
| Model II: multivariate-adjusted|| | 1·00 | Ref. | 1·09 | 0·74, 1·63 | 0·80 | 0·53, 1·23 | 0·86 | 0·56, 1·31 | 0·58* | 0·37, 0·92 | 0·011* |
| EPA | |||||||||||
| Median of serum fatty acid concentration (μg/ml) | 31·9 | 51·5 | 69·1 | 92·2 | 131·2 | ||||||
| Range of serum fatty acid concentration (μg/ml) | 10·1–41·6 | 41·8–59·9 | 60·0–79·6 | 79·7–107·1 | 107·3–333·1 | ||||||
| Number with/without depressive symptoms‡ | 66/354 | 54/375 | 57/367 | 41/381 | 48/380 | ||||||
| Crude | 1·00 | Ref. | 0·77 | 0·52, 1·14 | 0·83 | 0·57, 1·22 | 0·58* | 0·38, 0·88 | 0·68 | 0·46, 1·01 | 0·021* |
| Model I: multivariate-adjusted§ | 1·00 | Ref. | 0·74 | 0·50, 1·09 | 0·78 | 0·53, 1·15 | 0·52* | 0·34, 0·80 | 0·61 | 0·40, 0·93* | 0·006** |
| Model II: multivariate-adjusted|| | 1·00 | Ref. | 0·77 | 0·52, 1·15 | 0·77 | 0·52, 1·15 | 0·55* | 0·35, 0·85 | 0·64 | 0·42, 0·98* | 0·013* |
| ALA | |||||||||||
| Median of serum fatty acid concentration (μg/ml) | 15·7 | 20·2 | 24·8 | 30·2 | 42·4 | ||||||
| Range of serum fatty acid concentration (μg/ml) | 7·7–18·0 | 18·1–22·3 | 22·4–27·2 | 27·3–34·4 | 34·5–673·6 | ||||||
| Number with/without depressive symptoms‡ | 58/359 | 55/373 | 61/364 | 45/383 | 47/378 | ||||||
| Crude | 1·00 | Ref. | 0·91 | 0·61, 1·36 | 1·04 | 0·70, 1·53 | 0·73 | 0·48, 1·10 | 0·77 | 0·51, 1·16 | 0·111 |
| Model I: multivariate-adjusted§ | 1·00 | Ref. | 0·88 | 0·59, 1·31 | 0·99 | 0·67, 1·46 | 0·67 | 0·44, 1·02 | 0·74 | 0·49, 1·12 | 0·065 |
| Model II: multivariate-adjusted|| | 1·00 | Ref. | 0·92 | 0·61, 1·38 | 1·00 | 0·67, 1·50 | 0·70 | 0·45, 1·08 | 0·73 | 0·48, 1·13 | 0·073 |
| n-6 PUFA | |||||||||||
| ARA | |||||||||||
| Median of serum fatty acid concentration (μg/ml) | 128·4 | 152·6 | 170·3 | 191·8 | 225·4 | ||||||
| Range of serum fatty acid concentration (μg/ml) | 66·6–142·3 | 142·4–161·2 | 161·3–179·7 | 179·8–205·6 | 205·7–411·0 | ||||||
| Number with/without depressive symptoms‡ | 55/369 | 48/376 | 56/369 | 55/370 | 52/373 | ||||||
| Crude | 1·00 | Ref. | 0·86 | 0·57, 1·29 | 1·02 | 0·68, 1·52 | 1·00 | 0·67, 1·49 | 0·94 | 0·62, 1·40 | 0·968 |
| Model I: multivariate-adjusted§ | 1·00 | Ref. | 0·84 | 0·56, 1·27 | 1·00 | 0·67, 1·50 | 0·96 | 0·64, 1·44 | 0·94 | 0·63, 1·42 | 0·975 |
| Model II: multivariate-adjusted|| | 1·00 | Ref. | 0·82 | 0·54, 1·25 | 1·00 | 0·66, 1·50 | 0·95 | 0·63, 1·44 | 0·93 | 0·61, 1·41 | 0·987 |
| LA | |||||||||||
| Median of serum fatty acid concentration (μg/ml) | 698·3 | 809·2 | 899·2 | 944·9 | 1151·3 | ||||||
| Range of serum fatty acid concentration (μg/ml) | 409·8–759·2 | 759·5–856·2 | 856·4–942·5 | 942·7–1053·1 | 1053·3–2839·5 | ||||||
| Number with/without depressive symptoms‡ | 53/371 | 57/368 | 53/371 | 53/372 | 50/375 | ||||||
| Crude | 1·00 | Ref. | 1·08 | 0·73, 1·62 | 1·00 | 0·67, 1·50 | 1·00 | 0·66, 1·50 | 0·93 | 0·62, 1·41 | 0·636 |
| Model I: multivariate-adjusted§ | 1·00 | Ref. | 1·11 | 0·74, 1·66 | 0·99 | 0·66, 1·49 | 0·99 | 0·66, 1·50 | 0·96 | 0·63, 1·46 | 0·691 |
| Model II: multivariate-adjusted|| | 1·00 | Ref. | 1·10 | 0·73, 1·65 | 0·99 | 0·65, 1·51 | 1·00 | 0·66, 1·52 | 0·98 | 0·64, 1·50 | 0·783 |
Q, quintiles; Ref., referent value; ALA, α-linolenic acid; ARA, arachidonic acid; LA, linoleic acid.
* P<0·05, ** P<0·01.
†
P for trend estimated by treating quintiles as ordinal variables for serum fatty acid concentration.
‡
A person with total score ≥16 using the Center for Epidemiologic Studies Depression Scale is supposed to have a significant depressive tendency.
§
Model I: adjusted for sex and age.
||
Model II: adjusted for sex, age, BMI, education level, marital status, smoking status, alcohol consumption, physical activity, employment status, and medical history.