Intention-to-treat analysis of circulating oxidative stress biomarker levels for exercisers and controls in the ALPHA Trial
| Baseline | Six months | Twelve months | Per cent change from baseline to 12 months | TER of exercise/control (95% CI)† | Between-group p value | ||||
|---|---|---|---|---|---|---|---|---|---|
| Geometric mean (95% CI)* | n | Geometric mean (95% CI)* | n | Geometric mean (95% CI)* | n | ||||
| SOD (μmol/L/min) | |||||||||
| Exercisers | 12.4 (12.1 to 12.8) | 155 | 12.4 (11.9 to 12.8) | 154 | 12.2 (11.9 to 12.6) | 154 | −1.6 | 0.98 (0.95 to 1.01) | 0.26 |
| Controls | 12.2 (11.9 to 12.6) | 159 | 12.4 (12.0 to 12.7) | 154 | 12.6 (12.2 to 13.0) | 155 | 2.8 | ||
| CAT (μmol/L/min) | |||||||||
| Exercisers | 20.6 (18.8 to 22.6) | 156 | 21.5 (19.6 to 23.6) | 154 | 21.3 (19.4 to 23.5) | 154 | 3.4 | 1.03 (0.96 to 1.10) | 0.47 |
| Controls | 19.1 (17.5 to 20.9) | 159 | 19.5 (17.8 to 21.3) | 154 | 19.5 (17.8 to 21.5) | 156 | 2.2 | ||
| 8-iso-PGF2α (ng/L) | |||||||||
| Exercisers | 228 (213 to 245) | 149 | 219 (205 to 235) | 150 | 209 (190 to 231) | 149 | −8.3 | 0.97 (0.89 to 1.05) | 0.46 |
| Controls | 230 (216 to 245) | 154 | 218 (202 to 237) | 146 | 223 (209 to 239) | 147 | −3.0 | ||
| 8-OHdG (ng/L) | |||||||||
| Exercisers | 7.1 (6.8 to 7.3) | 156 | 7.1 (6.9 to 7.4) | 154 | 7.2 (7.0 to 7.5) | 154 | 2.7 | 0.99 (0.96 to 1.02) | 0.60 |
| Controls | 7.1 (6.8 to 7.4) | 156 | 7.2 (6.9 to 7.5) | 152 | 7.2 (7.0 to 7.5) | 155 | 1.9 | ||
*Blood samples from n=159 participants in the control group and n=156 participants in the exercise group were obtained. A further n=1, 12 and 3 participants were removed from the SOD, 8-iso-PGF2α and 8-OHdG analyses, respectively, as they were outliers or below the limit of detection.
†The TER was calculated based on a linear mixed model for each biomarker, adjusted for time and baseline value of the biomarker. The TER represents the adjusted ratio of geometric means for the exercise group over the control group. A TER of <1.0 indicates lower oxidative stress biomarker or antioxidant activity levels in the exercise group relative to the control group at 6 and 12 months; a TER >1.0 indicates higher oxidative stress biomarker or antioxidant activity levels in the exercise group; and a ratio of 1.0 indicates no difference between groups.
8-OHdg, 8-hydroxy-2′-deoxyguanosine; CAT, catalase; 8-iso-PGF2α, 8-isoprostaglandin F2α; SOD, superoxide dismutase; TER, treatment effect ratio.