Table 3.
Relative Biomarker Concentrations
| Geometric Mean of Ratio (95% CI) | |||
|---|---|---|---|
| EC/Abstinence | Smoking/Abstinence | Smoking/EC | |
| Urine biomarkers | |||
| Epinephrine (µg/24 h) | 1.15 (0.94–1.40) | 1.15 (0.97–1.36) | 1.00 (0.87–1.15) |
| Epinephrine (ng/mL) | 1.12 (0.96–1.31) | 1.04 (0.90–1.20) | 0.92 (0.80–1.07) |
| Epinephrine (ng/mg Cr) | 1.18 (0.98–1.40) | 1.22 (1.03–1.45)* | 1.04 (0.90–1.20) |
| Norepinephrine (µg/24 h) | 0.95 (0.85–1.06) | 0.97 (0.88–1.07) | 1.02 (0.90–1.15) |
| Norepinephrine (ng/mL) | 0.94 (0.81–1.08) | 0.87 (0.75–1.01) | 0.93 (0.81–1.06) |
| Norepinephrine (ng/mg Cr) | 1.00 (0.92–1.08) | 1.03 (0.93–1.14) | 1.03 (0.93–1.13) |
| Dopamine (µg/24 h) | 0.95 (0.87–1.04) | 0.95 (0.86–1.04) | 1.00 (0.90–1.11) |
| Dopamine (ng/mL) | 0.94 (0.81–1.08) | 0.86 (0.74–0.99) | 0.91 (0.80–1.04) |
| Dopamine (ng/mg Cr) | 1.00 (0.93–1.07) | 1.01 (0.93–1.09) | 1.01 (0.93–1.10) |
| 8‐Isoprostane (ng/24 h) | 1.09 (0.81–1.48) | 1.23 (0.94–1.63) | 1.13 (0.88–1.45) |
| 8‐Isoprostane (ng/mL) | 1.18 (0.88–1.57) | 1.19 (0.89–1.61) | 1.02 (0.83–1.24) |
| 8‐Isoprostane (ng/mg cr) | 1.23 (0.92–1.64) | 1.42 (1.07–1.90)* | 1.16 (0.94–1.42) |
| 11‐dhTxB2 (ng/24 h) | 1.25 (0.68–2.30) | 1.49 (0.86–2.61) | 1.19 (0.92–1.54) |
| 11‐dhTxB2 (ng/mL) | 1.35 (0.76–2.39) | 1.45 (0.85–2.45) | 1.07 (0.86–1.34) |
| 11‐dhTxB2 (ng/mg Cr) | 1.40 (0.77–2.59) | 1.72 (0.98–3.03) | 1.22 (0.97–1.54) |
| Plasma biomarkers | |||
| Interleukin‐6 (pg/mL) | 1.84 (1.20–2.82)† | 2.26 (1.37–3.74)† | 0.89 (0.51–1.53) |
| Interleukin‐8 (pg/mL) | 1.36 (1.12–1.63)† | 1.43 (1.21–1.69)† | 1.06 (0.86–1.30) |
Geometric means of relative biomarker concentrations reflect pairwise‐differences following mixed model analysis with random effects for repeated measures within subject and fixed effects for treatment order. Study arm effects: * P<0.05, † P<0.01. 11‐dhTxB2 indicates 11‐dehydro‐thromboxane B2; Cr, creatinine; and EC, electronic cigarette.