Table 3.
The association between levels of IL-6 and depressive symptoms after 5 years
| Inflammatory proteins | No. of cases | B (95 % CI) | P value |
|---|---|---|---|
| Log IL-6 (per 1 SD increment)α | |||
| Age, sex | 656 | 0.107 (1.32, 5.38) | 0.001 |
| Age, sex, BMI (kg/m2) | 652 | 0.109 (1.31, 5.46) | 0.001 |
| Age, sex, smoking status | 656 | 0.105 (1.24, 5.32) | 0.002 |
| Age, sex, physical illness | 656 | 0.106 (1.26, 5.34) | 0.002 |
| Age, sex, MMSE | 654 | 0.106 (1.27, 5.33) | 0.002 |
| Age, sex, acute inflammation | 656 | 0.088 (0.68, 4.83) | 0.009 |
| Fully adjusted* | 650 | 0.084 (0.48, 4.73) | 0.016 |
| Subgroups (age and sex adjusted) | |||
| Excluding those with acute inflammation | 627 | 0.089 (0.68, 4.91) | 0.010 |
| Excluding those with MMSE | 416 | 0.170 (2.99, 8.12) | 0.001 |
Individual contribution of each covariate
The category “depressive symptoms” includes all subjects who were screened positive. α = levels of IL-6 from measurements of 1997–1999: new onset of depressive symptoms at 5-year follow-up in participants with no depressive symptoms at baseline. Subjects on antidepressant medications were excluded from the analysis
IL-6 interleukin-6, SD standard deviation, B standardized beta, CI confidence interval, BMI body mass index, MMSE mini-mental state examination