Background
Methods
Study population and design
Assessment of covariates
Assessment of TyG index
Ascertainment of mortality
Statistical analysis
Results
Baseline characteristics of study participants
Characteristics | Quartiles of TyG index | P value | ||||
---|---|---|---|---|---|---|
overall | Q1(6.80–8.56) | Q2(8.56–8.96) | Q3(8.96–9.40) | Q4(9.40-12.55) | ||
N(%) | 1072 | 268(25.00) | 267(24.90) | 269(25.10) | 268(25.00) | |
Age, years, mean(SD) | 66.54(0.45) | 69.03(0.74) | 66.89(0.83) | 67.09(0.81) | 63.49(0.86) | <0.001 |
Gender, n(%) | ||||||
Male | 436(40.78) | 104(43.45) | 108(42.98) | 113(40.67) | 111(36.38) | 0.53 |
Female | 636(59.22) | 164(56.55) | 159(57.02) | 156(59.33) | 157(63.62) | |
BMI, kg/m2, n(%) | <0.001 | |||||
<24 | 119(10.93) | 48(19.17) | 30(11.91) | 23( 7.91) | 18( 5.95) | |
≥24 | 953(89.07) | 220(80.83) | 237(88.09) | 246(92.09) | 250(94.05) | |
Race, n(%) | 0.002 | |||||
Black | 218(11.88) | 83(18.95) | 53(11.90) | 43( 8.84) | 39( 8.92) | |
Mexican | 126( 4.83) | 18(3.08) | 30(4.66) | 33(4.51) | 45(6.81) | |
White | 590(74.22) | 132(67.29) | 142(71.72) | 165(80.88) | 151(75.92) | |
Other | 138( 9.07) | 35(10.68) | 42(11.72) | 28( 5.76) | 33( 8.35) | |
Education, n(%) | 0.48 | |||||
High school grad or equivalent | 275(28.83) | 62(25.48) | 65(28.50) | 76(29.15) | 72(31.71) | |
Less than high school | 363(24.97) | 79(22.68) | 88(23.27) | 90(25.53) | 106(28.08) | |
Some college or above | 434(46.20) | 127(51.84) | 114(48.24) | 103(45.31) | 90(40.21) | |
Alcohol, n(%) | 0.70 | |||||
Former | 344(30.12) | 85(28.23) | 86(30.26) | 86(29.61) | 87(32.12) | |
Heavy | 105( 9.27) | 21( 7.88) | 30(11.77) | 23( 6.78) | 31(10.41) | |
Mild | 365(39.04) | 101(39.71) | 88(37.73) | 90(41.26) | 86(37.57) | |
Moderate | 85( 7.39) | 22(10.43) | 20( 6.72) | 16( 5.08) | 27( 7.85) | |
Never | 173(14.17) | 39(13.75) | 43(13.51) | 54(17.27) | 37(12.05) | |
Smoking status, n(%) | 0.52 | |||||
Former | 434(42.60) | 109(42.28) | 103(42.82) | 111(40.44) | 111(44.82) | |
Never | 446(39.11) | 122(44.39) | 110(35.84) | 110(41.33) | 104(35.69) | |
Now | 192(18.30) | 37(13.32) | 54(21.34) | 48(18.23) | 53(19.49) | |
Family poverty income ratio, mean (SD) | 2.54(0.06) | 2.50(0.13) | 2.46(0.14) | 2.60(0.12) | 2.61(0.14) | 0.86 |
Hypertension, n(%) | 0.80 | |||||
No | 181(17.34) | 38(14.73) | 54(19.07) | 41(17.22) | 48(17.92) | |
Yes | 891(82.66) | 230(85.27) | 213(80.93) | 228(82.78) | 220(82.08) | |
COPD, n(%) | 0.17 | |||||
No | 941(86.90) | 235(87.84) | 228(83.20) | 231(84.57) | 247(92.23) | |
Yes | 131(13.10) | 33(12.16) | 39(16.80) | 38(15.43) | 21( 7.77) | |
DM, n(%) | 744(66.16) | 161(55.56) | 168(57.13) | 189(66.52) | 226(84.09) | <0.001 |
Pre-DM, n(%) | 328(33.84) | 107(44.44) | 99(42.87) | 80(33.48) | 42(15.91) | <0.001 |
Quartiles of TyG index | |||||
---|---|---|---|---|---|
Q1(6.80–8.56) | Q2(8.56–8.96) | Q3(8.97–9.40) | Q4(9.40-12.55) | P value | |
HbA1C, %, mean (SD) | 6.06(0.07) | 6.11(0.10) | 6.44(0.08) | 7.52(0.15) | <0.001 |
eGFR, mL/min/1.73m2, mean (SD) | 69.17(1.69) | 74.08(1.74) | 72.56(1.59) | 75.24(1.70) | 0.10 |
LDL-cholesterol, mmol/L, mean (SD) | 2.33(0.07) | 2.62(0.06) | 2.83(0.09) | 2.66(0.09) | < 0.001 |
HDL-cholesterol, mmol/L, mean (SD) | 1.53(0.04) | 1.29(0.03) | 1.20(0.02) | 1.04(0.02) | < 0.001 |
TC, mmol/L, mean (SD) | 4.23(0.08) | 4.50(0.07) | 4.85(0.09) | 5.14(0.10) | < 0.001 |
TG, mmol/L, mean (SD) | 0.80(0.02) | 1.28(0.02) | 1.79(0.03) | 3.40(0.16) | < 0.001 |
Scr, umol/L, mean (SD) | 107.07(6.57) | 92.32(2.65) | 93.91(2.47) | 94.67(2.78) | 0.25 |
LDH, IU/L, mean (SD) | 149.69(3.05) | 141.46(2.69) | 139.17(2.11) | 134.52(2.81) | 0.01 |
Uric acid, umol/L, mean (SD) | 353.11(7.55) | 363.86(6.64) | 375.61(7.85) | 371.84(8.92) | 0.22 |
Albumin, g/L, mean (SD) | 40.98(0.25) | 41.50(0.23) | 41.19(0.24) | 41.18(0.23) | 0.43 |
FINS, pmol/L, mean (SD) | 74.09(4.40) | 106.28(9.51) | 111.25(7.45) | 143.24(9.77) | < 0.001 |
FPG, mmol/L, mean (SD) | 6.10(0.07) | 6.58(0.12) | 7.20(0.12) | 9.75(0.27) | < 0.001 |
Serum potassium, mmol/L, mean (SD) | 4.15(0.04) | 4.14(0.03) | 4.17(0.03) | 4.18(0.03) | 0.67 |
Serum iron, umol/L, mean (SD) | 15.09(0.51) | 15.69(0.47) | 14.95(0.36) | 15.19(0.41) | 0.61 |
Serum sodium, mmol/L, mean (SD) | 139.71(0.23) | 139.46(0.21) | 139.32(0.21) | 138.47(0.28) | 0.01 |
BUN, mmol/L, mean (SD) | 6.67(0.23) | 6.18(0.20) | 6.20(0.21) | 6.69(0.24) | 0.12 |
AST (IU/L) | 27.50(2.36) | 26.02(0.69) | 26.36(1.16) | 25.58(0.58) | 0.79 |
ALT (IU/L) | 22.28(1.04) | 24.62(0.96) | 25.75(1.28) | 27.08(0.80) | 0.004 |
TBil, umol/L, mean (SD) | 13.20(0.45) | 12.96(0.49) | 12.63(0.30) | 12.11(0.39) | 0.31 |
GGT (IU/L) | 29.63(2.08) | 39.31(4.13) | 39.54(5.50) | 43.76(3.35) | 0.001 |
Relationships of TyG index concentration with mortality
Quartiles of TyG index | |||||
---|---|---|---|---|---|
Q1(6.80–8.56) | Q2(8.56–8.96) | Q3(8.96–9.40) | Q4(9.40-12.55) | P trend | |
All-cause mortality | |||||
Number of deaths | 119 | 104 | 122 | 116 | |
Model 1 | 1 | 0.61(0.42,0.89) 0.01 | 0.77(0.57,1.03) 0.08 | 0.76(0.57,1.01) 0.06 | 0.29 |
h(95%CI) P-value | |||||
Model 2 | 1 | 0.66(0.46,0.95) 0.02 | 0.86(0.64,1.17) 0.34 | 1.00(0.75,1.32) 0.99 | 0.46 |
h(95%CI) P-value | |||||
Model 3 | 1 | 0.63(0.44,0.91) 0.01 | 0.84(0.62,1.13) 0.25 | 1.01(0.77,1.32) 0.94 | 0.36 |
h(95%CI) P-value | |||||
CVD mortality | |||||
Number of deaths(%) | 40 | 24 | 47 | 43 | |
Model 1 | 1 | 0.35(0.17,0.73) 0.01 | 0.84(0.50,1.40) 0.05 | 0.88(0.51,1.51) 0.64 | 0.49 |
h(95% CI) P-value | |||||
Model 2 | 1 | 0.37(0.18,0.75) 0.01 | 0.96(0.57,1.62) 0.89 | 1.12(0.65,1.96) 0.68 | 0.14 |
h(95% CI) P-value | |||||
Model 3 | 1 | 0.37(0.18,0.78) 0.01 | 1.13(0.65,1.96) 0.67 | 1.28(0.71,2.30) 0.41 | 0.04 |
h(95% CI) P-value |
The detection of nonlinear relationships
Adjusted HR (95% CI), P-value | |
---|---|
All-cause mortality | |
Total | 1.12(0.92,1.35) 0.25 |
Fitting by two-piecewise Cox proportional risk model | |
Inflection point | 9.05 |
TyG index < 9.05 | 0.47(0.27,0.81) 0.01 |
TyG index ≥ 9.05 | 1.42(1.02,1.99) 0.04 |
P for Log-likelihood ratio | < 0.001 |
CVD mortality | |
Total | 1.53(1.08,2.18) 0.02 |
Fitting by two-piecewise Cox proportional risk model | |
Inflection point | 8.84 |
TyG index < 8.84 | 0.25(0.07,0.89) 0.03 |
TyG index ≥ 8.84 | 1.77(1.08,2.91) 0.02 |
P for Log-likelihood ratio | < 0.001 |
Stratified analyses
All-cause mortality | |||
---|---|---|---|
HR(95% CI) P-value | |||
TyG index | < 9.05 | >=9.05 | p interaction |
Overall | 1 | 1.18(0.95,1.48) 0.13 | |
gender | 0.53 | ||
Female | 1 | 1.26(0.83,1.91) 0.28 | |
Male | 1 | 1.89(1.16,3.07) 0.01 | |
Age, years | 0.12 | ||
< 60 | 1 | 1.29(0.69,2.44) 0.42 | |
>=60 | 1 | 0.98(0.78,1.24) 0.86 | |
BMI, kg/m2, n(%) | 0.99 | ||
<24 | 1 | 0.94(0.56,1.57) 0.82 | |
>=24 | 1 | 1.20(0.95,1.51) 0.13 | |
Race | 0.78 | ||
Black | 1 | 1.51(0.98,2.31) 0.06 | |
Mexican | 1 | 0.93(0.43,2.00) 0.85 | |
Other | 1 | 0.90(0.34, 2.38) 0.83 | |
White | 1 | 1.16(0.89,1.50) 0.27 | |
DM | 0.59 | ||
T2DM | 1 | 1.15(0.90,1.46) 0.27 | |
Pre-dm | 1 | 1.04(0.64,1.64) 0.85 |
CVD mortality | |||
---|---|---|---|
HR(95% CI) P-value | |||
TyG index | < 8.84 | >=8.84 | p interaction |
Overall | 1 | 1.70(1.16,2.50) 0.01 | |
gender | 0.61 | ||
Female | 1 | 1.55(0.77, 3.12) 0.22 | |
Male | 1 | 1.89(1.16,3.07) 0.01 | |
Age, years | 0.39 | ||
< 60 | 1 | 2.12(0.45,9.98) 0.34 | |
>=60 | 1 | 1.18(0.76,1.81) 0.46 | |
BMI, kg/m2, n(%) | 0.14 | ||
<24 | 1 | 0.56(0.17,1.85) 0.34 | |
>=24 | 1 | 2.10(1.30,3.38) 0.002 | |
Race | 0.74 | ||
Black | 1 | 1.91(0.93, 3.93) 0.08 | |
Mexican | 1 | 2.93(0.70,12.23) 0.14 | |
Other | 1 | 9.05(0.69, 118.85) 0.09 | |
White | 1 | 1.59(0.97,2.91) 0.06 | |
DM | 0.31 | ||
T2DM | 1 | 1.33(0.87,2.01) 0.18 | |
Pre-dm | 1 | 2.85(1.28,6.33) 0.01 |