Table 2.
Associations of Plasma Tryptophan, Kynurenic Acid, and Kynurenic Acid-to-Tryptophan Ratio With Risk of Carotid Artery Plaque
| All | Women | Men | P for Interaction | HIV+ | HIV− | P for Interaction | ||
|---|---|---|---|---|---|---|---|---|
| RR (95% CI) | P Value | RR (95% CI) | RR (95% CI) | RR (95% CI) | RR (95% CI) | |||
| Number of participants | 112/737 | 45/398 | 67/339 | 90/520 | 22/217 | |||
| Tryptophan | ||||||||
| Model 1a | 0.71 (0.62, 0.84) | <.001 | 0.66 (0.54, 0.80) | 0.78 (0.63, 0.96) | .27 | 0.76 (0.63, 0.91) | 0.77 (0.51, 1.14) | .99 |
| Model 2b | 0.76 (0.65, 0.89) | <.001 | 0.69 (0.56, 0.84) | 0.84 (0.67, 1.04) | .20 | 0.76 (0.64, 0.90) | 0.77 (0.51, 1.14) | .96 |
| Model 3c | 0.82 (0.69, 0.97) | .02 | 0.77 (0.62, 0.96) | 0.87 (0.70, 1.08) | .45 | 0.84 (0.70, 1.01) | 0.67 (0.44, 1.02) | .38 |
| Model 4d | 0.81 (0.67, 0.99) | .04 | 0.78 (0.60, 1.00) | 0.85 (0.67, 1.09) | .56 | 0.82 (0.67, 1.02) | 0.75 (0.47, 1.19) | .72 |
| Kynurenic acid | ||||||||
| Model 1a | 1.34 (1.06, 1.69) | .02 | 1.49 (1.12, 1.98) | 1.13 (0.81, 1.59) | .25 | 1.32 (1.03, 1.68) | 1.42 (0.93, 2.17) | .76 |
| Model 2b | 1.33 (1.08, 1.64) | .007 | 1.40 (1.08, 1.81) | 1.23 (0.88, 1.70) | .54 | 1.31 (1.05, 1.65) | 1.42 (0.93, 2.17) | .70 |
| Model 3c | 1.27 (1.03, 1.55) | .02 | 1.32 (1.03, 1.68) | 1.18 (0.85, 1.64) | .60 | 1.27 (1.03, 1.58) | 1.23 (0.79, 1.90) | .86 |
| Model 4d | 1.29 (1.02, 1.63) | .03 | 1.37 (1.02, 1.83) | 1.16 (0.82, 1.66) | .48 | 1.32 (1.03, 1.70) | 1.13 (0.71, 1.79) | .54 |
| Kynurenic acid-to-tryptophan ratio | ||||||||
| Model 1a | 1.47 (1.26, 1.73) | <.001 | 1.54 (1.30, 1.83) | 1.33 (0.97, 1.82) | .42 | 1.40 (1.18, 1.67) | 1.57 (1.01, 2.44) | .64 |
| Model 2b | 1.41 (1.22, 1.63) | <.001 | 1.44 (1.23, 1.69) | 1.34 (0.98, 1.83) | .68 | 1.39 (1.19, 1.62) | 1.57 (1.01, 2.44) | .57 |
| Model 3c | 1.30 (1.11, 1.53) | .002 | 1.32 (1.10, 1.59) | 1.26 (0.93, 1.72) | .81 | 1.29 (1.09, 1.54) | 1.38 (0.88, 2.16) | .84 |
| Model 4d | 1.34 (1.10, 1.63) | .004 | 1.39 (1.10, 1.74) | 1.25 (0.90, 1.74) | .60 | 1.36 (1.11, 1.68) | 1.20 (0.74, 1.93) | .62 |
Data are adjusted RR and 95% CI on risk of carotid artery plaque per standard deviation increment in log-transformed metabolite variables.
Abbreviations: CI, confidence interval; HIV, human immunodeficiency virus; RR, risk ratio.
aAdjusted for age, sex, race/ethnicity, education, study site, current smoking, and history of hepatitis C virus.
bFurther adjusted for human immunodeficiency virus (HIV) serostatus, HIV treatment status, and baseline viral load level.
cFurther adjusted for systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, antihypertensive medication use, lipid-lowering medication use, and body mass index (total sample size was reduced to 705 due to missing data on cardiovascular disease risk factors).
dFurther adjusted for serum levels of soluble(s) CD14, sCD163, galectin-3, Gal-3 binding protein, and interleukin-6 (total sample size was reduced to 673 due to missing data on inflammation and immune activation markers).