Table 1.
Comparison of characteristics according to the quartile of TyG index (n = 15,721)
| Quartile of TyG index | P valuea | ||||
|---|---|---|---|---|---|
| Quartile 1 (n = 3928) |
Quartile 2 (n = 3932) |
Quartile 3 (n = 3930) |
Quartile 4 (n = 3931) |
||
| Range of TyG index | 6.659–8.055 | 8.056–8.465 | 8.466–8.919 | 8.920–12.208 | |
| Survey year | 0.353 | ||||
| 2016 | 947 (24.1) | 930 (23.7) | 970 (24.7) | 1014 (25.8) | |
| 2017 | 982 (25.0) | 1000 (25.4) | 1016 (25.9) | 946 (24.1) | |
| 2018 | 979 (24.9) | 1022 (26.0) | 971 (24.7) | 998 (25.4) | |
| 2019 | 1020 (26.0) | 980 (24.9) | 973 (24.8) | 973 (24.8) | |
| Age (years) | 40.0 ± 14.6 | 44.4 ± 15.1* | 47.5 ± 14.9* | 48.1 ± 13.8* | < 0.001 |
| 19–29 | 1120 (28.5) | 722 (18.4) | 512 (13.0) | 349 (8.9) | < 0.001 |
| 30–39 | 981 (25.0) | 900 (22.9) | 759 (19.3) | 805 (20.5) | |
| 40–49 | 889 (22.6) | 901 (22.9) | 932 (23.7) | 1066 (27.1) | |
| 50–64 | 659 (16.8) | 975 (24.8) | 1155 (29.4) | 1200 (30.5) | |
| ≥ 65 | 279 (7.1) | 434 (11.0) | 572 (14.6) | 511 (13.0) | |
| Sex | < 0.001 | ||||
| Male | 991 (25.2) | 1427 (36.3) | 1906 (48.5) | 2496 (63.5) | |
| Female | 2937 (74.8) | 2505 (63.7) | 2024 (51.5) | 1435 (36.5) | |
| Marital status | < 0.001 | ||||
| Married | 2381 (60.6) | 2657 (67.6) | 2808 (71.5) | 2860 (72.8) | |
| Widowed, separated, or divorced | 261 (6.7) | 326 (8.3) | 369 (9.4) | 390 (9.9) | |
| Single | 1285 (32.7) | 948 (24.1) | 752 (19.1) | 679 (17.3) | |
| Education level | < 0.001 | ||||
| Elementary school graduate or less | 252 (6.4) | 346 (8.8) | 428 (10.9) | 458 (11.7) | |
| Middle school graduate | 190 (4.8) | 248 (6.3) | 315 (8.0) | 302 (7.7) | |
| High school graduate | 1334 (34.0) | 1378 (35.1) | 1314 (33.4) | 1326 (33.7) | |
| College graduate or more | 2007 (51.1) | 1787 (45.5) | 1704 (43.4) | 1627 (41.4) | |
| Unknown | 145 (3.7) | 173 (4.4) | 169 (4.3) | 218 (5.6) | |
| Household income quartiles | < 0.001 | ||||
| Quartile 1 (poorest) | 396 (10.1) | 473 (12.1) | 486 (12.4) | 544 (13.9) | |
| Quartile 2 | 907 (23.2) | 912 (23.3) | 949 (24.2) | 957 (24.4) | |
| Quartile 3 | 1148 (29.3) | 1198 (30.6) | 1182 (30.2) | 1197 (30.5) | |
| Quartile 4 (richest) | 1463 (37.4) | 1339 (34.1) | 1298 (33.2) | 1223 (31.2) | |
| Smoking status | < 0.001 | ||||
| Non-smoker | 3083 (79.0) | 2704 (69.5) | 2352 (60.5) | 1743 (44.8) | |
| Former smoker | 423 (10.8) | 587 (15.1) | 731 (18.8) | 908 (23.4) | |
| Current smoker | 397 (10.2) | 600 (15.4) | 807 (20.8) | 1237 (31.8) | |
| Frequency of heavy episodic drinking | < 0.001 | ||||
| Dose not drink | 790 (20.2) | 888 (22.8) | 880 (22.6) | 730 (18.8) | |
| Never in past year | 1132 (29.0) | 1124 (28.9) | 947 (24.3) | 807 (20.8) | |
| Once a month or less | 1470 (37.7) | 1272 (32.7) | 1245 (32.0) | 1161 (29.9) | |
| Once a week | 414 (10.6) | 470 (12.1) | 593 (15.2) | 826 (21.2) | |
| Almost daily | 98 (2.5) | 139 (3.6) | 227 (5.8) | 364 (9.4) | |
| Family history of hypertension | < 0.001 | ||||
| No | 2358 (60.0) | 2363 (60.1) | 2386 (60.7) | 2313 (58.8) | |
| Yes | 1471 (37.5) | 1432 (36.4) | 1387 (35.3) | 1425 (36.3) | |
| Unknown | 99 (2.5) | 137 (3.5) | 157 (4) | 193 (4.9) | |
| BMI (kg/m2) | 21.8 ± 2.9 | 22.8 ± 3.2* | 24.0 ± 3.4* | 25.4 ± 3.5* | < 0.001 |
| Underweight (< 18.5) | 367 (9.4) | 250 (6.4) | 107 (2.7) | 36 (0.9) | < 0.001 |
| Normal (18.5–22.9) | 2415 (61.6) | 2020 (51.5) | 1512 (38.5) | 932 (23.8) | |
| Overweight (23.0–24.9) | 641 (16.4) | 819 (20.9) | 994 (25.3) | 979 (24.9) | |
| Obesity (≥ 25.0) | 497 (12.7) | 836 (21.3) | 1311 (33.4) | 1978 (50.4) | |
| Waist circumference (cm) | 74.7 ± 8.3 | 78.4 ± 9.0* | 82.6 ± 9.4* | 87.3 ± 9.1* | < 0.001 |
| Normal (M: < 90, F: < 85) | 3620 (92.3) | 3307 (84.2) | 2839 (72.4) | 2234 (57.0) | < 0.001 |
| Abdominal obesity (M: ≥ 90, F: ≥ 85) | 304 (7.8) | 620 (15.8) | 1082 (27.6) | 1688 (43.0) | |
| FPG (mg/dL) | 88.9 ± 7.6 | 92.8 ± 8.1* | 96.2 ± 10.8* | 106.3 ± 28.0* | < 0.001 |
| HbA1c (%) | 5.3 ± 0.3 | 5.4 ± 0.3* | 5.5 ± 0.4* | 5.8 ± 0.9* | < 0.001 |
| Fasting insulin (uIU/mL)a | 5.8 ± 3.4 | 7.2 ± 4.7* | 8.4 ± 5.4* | 11.6 ± 11.0* | < 0.001 |
| HOMA-IRa | 1.3 ± 0.8 | 1.7 ± 1.1* | 2.0 ± 1.4* | 3.1 ± 3.6* | < 0.001 |
| Non-insulin resistant (< 2.5) | 959 (94.1) | 840 (85.7) | 741 (76.2) | 515 (52.9) | < 0.001 |
| Insulin resistant (≥ 2.5) | 60 (5.9) | 140 (14.3) | 232 (23.8) | 458 (47.1) | |
| Triglycerides (mg/dL) | 53.9 ± 11.3 | 84.9 ± 11.6* | 124.5 ± 19.3* | 249.7 ± 147.1* | < 0.001 |
| Total cholesterol (mg/dL) | 182.6 ± 31.3 | 193.3 ± 32.1* | 202.8 ± 33.5* | 214.4 ± 37.1* | < 0.001 |
| HDL-cholesterol (mg/dL) | 60.5 ± 12.3 | 55.5 ± 11.8* | 50.8 ± 11.2* | 44.3 ± 9.9* | < 0.001 |
| LDL-cholesterol (mg/dL) | 111.3 ± 27.5 | 120.8 ± 29.4* | 127.2 ± 31.6* | 126.8 ± 33.8* | < 0.001 |
| AST (IU/L) | 19.9 ± 9.2 | 21.0 ± 9.6* | 22.3 ± 9.9* | 26.7 ± 19.5* | < 0.001 |
| ALT (IU/L) | 15.5 ± 11.0 | 18.0 ± 13.2* | 22.2 ± 18.3* | 31.1 ± 26.1* | < 0.001 |
Data are presented as n (%) or mean ± standard deviation
TyG triglyceride and glucose, BMI body mass index, FPG fasting plasma glucose, HbA1c hemoglobin A1c, HOMA-IR homeostatic model assessment for insulin resistance, HDL high-density lipoprotein, LDL low-density lipoprotein, AST aspartate transaminase, ALT alanine aminotransferase
*Represents values significantly different (P < 0.05) from control group (the lowest TyG quartile) by the one-way ANOVA followed by the Dunnett's post-hoc analysis
aFasting insulin and HOMA-IR were analyzed only for 3945 subjects who participated in the 2019 KNHANES