Table 1 Baseline characteristics of the study subjects according to quartiles of fasting glucose variability
Characteristics | VIM Q1 (n = 156061) | VIM Q2 (n = 156058) | VIM Q3 (n = 156060) | VIM Q4 (n = 156058) | P value |
|---|---|---|---|---|---|
Age (years) | 58.6 ± 10.6 | 57.4 ± 11.0 | 56.5 ± 11.7 | 54.7 ± 13.1 | < 0.001 |
Sex, male (%) | 98563 (63.2) | 101947 (65.3) | 103675 (66.4) | 106869 (68.5) | < 0.001 |
BMI (kg/m2) | 24.9 ± 3.0 | 25.0 ± 3.1 | 25.1 ± 3.2 | 24.9 ± 3.4 | < 0.001 |
WC (cm) | 85.2 ± 8.0 | 85.5 ± 8.0 | 85.6 ± 8.2 | 85.1 ± 8.6 | < 0.001 |
Systolic BP (mmHg) | 128.6 ± 15.2 | 128.8 ± 15.0 | 128.6 ± 15.0 | 127.8 ± 15.0 | < 0.001 |
Fasting glucose (mg/dL) | 143.8 ± 40.5 | 142.0 ± 38.0 | 142.4 ± 41.1 | 146.2 ± 50.7 | < 0.001 |
Triglyceride (mg/dL) | 141.9 (141.5–142.3) | 146.7 (146.3–147.1) | 149.7 (149.3–150.1) | 148.8 (148.3–149.2) | < 0.001 |
HDL-C (mg/dL) | 52.0 ± 21.8 | 51.8 ± 21.2 | 51.6 ± 21.1 | 51.7 ± 20.9 | < 0.001 |
LDL-C (mg/dL) | 111.6 ± 45.0 | 111.9 ± 44.4 | 111.4 ± 44.7 | 110.3 ± 46.5 | < 0.001 |
GLU_SD (mg/dL) | 12.4 ± 9.8 | 22.7 ± 14.1 | 32.3 ± 18.7 | 47.1 ± 25.3 | < 0.001 |
GLU_CV (%) | 8.1 ± 4.0 | 15.5 ± 5.0 | 22.9 ± 6.9 | 35.5 ± 11.9 | < 0.001 |
GLU_VIM (%) | 4.1 ± 1.8 | 9.6 ± 1.3 | 14.6 ± 1.7 | 24.3 ± 5.7 | < 0.001 |
GLU_ARV (mg/dL) | 15.2 ± 12.9 | 27.0 ± 18. 8 | 37.8 ± 25.2 | 52.4 ± 33.7 | < 0.001 |
Current smoker (%) | 33185 (21.3) | 37301 (23.9) | 42135 (27) | 48736 (31.2) | < 0.001 |
Heavy drinking (%) | 14997 (9.6) | 15563 (10.0) | 15755 (10.1) | 14992 (9.6) | < 0.001 |
Regular exercise (%) | 40718 (26.0) | 38546 (24.7) | 36142 (23.2) | 32955 (21.1) | < 0.001 |
Comorbidities | |||||
 Hypertension (%) | 89659 (57.5) | 87808 (56.3) | 84796 (54.3) | 78148 (50.1) | < 0.001 |
 Dyslipidemia (%) | 60077 (38.5) | 58915 (37.8) | 56500 (36.2) | 50461 (32.3) | < 0.001 |
 CKD (%) | 15740 (10.1) | 15962 (10.2) | 16598 (10.7) | 17320 (11.1) | < 0.001 |
 Heart disease (%) | 6265 (4.6) | 5786 (4.3) | 5189 (4.0) | 4564 (3.7) | < 0.001 |
 Any malignancy (%) | 4125 (2.6) | 3930 (2.5) | 3772 (2.4) | 3892 (2.5) | 0.001 |
Income (lower 20%, %) | 34507 (22.1) | 35412 (22.7) | 37482 (24.0) | 39595 (25.4) | < 0.001 |
Antidiabetic medication | |||||
 Metformin | 84747 (54.3) | 77947 (50.0) | 72119 (46.2) | 62185 (39.9) | < 0.001 |
 Sulfonylurea | 81607 (52.3) | 77767 (49.8) | 74710 (47.9) | 66155 (42.4) | < 0.001 |
 Meglitinide | 4246 (2.7) | 4050 (2.6) | 3850 (2.5) | 3785 (2.4) | < 0.001 |
 Thiazolidinedione | 14054 (9.0) | 13354 (8.6) | 12355 (7.9) | 10933 (7.0) | <0.001 |
 DPP-4 inhibitor | 13802 (8.8) | 12730 (8.2) | 11766 (7.5) | 9535 (6.1) | < 0.001 |
 a-Glucosidase inhibitor | 21803 (14.0) | 20564 (13.2) | 20055 (12.9) | 18458 (11.8) | <  0.001 |
 Insulin | 10064 (6.5) | 9936 (6.4) | 10655 (6.8) | 13320 (8.5) | < 0.001 |
Number of oral anti-diabetic medications |  |  |  |  | < 0.001 |
 0 | 42298 (27.1) | 51240 (32.8) | 58967 (37.8) | 72375 (46.4) |  |
 1 | 38976 (25.0) | 33797 (21.7) | 29285 (18.8) | 23217 (14.9) |  |
 2 | 48766 (31.3) | 45997 (29.5) | 43216 (27.7) | 38441 (24.6) |  |
 ≥ 3 | 26021 (16.7) | 25024 (16.0) | 24592 (15.8) | 22025 (14.1) |  |
Duration of diabetes ≥5 years (%) | 62489 (40.0) | 55604 (35.6) | 50193 (32.2) | 43641 (28.0) | < 0.001 |
Type 1 diabetes (%) | 3104 (2.0) | 3214 (2.1) | 3745 (2.4) | 5548 (3.6) | < 0.001 |
Number of exams |  |  |  |  | < 0.001 |
 3 | 126421 (81.0) | 113451 (72.7) | 108293 (69.4) | 104468 (66.9) |  |
 4 | 14692 (9.4) | 19227 (12.3) | 21858 (14.0) | 24324 (15.6) |  |
 5 | 14948 (9.6) | 23380 (15.0) | 25909 (16.6) | 27266 (17.5) |  |
Time interval between adjacent exams (years) | 1.8 ± 0.3 | 1.7 ± 0.3 | 1.7 ± 0.3 | 1.7 ± 0.3 | <0.001 |