Table 1.
Characteristics of the participants according to diabetes status.
| Variables | NGT | IFG | T2DM | p Value | |
|---|---|---|---|---|---|
| IFG vs. NGT | T2DM vs. NGT | ||||
| Subjects, n | 897 | 913 | 849 | ||
| Age, (years) | 61 (54, 66) | 61 (54, 66) | 61 (54, 66) | 0.961 | 0.970 |
| Male, n (%) | 344 (38.35) | 352 (38.55) | 324 (38.16) | 0.929 | 0.936 |
| BMI, (kg/m2) | 23.42 (21.18, 25.75) | 24.22 (22.12, 26.53) | 25.43 (23.48, 27.68) | <0.001 | <0.001 |
| Smoking status, n (%) | 0.700 | 0.038 | |||
| Never smoking | 667 (74.36) | 692 (75.79) | 625 (73.62) | ||
| Previous smoker | 57 (6.35) | 59 (6.46) | 80 (9.42) | ||
| Current smoker | 173 (19.29) | 162 (17.74) | 144 (16.96) | ||
| Alcohol intake, n (%) | 0.506 | 0.298 | |||
| Never drinking | 737 (82.16) | 766 (83.90) | 675 (79.51) | ||
| Previous drinker | 48 (5.35) | 49 (5.37) | 58 (6.83) | ||
| Current drinker | 112 (12.49) | 98 (10.73) | 116 (13.66) | ||
| Physical activity, n (%) | 0.520 | 0.040 | |||
| Low | 213 (23.75) | 238 (26.07) | 245 (28.86) | ||
| Mediate | 453 (50.50) | 446 (48.85) | 388 (45.70) | ||
| High | 231 (25.75) | 229 (25.08) | 216 (25.44) | ||
| Average monthly individual income, n (%) | 0.228 | 0.309 | |||
| <500, CNY | 352 (39.24) | 381 (41.73) | 345 (40.64) | ||
| 500~, CNY | 279 (31.10) | 294 (32.20) | 236 (27.80) | ||
| 1000~, CNY | 266 (29.65) | 238 (26.07) | 268 (31.57) | ||
| Level of education, n (%) | 0.749 | 0.515 | |||
| Never attended school | 238 (26.53) | 228 (24.97) | 207 (24.38) | ||
| Primary school | 271 (30.21) | 281 (30.78) | 255 (30.03) | ||
| Junior secondary and above | 388 (43.26) | 404 (44.25) | 387 (45.58) | ||
| Family history of T2DM, n (%) | 15 (1.67) | 14 (1.53) | 45 (5.30) | 0.814 | <0.001 |
| SBP, (mmHg) | 118.00 (108.00, 131.00) | 121.00 (110.00, 134.00) | 125.00 (114.00, 138.00) | <0.001 | <0.001 |
| PP, (mmHg) | 45.00 (39.00, 53.00) | 49.00 (42.00, 57.00) | 47.00 (39.00, 56.00) | 0.022 | <0.001 |
| TC, (mmol/L) | 4.60 (0.80) | 4.83 (4.25, 5.44) | 4.79, (4.21, 5.50) | <0.001 | <0.001 |
| TG, (mmol/L) | 1.41 (1.00, 1.95) | 1.64 (1.11, 2.31) | 1.92 (1.34, 2.94) | <0.001 | <0.001 |
| HDL-C, (mmol/L) | 1.37 (1.16, 1.62) | 1.32 (1.12, 1.57) | 1.23 (1.02, 1.47) | 0.010 | <0.001 |
| LDL-C, (mmol/L) | 2.82 (0.71) | 3.00 (2.47, 3.50) | 2.83 (0.95) | <0.001 | 0.583 |
| FPG, (mmol/L) | 4.94 (0.46) | 5.30 (4.89, 5.82) | 7.94 (7.00, 10.21) | <0.001 | <0.001 |
| HbA1c, (%) | 5.30 (5.10, 5.50) | 5.90 (5.70, 6.00) | 7.40 (6.60, 8.90) | <0.001 | <0.001 |
| INS, (uIU/mL) | 11.94 (9.31, 15.20) | 12.59 (9.86, 16.33) | 14.12 (11.40, 18.52) | 0.001 | <0.001 |
| Testosterone, (ng/mL) | |||||
| Male | 2.30 (1.70, 3.00) | 2.00 (1.40, 2.70) | 1.80 (1.30, 2.50) | <0.001 | <0.001 |
| Female | 0.10 (0.02, 0.10) | 0.10 (0.02, 0.10) | 0.10 (0.10, 0.10) | 0.053 | <0.001 |
| 25(OH)D3, (ng/mL) | 23.07 (19.02, 28.00) | 22.07 (18.09, 27.03) | 22.87 (18.30, 28.04) | <0.001 | 0.182 |
| 25(OH)D2, (ng/mL) | 7.60 (6.04, 9.84) | 6.46 (5.43, 7.85) | 6.30 (5.23, 7.80) | <0.001 | <0.001 |
| 25(OH)D, (ng/mL) | 31.12 (26.29, 37.50) | 29.26 (24.61, 34.23) | 29.77 (24.84, 35.51) | <0.001 | <0.001 |
Values are the mean (standard deviation) or median (inter-quartile range) for continuous variables and the number (percentages) for the categorical variable. p values were calculated using the t-test or Mann–Whitney U test and chi-square test. Abbreviations: BMI, body mass index; FPG, fasting plasm glucose; HbA1c, glycosylated hemoglobin; HDL-C, high-density lipoprotein cholesterol; IFG, impaired fasting glucose; INS, insulin; LDL-C, low-density lipoprotein cholesterol; NGT, normal glucose tolerance; PP, pulse pressure; CNY, renminbi; SBP, systolic blood pressure; TC, triglycerides; TG, triglyceride; T2DM, type 2 diabetes mellitus.