Table 1.
Clinical and demographic characteristics of the study population.
| Training set | Testing set | |||||
|---|---|---|---|---|---|---|
| Variables | Control | DM | DR | Control | DM | DR |
| Age, years | 56.0 (54.0,62.0) | 53.0 (48.0,59.0) | 57.0 (54.0,65.0) | 58.3 ± 7.0 | 56.0 ± 12.0 | 57.0 ± 10.0 |
| Male, # (%) | 36 (73.5) | 29 (59.2) | 26 (53.1) | 17 (85.0) | 9 (45.0) | 10 (50.0) |
| BMI, kg/m2 | 24.5 (23.4,26.7) | 23.9 (22.1,27.4) | 24.1 (22.4,27.0) | 24.7 (23.2,26.9) | 24.8 (23.1,26.1) | 25.2 (22.4,26.2) |
| Fpg, mmol/L | 5.4 (5.0,5.7) | 8.3 (6.9,12.0) | 8.9 (6.7,10.9) | 5.3 (5.1,6.4) | 8.6 (6.8,11.6) | 7.3 (5.7,9.1) |
| HbA1c, % | 5.7 (5.4,6.0) | 9.9 (8.2,12.0) | 9.7 (8.7,10.9) | 5.9 ± 0.8 | 9.9 ± 2.0 | 10.3 ± 1.9 |
| LDL, mmol/L | 2.9 ± 0.8 | 2.7 ± 0.9 | 2.6 ± 1.1 | 2.7 ± 0.7 | 2.4 ± 1.2 | 2.5 ± 1.0 |
| HDL, mmol/L | 1.1 (1.0,1.3) | 1.1 (0.8,1.4) | 1.1 (0.9,1.4) | 1.1 (1.0,1.2) | 0.9 (0.8,1.2) | 1.0 (0.8,1.2) |
| TG, mmol/L | 2.0 (1.5,3.0) | 1.6 (1.0,2.1) | 1.4 (1.0,1.7) | 1.9 (1.4,2.7) | 1.8 (1.5,2.4) | 1.5 (1.1,2.3) |
| TC, mmol/L | 5.0 ± 0.9 | 4.8 ± 1.1 | 4.6 ± 1.5 | 4.9 ± 0.9 | 4.5 ± 1.3 | 4.3 ± 1.3 |
| hypertension, # (%) | 17 (34.7) | 12 (24.5) | 21 (42.9) | 2 (10.0) | 10 (50.0) | 10 (50.0) |
| Systolic BP, mm Hg | 124.8 ± 14.4 | 136.8 ± 19.7 | 134.5 ± 17.6 | 140.1 ± 24.8 | ||
| Diastolic BP, mm Hg | 78.0 (73.0,86.0) | 76.0 (70.0,80.0) | 82.6 ± 10.3 | 80.6 ± 11.5 | ||
| Duration of diabetes, years | 8.1 ± 6.2 | 12.2 ± 6.1 | 9.9 ± 6.6 | 12.1 ± 7.8 | ||
| Education, # (%) | ||||||
| Junior high school or below | 25 (53.2) | 23 (51.1) | 10 (52.6) | 13 (65.0) | ||
| High school or above | 22 (46.8) | 22 (48.9) | 9 (47.4) | 7 (35.0) | ||
| Occupation, # (%) | ||||||
| Manual workers | 23 (48.9) | 22 (50.0) | 8 (44.4) | 12 (60.0) | ||
| Mental worker | 10 (21.3) | 8 (18.2) | 5 (27.8) | 3 (15.0) | ||
| Both | 14 (29.8) | 14 (31.8) | 5 (27.8) | 5 (25.0) | ||
| History of diabetes, # (%) | 17 (34.7) | 25 (51.0) | 10 (50.0) | 8 (40.0) | ||
| Smoking habits, # (%) | ||||||
| Non-smokers | 29 (61.7) | 23 (51.1) | 12 (63.2) | 13 (65.0) | ||
| Current smokers | 13 (27.7) | 16 (35.6) | 6 (31.6) | 5 (25.0) | ||
| Ex-smokers | 5 (10.6) | 6 (13.3) | 1 (5.3) | 2 (10.0) | ||
| Alcohol consumption, # (%) | ||||||
| Non-drinkers | 22(46.8) | 20(44.4) | 11(57.9) | 9(45.0) | ||
| Current drinkers | 23(48.9) | 19(42.2) | 7(36.8) | 8(40.0) | ||
| Ex-drinkers | 2(4.3) | 6(13.3) | 1(5.3) | 3(15.0) | ||
BMI body mass index, FPG fasting plasma glucose, HbA1c glycated hemoglobin, HDL high-density lipoprotein, LDL low-density lipoprotein, TG triglyceride, TC total cholesterol, Systolic BP systolic blood pressure, Diastolic BP diastolic blood pressure, Control healthy control group, DM T2DM without DR participants, DR T2DM patients with DR.
Continuous data obeying normal or similar normal distribution were described as mean ± standard deviation (SD) and variance analysis of randomized block design or the paired t-test was applied to compare the differences between the three/two groups. Otherwise, median (1st quartile, 3rd quartile) and Friedman M or Wilcoxon signed-rank tests were used. Categorical data were presented as a number of cases (%) and the McNemar-Bowker test was utilized to compare the differences between the groups.