Table 4.
Progression of Common Carotid Intima-media Thickness (IMT, µm/year) by Quintile of Intake of Vitamin C from the Diet. Data are from the Los Angeles Atherosclerosis Study, 1994-1999 (n=500)
| Carotid Intima-Media Thickness (IMT) | Quintiles of Vitamin C Intake from Food | P-value† | ||||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | ||
| (+) Dietary Vitamin C Intake | Difference from First Quintile | |||||
| Mean (µm/year) | 8.5 | 2.2 | 3.7 | 2.4 | -1.1 | |
| Standard Error | 1.7 | |||||
| Model 1* | 0.7 | 2.5 | 0.2 | -4.1 | 0.11 | |
| Standard Error | 2.3 | 2.3 | 2.4 | 2.5 | ||
| P-value (vs. First Quintile) | 0.76 | 0.28 | 0.93 | 0.10 | ||
| Model 2 | 1.1 | 4.0 | 1.4 | -2.1 | 0.5 | |
| Standard Error | 2.3 | 2.3 | 2.4 | 2.5 | ||
| P-value | 0.63 | 0.08 | 0.56 | 0.41 | ||
| Model 3 | 1.2 | 4.6 | 1.6 | -1.8 | 0.57 | |
| Standard Error | 2.3 | 2.3 | 2.3 | 2.5 | ||
| P-value | 0.6 | 0.04 | 0.5 | 0.47 | ||
*
For definitions of Models 1, 2 and 3, see notes to Table 2.
†
Rate of IMT progression was reduced in the top quintile of vitamin C intake relative to the other four quintiles (p=0.008, 0.05 and 0.04 in Models 1, 2 and 3, respectively).