. Author manuscript; available in PMC: 2016 Oct 1.

Published in final edited form as: Brain Behav Immun. 2015 Jun 1;49:130–139. doi: 10.1016/j.bbi.2015.05.008

Table 1.

Bivariate associations between study variables and depression as a dichotomous variable (≥48 indicates a mean item score ≥3, i.e. “often” experiencing symptom).

Immune activation biomarkers	≥48 (High-scorers, 10%^a)	<48 (Lower-scorers, 90%)	N
Cytokine or CRP concentration
TNF-α (pg/mL) (median)	10.95^***	8.06	634
IL-1β (pg/mL) (median)	0.07^{^}	0.06	636
IL-6 (pg/mL) (median)	0.82^**	0.52	649
CRP (mg/L) (median)	5.49^**	1.80	496
Cytokine response to ex vivo antigen stimulation
TNF-α (pg/mL)
LPS-stimulated (median)	143	149	117
PHA-stimulated (median)	62^{^}	38	121
IL-1β (pg/mL)
LPS-stimulated (median)	540	468	119
PHA-stimulated (median)	239^*	98	123
IL-6 (pg/mL)
LPS-stimulated (median)	3,719^*	2,589	118
PHA-stimulated (median)	3,461^*	2,053	124
Controls
Age (years) (mean±SD)	55.4^{^} ± 11.9	53.0 ± 10.8	649
% female	72^***	46	649
BMI (kg/m²) (mean±SD)	23.5^{^} ± 3.9	24.1 ± 3.3	649

^***

p≤0.001

^**

p≤0.01

p≤0.05

^{^}

p≤0.1 (compared to lower-scorers; Mann-Whitney U or χ² test)

Risk set includes interviewees that provided a morning fasting blood sample (n=649)