General characteristics of the study population based on insulin levels
| Variables | Insulin levels | P value | |||||||
| Total n=321 | Low | Middle | High | ||||||
| n=110 | (≤4.8) | n=107 | (4.9–7.8) | n=104 | (≥7.9) | ||||
| Age (year) | 63.91 | ±8.32 | 64.23 | ±8.32 | 64.47 | ±8.67 | 63.01 | ±7.93 | 0.40 |
| BMI (kg/m2) | 24.36 | ±3.53 | 22.41 | ±3.14 | 24.41 | ±2.73 | 26.37 | ±3.54 | <0.001 |
| Waist circumference (cm) | 84.23 | ±9.51 | 79.69 | ±7.57 | 83.78 | ±8.63 | 89.51 | ±9.65 | <0.001 |
| SBP (mmHg) | 129.02 | ±16.59 | 123.69 | ±17.36 | 129.52 | ±14.51 | 134.13 | ±16.20 | <0.001 |
| DBP (mmHg) | 77.01 | ±10.90 | 75.43 | ±11.80 | 76.92 | ±10.03 | 78.79 | ±10.60 | 0.08 |
| ALT (U/L) | 21.74 | ±11.06 | 18.94 | ±7.81 | 20.33 | ±9.25 | 26.15 | ±14.05 | <0.001 |
| Creatinine (mg/dL) | 0.76 | ±0.44 | 0.69 | ±0.17 | 0.85 | ±0.66 | 0.75 | ±0.34 | 0.03 |
| FPG (mg/dL) | 89.10 | ±9.93 | 85.29 | ±9.11 | 89.18 | ±8.52 | 93.05 | ±10.60 | <0.001 |
| HDL-C (mg/dL) | 55.70 | ±14.05 | 60.93 | ±14.85 | 55.59 | ±13.17 | 50.28 | ±11.94 | <0.001 |
| Insulin (μU/mL) | 7.10 | ±4.14 | 3.60 | ±0.94 | 6.21 | ±0.86 | 11.72 | ±4.02 | <0.001 |
| LDL-C (mg/dL) | 121.48 | ±32.05 | 118.90 | ±34.55 | 126.03 | ±31.01 | 119.53 | ±30.10 | 0.20 |
| T-cholesterol (mg/dL) | 200.61 | ±35.20 | 198.85 | ±36.98 | 203.81 | ±35.12 | 119.18 | ±33.43 | 0.52 |
| TG (mg/dL) | 117.34 | ±60.61 | 95.39 | ±45.13 | 111.04 | ±49.83 | 147.05 | ±72.48 | <0.001 |
| Current smoking, n(%) | 34 | (10.6) | 14 | (12.7) | 11 | (10.3) | 9 | (8.7) | 0.62 |
| Marital status (single), n(%) | 54 | (16.8) | 22 | (20.0) | 14 | (13.1) | 18 | (17.3) | 0.39 |
| Men, n(%) | 111 | (34.6) | 41 | (37.3) | 39 | (36.4) | 31 | (29.8) | 0.46 |
| Regular exercise, n(%) | 264 | (82.2) | 92 | (83.6) | 96 | (89.7) | 76 | (73.1) | 0.01 |
| Vegetarian, n(%) | 20 | (6.2) | 7 | (6.4) | 7 | (6.5) | 6 | (5.8) | 0.97 |
| HTN, n(%) | 150 | (46.7) | 43 | (39.1) | 47 | (43.9) | 60 | (57.7) | 0.02 |
| Hyperlipidaemia, n(%) | 204 | (63.6) | 58 | (52.7) | 69 | (64.5) | 77 | (74.0) | 0.005 |
| Metabolic syndrome, n(%) | 90 | (28.0) | 11 | (10.0) | 23 | (21.5) | 56 | (53.8) | <0.001 |
Clinical characteristics are expressed as the mean±SD for continuous variables and n(%) for categorical variables. P values were derived from one-way analysis of variance (ANOVA) for continuous variables and χ2 test for categorical variables.
Notes, ranges of FI levels of different tertile groups are shown in brackets at the top of the table, units in μU/mL.
ALT, alanine aminotransferase; BMI, body mass index; DBP, diastolic blood pressure; FPG, fasting plasma glucose; HDL-C, high-density lipoprotein cholesterol; HTN, hypertension; LDL-C, low-density lipoprotein cholesterol; SBP, systolic blood pressure; TG, triglyceride.