Characteristics of the study participants according to glucose homeostasis status
| NGT | iIFG | iIGT | P value | |
| Gender (male/female) | 252/226 | 12/9 7.1) | 13/19 | 0.372 |
| Age (years) | 20.05±2.88 | 21.29±3.33 | 20.00±2.36 | 0.154 |
| BMI (kg/m2) | 25.59±5.50 | 28.57±5.30* | 26.64±6.98 | 0.039 |
| Waist circumstance (cm) | 84.84±14.14 | 92.19±13.39* | 88.05±16.51 | 0.038 |
| FAT% | 30.19±10.05 | 35.33±12.71* | 33.83±9.97* | 0.014 |
| SBP (mm Hg) | 114.05±13.35 | 119.22±15.51 | 119.82±16.09* | 0.02 |
| DBP (mm Hg) | 72.62±10.21 | 77.17±10.27* | 76.60±11.55* | 0.019 |
| TG (mmol/L) | 1.08±0.67 | 1.90±2.42*** | 1.32±0.62# | <0.001 |
| LDL-C (mmol/L) | 2.50±0.74 | 2.84±0.86* | 2.65±0.75 | 0.074 |
| Total cholesterol (mmol/L) | 4.31±0.86 | 4.62±1.36 | 4.46±0.83 | 0.207 |
| HDL-C (mmol/L) | 1.43±0.32 | 1.45±0.38 | 1.44±0.29 | 0.983 |
| ALT (IU/L) | 19.05 (18.17 to 19.97) | 22.03 (17.59 to 27.59) | 19.86 (16.55 to 23.83) | 0.432 |
| AST (IU/L) | 18.86 (18.35 to 19.40) | 20.35 (17.81 to 23.24) | 18.32 (16.45 to 20.41) | 0.467 |
| Hs-CRP (mg/L) | 0.55 (0.47 to 0.65) | 0.77 (0.37 to 1.59) | 0.56 (0.31 to 1.03) | 0.693 |
| HbA1c (%) | 5.32±0.29 | 5.60±0.29*** | 5.41±0.31# | <0.001 |
| Glucose (mmol/L) | ||||
| Fasting | 4.81±0.34 | 5.74±0.15*** | 5.01±0.30**### | <0.001 |
| 0.5 hour | 7.73±1.23 | 9.14±1.43*** | 8.72±1.13*** | <0.001 |
| 2 hours | 5.71±0.98 | 6.41±1.04** | 8.40±0.52***### | <0.001 |
| Insulin (mU/L) | ||||
| Fasting | 6.72 (6.30 to 7.18) | 9.83 (7.20 to 13.41)* | 8.53 (6.63 to 10.98) | 0.016 |
| 0.5 hour | 71.49 (67.07 to 76.21) | 65.58 (48.52 to 88.63) | 68.90 (53.77 to 88.30) | 0.832 |
| 2 hours | 34.23 (31.95 to 36.67) | 42.65 (30.72 to 59.20) | 94.28 (72.28 to 122.98)***### | <0.001 |
| Insulin resistance and beta-cell function† | ||||
| HOMA-IR | 1.45 (1.38 to 1.53) | 2.09 (1.63 to 2.68)* | 1.73 (1.42 to 2.12) | 0.007 |
| ISI | 6.23 (5.93 to 6.53) | 5.02 (4.03 to 6.27) | 4.41 (3.69 to 5.29)** | <0.001 |
| HOMA-β | 108.31 (102.84 to 114.04) | 74.89 (58.47 to 95.85)* | 104.06 (85.30 to 127.03) | 0.016 |
| IGI | 1.33 (1.24 to 1.42) | 0.92 (0.66 to 1.27) | 0.89 (0.68 to 1.16)* | 0.002 |
| DIo | 8.24 (7.75 to 8.76) | 4.59 (3.44 to 6.13)*** | 3.93 (3.10 to 4.98)*** | <0.001 |
| Adipokines | ||||
| FGF21 (pg/ml) | 76.93 (69.49 to 85.17) | 107.02 (66.67 to 171.78) | 120.19 (81.42 to 177.42)* | 0.045 |
| RBP4 (μg/mL) | 8.97 (8.68 to 9.27) | 9.59 (8.20 to 11.22) | 9.08 (8.00 to 10.31) | 0.707 |
| Leptin (ng/mL) | 1.78 (1.62 to 1.96) | 2.48 (1.59 to 3.86) | 2.67 (1.86 to 3.82)* | 0.043 |
| Adiponectin (μg/mL) | 6.78 (6.41 to 7.18) | 6.88 (5.21 to 9.10) | 5.41 (4.34 to 6.75) | 0.148 |
| Leptin/adiponectin | 26.32 (23.53 to 29.44) | 35.57 (20.65 to 61.27) | 49.33 (32.09 to 75.82)** | 0.014 |
| MetS components | ||||
| Central obesity, n (%) | 250 (52.3) | 15 (71.4) | 20 (62.5) | 0.134 |
| BP ≥130/85 mm Hg, n (%) | 80 (16.7) | 8 (38.1)* | 12 (37.5)** | 0.001 |
| TG ≥1.7 mmol/L, n (%) | 62 (13.0) | 4 (19.0) | 9 (28.1)* | 0.045 |
| Low HDL-C, n (%) | 41 (8.6) | 1 (4.8) | 3 (9.4) | 0.924 |
| MetS, n (%) | 36 (7.5) | 3 (14.3) | 15 (46.9)***# | <0.001 |
| NAFLD, n (%) | 127 (28.5) | 12 (57.1)** | 13 (40.6) | 0.009 |
| NAFLD, moderate to severe, n (%) | 40 (9.0) | 3 (14.3) | 9 (28.1)** | 0.003 |
All values are reported as mean±SD or geometric mean (95% CI) unless otherwise indicated.
P values were calculated from the analysis of covariance or general linear regression model with post hoc comparisons for continuous variables and χ2 test or Fisher exact test for categorical variables. Differences versus NGT are indicated as *p<0.05, **p<0.01, and ***p<0.001. Differences versus impaired fasting glucose are indicated as #p<0.05, ##p<0.01, and ###p<0.001. Values in bold are significant at p<0.05.
†Adjusted for age, gender and BMI.
ALT, alanine aminotransferase; AST, aspartate transaminase; BMI, body mass index; BP, blood pressure; DBP, diastolic blood pressure; DIo, oral disposition index; FAT%, fat mass percentage; FGF21, fibroblast growth factor 21; HbA1c, hemoglobin A1c; HDL-C, high-density lipoprotein cholesterol; HOMA-β, Homeostasis model assessment of β-cell function; HOMA-IR, homeostasis model assessment of insulin resistance; Hs-CRP, high-sensitivity C reactive protein; IGI, insulinogenic index; iIFG, isolated impaired fasting glucose; iIGT, isolated impaired glucose tolerance; ISI, insulin sensitivity index; LDL-C, low-density lipoprotein cholesterol; MetS, metabolic syndrome; NAFLD, non-alcoholic fatty liver disease; NGT, normal glucose tolerance; RBP4, retinol binding protein 4; SBP, systolic blood pressure; TG, triglyceride.