Table 3.
Association between the peak intensity of the four metabolites and the odds of diabetic retinopathy
| Metabolites | N | Cases (%) | Crude | Adjusted* | ||
| OR (95% CI) | P value | OR (95% CI) | P value | |||
| Phenylacetylglutamine | ||||||
| Per IQR | 4.45 (2.10 to 9.43) | <0.001 | 4.64 (1.98 to 10.88) | <0.001 | ||
| Quartiles | ||||||
| Q1 | 23 | 3 (13) | 1.00 (1.00 to 1.00) | Ref. | 1.00 (1.00 to 1.00) | Ref. |
| Q2 | 23 | 13 (57) | 8.67 (2.00 to 37.58) | 0.004 | 12.05 (2.34 to 61.98) | 0.003 |
| Q3 | 23 | 13 (57) | 8.67 (2.00 to 37.58) | 0.004 | 11.78 (2.27 to 61.00) | 0.003 |
| Q4 | 23 | 17 (74) | 18.89 (4.09 to 87.17) | <0.001 | 23.01 (3.98 to 133.20) | <0.001 |
| P for trend | <0.001 | 0.001 | ||||
| Linoleic acid | ||||||
| Per IQR | 0.26 (0.14 to 0.49) | <0.001 | 0.22 (0.11 to 0.45) | <0.001 | ||
| Quartiles | ||||||
| Q1 | 23 | 19 (83) | 1.00 (1.00 to 1.00) | Ref. | 1.00 (1.00 to 1.00) | Ref. |
| Q2 | 23 | 15 (65) | 0.40 (0.10 to 1.57) | 0.186 | 0.30 (0.07 to 1.42) | 0.129 |
| Q3 | 23 | 9 (39) | 0.14 (0.04 to 0.53) | 0.004 | 0.11 (0.02 to 0.54) | 0.006 |
| Q4 | 23 | 3 (13) | 0.03 (0.01 to 0.16) | <0.001 | 0.02 (0.00 to 0.14) | <0.001 |
| P for trend | <0.001 | <0.001 | ||||
| Nicotinuric acid | ||||||
| Per IQR | 2.32 (1.42 to 3.78) | 0.001 | 2.50 (1.47 to 4.25) | 0.001 | ||
| Quartiles | ||||||
| Q1 | 23 | 7 (30) | 1.00 (1.00 to 1.00) | Ref. | 1.00 (1.00 to 1.00) | Ref. |
| Q2 | 23 | 10 (44) | 1.76 (0.52 to 5.91) | 0.361 | 1.45 (0.39 to 5.41) | 0.578 |
| Q3 | 23 | 11 (48) | 2.10 (0.63 to 7.01) | 0.230 | 1.68 (0.48 to 5.84) | 0.415 |
| Q4 | 23 | 18 (78) | 8.23 (2.18 to 31.13) | 0.002 | 13.02 (2.79 to 60.71) | 0.001 |
| P for trend | 0.002 | 0.002 | ||||
| Ornithine | ||||||
| Per IQR | 1.71 (1.09 to 2.69) | 0.020 | 1.80 (1.12 to 2.89) | 0.015 | ||
| Quartiles | ||||||
| Q1 | 23 | 10 (44) | 1.00 (1.00 to 1.00) | Ref. | 1.00 (1.00 to 1.00) | Ref. |
| Q2 | 23 | 9 (39) | 0.84 (0.26 to 2.71) | 0.765 | 0.74 (0.21 to 2.61) | 0.643 |
| Q3 | 23 | 10 (44) | 1.00 (0.31 to 3.21) | 1.000 | 1.04 (0.30 to 3.64) | 0.948 |
| Q4 | 23 | 17 (74) | 3.68 (1.06 to 12.77) | 0.040 | 4.46 (1.14 to 17.39) | 0.031 |
| P for trend | 0.043 | 0.028 | ||||
In the present study, the T2DM duration for each participant was obtained mainly by the self-report and highly correlated to age. Furthermore, it might be inaccurate since many people may be suffering from unnoticed T2DM for a long time. So, to avoid collinearity and overfitting, it was not included in the multiple generalized linear regression models, although it was not comparable between the cases and controls.
*Adjusted for age, smoking habits and therapy history.
Q1, the first quartile; Q2, the second quartile; Q3, the third quartile; Q4, the fourth quartile; Ref., reference; T2DM, type 2 diabetes mellitus.