Table 3.
Association between plasma vitamin C quartile and SF-36 domain (physical functions and vitality).
| Vitamin Quartile | Unadjusted | Model A | Model B | Model C | Model D | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Odds ratio | 95% CI | p-value | Odds ratio | 95% CI | p-value | Odds ratio | 95% CI | p-value | Odds ratio | 95% CI | p-value | Odds ratio | 95% CI | p-value | ||
| Physical function* | 1 (Lowest) | 2.03 | (1.75-2.35) | <0.01 | 2.17 | (1.85–2.54) | <0.01 | 1.75 | (1.48–2.06) | <0.01 | 1.56 | (1.32–1.84) | <0.01 | 1.43 | (1.21–1.70) | <0.01 |
| 2 | 1.28 | (1.10–1.51) | <0.01 | 1.42 | (1.21–1.68) | <0.01 | 1.3 | (1.09–1.54) | <0.01 | 1.16 | (0.97–1.38) | 0.1 | 1.11 | (0.93–1.32) | 0.24 | |
| 3 | 0.91 | (0.77–1.07) | 0.24 | 0.99 | (0.84–1.17) | 0.92 | 0.96 | (0.80–1.14) | 0.61 | 0.89 | (0.75–1.06) | 0.2 | 0.88 | (0.73–1.05) | 0.15 | |
| 4 (Highest) | 1 | 1 | 1 | 1 | 1 | |||||||||||
| Role physical health** | 1 (Lowest) | 1.6 | (1.41–1.81) | <0.01 | 1.63 | (1.43–1.87) | <0.01 | 1.41 | (1.23–1.62) | <0.01 | 1.33 | (1.16–1.53) | <0.01 | 1.26 | (1.10–1.45) | 0.001 |
| 2 | 1.16 | (1.02–1.32) | 0.02 | 1.23 | (1.07–1.41) | <0.01 | 1.15 | (1.00–1.32) | 0.05 | 1.09 | (0.95–1.25) | 0.23 | 1.06 | (0.92–1.22) | 0.42 | |
| 3 | 0.98 | (0.86–1.12) | 0.74 | 1.04 | (0.91–1.18) | 0.60 | 1 | (0.88–1.15) | 0.95 | 0.98 | (0.85–1.12) | 0.72 | 0.97 | (0.84–1.11) | 0.62 | |
| 4 (Highest) | 1 | 1 | 1 | 1 | 1 | |||||||||||
| Bodily Pain* | 1 (Lowest) | 1.68 | (1.42–2.00) | <0.01 | 1.83 | (1.53–2.18) | <0.01 | 1.49 | (1.24–1.79) | 0.001 | 1.37 | (1.13–1.65) | <0.01 | 1.29 | (1.07–1.56) | 0.01 |
| 2 | 1.19 | (0.99–1.42) | 0.06 | 1.29 | (1.08–1.55) | 0.01 | 1.19 | (0.99–1.44) | 0.07 | 1.1 | (0.91–1.33) | 0.34 | 1.07 | (0.89–1.30) | 0.47 | |
| 3 | 1 | (0.84–1.20) | 0.98 | 1.06 | (0.88–1.27) | 0.54 | 0.99 | (0.82–1.20) | 0.94 | 0.95 | (0.79–1.15) | 0.59 | 0.95 | (0.78–1.14) | 0.57 | |
| 4 (Highest) | 1 | 1 | 1 | 1 | 1 | |||||||||||
| Vitality* | 1 (Lowest) | 1.35 | (1.17–1.57) | <0.01 | 1.6 | (1.38–1.87) | <0.01 | 1.34 | (1.14–1.58) | <0.01 | 1.29 | (1.10–1.52) | <0.01 | 1.23 | (1.04–1.45) | 0.01 |
| 2 | 1.12 | (0.96–1.30) | 0.15 | 1.26 | (1.08–1.47) | <0.01 | 1.16 | (0.99–1.36) | 0.07 | 1.12 | (0.95–1.32) | 0.17 | 1.1 | (0.94–1.30) | 0.23 | |
| 3 | 0.98 | (0.85–1.15) | 0.84 | 1.04 | (0.90–1.22) | 0.59 | 1.03 | (0.88–1.20) | 0.75 | 1.01 | (0.86–1.18) | 0.92 | 1 | (0.85–1.17) | 0.96 | |
| 4 (Highest) | 1 | 1 | 1 | 1 | 1 | |||||||||||
| General health* | 1 (Lowest) | 2.01 | (1.72–2.35) | <0.01 | 1.92 | (1.64–2.26) | <0.01 | 1.56 | (1.32–1.84) | <0.01 | 1.48 | (1.25–1.75) | <0.01 | 1.4 | (1.18–1.66) | <0.01 |
| 2 | 1.38 | (1.17–1.62) | <0.01 | 1.36 | (1.15–1.60) | <0.01 | 1.23 | (1.04–1.46) | 0.02 | 1.17 | (0.99–1.39) | 0.07 | 1.14 | (0.96–1.36) | 0.13 | |
| 3 | 1 | (0.84–1.19) | 0.99 | 1 | (0.84–1.19) | 0.99 | 0.95 | (0.79–1.13) | 0.54 | 0.92 | (0.77–1.10) | 0.37 | 0.91 | (0.76–1.09) | 0.31 | |
| 4 (Highest) | 1 | 1 | 1 | 1 | 1 | |||||||||||
* Outcome defined as bottom decile vs. all other deciles; ** Outcome defined as the bottom quintile vs. rest; Model A: Basic model + age and sex. Model B: model B + smoking, physical activity and alcohol intake. Model C: model B + BMI. Model D: model C + education status, Townsend index and previous medical history (cancer, diabetes, cerebrovascular incident, myocardial infarction, asthma).