Table 1

General characteristics of the study population based on insulin levels

VariablesInsulin levelsP value
Total n=321LowMiddleHigh
n=110(≤4.8)n=107(4.9–7.8)n=104(≥7.9)
Age (year)63.91±8.3264.23±8.3264.47±8.6763.01±7.930.40
BMI (kg/m2)24.36±3.5322.41±3.1424.41±2.7326.37±3.54<0.001
Waist circumference (cm)84.23±9.5179.69±7.5783.78±8.6389.51±9.65<0.001
SBP (mmHg)129.02±16.59123.69±17.36129.52±14.51134.13±16.20<0.001
DBP (mmHg)77.01±10.9075.43±11.8076.92±10.0378.79±10.600.08
ALT (U/L)21.74±11.0618.94±7.8120.33±9.2526.15±14.05<0.001
Creatinine (mg/dL)0.76±0.440.69±0.170.85±0.660.75±0.340.03
FPG (mg/dL)89.10±9.9385.29±9.1189.18±8.5293.05±10.60<0.001
HDL-C (mg/dL)55.70±14.0560.93±14.8555.59±13.1750.28±11.94<0.001
Insulin (μU/mL)7.10±4.143.60±0.946.21±0.8611.72±4.02<0.001
LDL-C (mg/dL)121.48±32.05118.90±34.55126.03±31.01119.53±30.100.20
T-cholesterol (mg/dL)200.61±35.20198.85±36.98203.81±35.12119.18±33.430.52
TG (mg/dL)117.34±60.6195.39±45.13111.04±49.83147.05±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.