Triglyceride-Glucose Index is Related to Carotid Artery Plaque in Railway Workers: A Cross-Sectional Study

Figures & data

Figure 1 Flowchart of the participants’ recruitment.

Table 1 General Characteristics of the Study Participants According to the TyG Index

Characteristics	Overall (N=3169)	TyG index				P value
		Q1	Q2	Q3	Q4
		(N=791)	(N=794)	(N=792)	(N=792)
Sociodemographics
Sex (%)
Male	3137 (98.99)	769 (97.22)	788 (99.24)	790 (99.75)	790 (99.75)	<0.001
Age, years, mean (SD)	49.25 (4.36)	48.90 (4.34)	49.30 (4.37)	49.45 (4.26)	49.34 (4.46)	0.064
≥45 years (%)	2704 (85.33)	666 (84.20)	681 (85.77)	686 (86.62)	671 (84.72)	0.529
Medical history
Diabetes (%)	407 (12.84)	40 (5.06)	77 (9.70)	93 (11.74)	197 (24.87)	<0.001
Hypertension (%)	946 (29.85)	149 (18.84)	221 (27.83)	255 (32.20)	321 (40.53)	<0.001
Hyperlipidemia (%)	1323 (41.75)	131 (16.56)	268 (33.75)	389 (49.12)	535 (67.55)	<0.001
Hypoglycemic agents (%)	233 (7.35)	18 (2.28)	40 (5.04)	46 (5.81)	129 (16.29)	<0.001
Antihypertensive agents (%)	485 (15.30)	73 (9.23)	108 (13.60)	120 (15.15)	184 (23.23)	<0.001
Lipid-lowering drugs (%)	243 (7.67)	26 (3.29)	37 (4.66)	52 (6.57)	128 (16.16)	<0.001
Lifestyle behaviors
Smoking (%)	2106 (66.46)	488 (61.69)	480 (60.45)	554 (69.95)	584 (73.74)	<0.001
Drinking (%)	2093 (66.05)	483 (61.06)	499 (62.85)	528 (66.67)	583 (73.61)	<0.001
Physical activity ≥3000 MET-min/w (%)	1110 (35.03)	301 (38.05)	257 (32.37)	293 (36.99)	259 (32.70)	0.031
Dietary pattern (%)						0.307
Poor diet	49 (1.55)	13 (1.64)	12 (1.51)	8 (1.01)	16 (2.02)
Intermediate diet	1476 (46.58)	350 (44.25)	367 (46.22)	369 (46.59)	390 (49.24)
Ideal diet	1644 (51.88)	428 (54.11)	415 (52.27)	415 (52.40)	386 (48.74)
Salt intake (%)						0.001
Low intakes	570 (17.99)	172 (21.74)	152 (19.14)	117 (14.77)	129 (16.29)
Moderate intakes	2152 (67.91)	523 (66.12)	514 (64.74)	573 (72.35)	542 (68.43)
High intakes	447 (14.11)	96 (12.14)	128 (16.12)	102 (12.88)	121 (15.28)
Clinical variables
BMI, kg/m2, mean (SD)	24.99 (3.05)	23.45 (2.87)	24.75 (2.82)	25.64 (2.97)	26.12 (2.83)	<0.001
SBP, mmHg, mean (SD)	82.71 (11.08)	79.03 (11.04)	81.48 (10.87)	84.24 (10.60)	86.09 (10.50)	<0.001
DBP, mmHg, mean (SD)	124.59 (14.70)	120.11 (14.37)	123.53 (14.75)	125.98 (14.33)	128.71 (13.96)	<0.001
FBG, mmol/L, mean (SD)	5.80 (1.73)	5.10 (0.65)	5.40 (0.83)	5.69 (1.11)	7.01 (2.75)	<0.001
TC, mmol/L, mean (SD)	4.90 (0.92)	4.53 (0.75)	4.82 (0.91)	5.03 (0.87)	5.23 (0.99)	<0.001
TG, mmol/L, mean (SD)	2.37 (2.16)	1.00 (0.22)	1.57 (0.25)	2.24 (0.42)	4.68 (3.24)	<0.001
HDL-C, mmol/L, mean (SD)	1.35 (0.31)	1.54 (0.31)	1.39 (0.27)	1.31 (0.25)	1.14 (0.26)	<0.001
LDL-C, mmol/L, mean (SD)	2.89 (0.66)	2.55 (0.56)	2.86 (0.64)	3.07 (0.64)	3.07 (0.68)	<0.001
hs-CRP, mg/L, mean (SD)	2.15 (4.41)	1.72 (3.17)	2.03 (3.96)	2.51 (6.39)	2.33 (3.33)	0.002
ALT, U/L, mean (SD)	28.74 (22.11)	23.11 (27.62)	27.03 (18.78)	30.70 (19.46)	34.14 (19.89)	<0.001
AST, U/L, mean (SD)	23.68 (12.28)	22.24 (15.32)	22.91 (11.17)	24.02 (10.71)	25.54 (11.10)	<0.001
SUA, mean (SD)	392.58 (82.84)	365.30 (75.28)	384.33 (75.83)	407.12 (81.49)	413.54 (89.19)	<0.001
TyG Index, mean (SD)	9.06 (0.69)	8.28 (0.24)	8.80 (0.12)	9.19 (0.13)	9.97 (0.52)	<0.001
Outcome variables
Hepatic steatosis detected by ultrasound (%)	1641 (51.78)	161 (20.35)	346 (43.58)	506 (63.89)	628 (79.29)	<0.001
MAFLD (%)	1612 (50.87)	148 (18.71)	332 (41.81)	506 (63.89)	626 (79.04)	<0.001
CAP (%)	511 (16.12)	92 (11.63)	112 (14.11)	160 (20.20)	147 (18.56)	<0.001

Notes: Q1: TyG index <8.32, Q2: 8.32≤TyG index<9.19, Q3: 9.19≤TyG index<9.83, Q4 >9.83.

Abbreviations: TyG, triglyceride glucose; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; FBG, fasting blood glucose; TC, total cholesterol; TG, triglyceride; HDL-C, high-density-lipoprotein cholesterol; LDL-C, low-density-lipoprotein cholesterol; hs-CRP, high-sensitivity C-reactive protein; ALT, Alanine aminotransferase; AST, aspartate aminotransferase; SUA, Serum uric acid; MAFLD, metabolic dysfunction-associated fatty liver disease; CAP, carotid artery plaque; Q1-Q4, quartile of TyG index.

Table 2 Association Between the TyG Index and CAP

	OR (95% CI)
	Crude Model	Model 1^a	Model 2^b	Model 3^c
TyG index	1.35 (1.18, 1.54)	1.25 (1.09, 1.43)	1.26 (1.10, 1.46)	1.22 (1.06, 1.41)
Q1	Ref.	Ref.	Ref.	Ref.
Q2	1.25 (0.93, 1.68)	1.17 (0.87, 1.58)	1.20 (0.89, 1.62)	1.22 (0.90, 1.65)
Q3	1.92 (1.46, 2.55)	1.70 (1.28, 2.26)	1.75 (1.31, 2.35)	1.70 (1.27, 2.28)
Q4	1.73 (1.31, 2.30)	1.48 (1.11, 1.98)	1.54 (1.14, 2.08)	1.46 (1.08, 1.98)
P-trend	<0.001	<0.05	<0.05	<0.05

Notes: ^aModel 1: adjusted for age, SBP, DBP. ^bModel 2: adjusted for age, SBP, DBP, BMI. ^cModel 3: adjusted for age, SBP, DBP, BMI, physical activity, smoking, drinking, salt intake, dietary pattern.

Abbreviations: CAP, Carotid artery plaque; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; TyG, Triglyceride glucose; Q1-Q4, quartile of TyG index; Ref, reference.

Figure 2 Multivariate-adjusted association of the TyG index and CAP based on restricted cubic splines. The OR was decreased at the TyG of 9.64; ORs were adjusted for age, SBP, DBP, MAFLD, physical activity, smoking, drinking, salt intake, dietary pattern; the Grey shadow represents 95% CI confidence interval.

Abbreviation: TyG, triglyceride glucose index.

Figure 3 ROC curves for different models in predicting CAP detection. Model 1: adjusted for age, SBP, DBP. Model 2: adjusted for age, SBP, DBP, BMI. Model 3: adjusted for age, SBP, DBP, BMI, physical activity, smoking, drinking, salt intake, dietary pattern.

Table 3 Subgroup Analysis for Association Between the TyG Index and CAP

Subgroup	TyG Index	OR (95% CI)^a	P-Interaction	Subgroup	TyG Index	OR (95% CI)^a	P-Interaction
Age, years				Smoking
<45		1.64 (1.00, 2.66)*	Ref.	No		1.17 (0.80, 1.68)	Ref.
	Q1	Ref.			Q1	Ref.
	Q2	1.93 (0.55, 7.70)			Q2	1.50 (0.77, 2.98)
	Q3	3.63 (1.14, 13.94)*			Q3	2.05 (1.04, 4.15)*
	Q4	3.15 (0.97, 12.35)			Q4	1.10 (0.49, 2.44)
≥45		1.20 (1.03, 1.39)*	0.23	Yes		1.22 (1.04, 1.43)*	0.82
	Q1	Ref.			Q1	Ref.
	Q2	1.19 (0.87, 1.63)			Q2	1.13 (0.80, 1.59)
	Q3	1.62 (1.20, 2.21)*			Q3	1.62 (1.17, 2.24)*
	Q4	1.39 (1.02, 1.91)*			Q4	1.49 (1.07, 2.07)*
Elevated blood pressure				Drinking
No		1.38 (1.13, 1.69)*	Ref.	No		1.17 (0.84, 1.61)	Ref.
	Q1	Ref.			Q1	Reference
	Q2	1.17 (0.79, 1.73)			Q2	1.43 (0.81, 2.59)
	Q3	1.63 (1.12, 2.39)*			Q3	1.96 (1.10, 3.57)*
	Q4	1.62 (1.09, 2.41)*			Q4	1.40 (0.73, 2.71)
Yes		1.15 (0.95, 1.39)	0.33	Yes		1.23 (1.05, 1.45)*	0.77
	Q1	Ref.			Q1	Reference
	Q2	1.24 (0.77, 1.20)			Q2	1.16 (0.81, 1.66)
	Q3	1.87 (1.21, 2.93)*			Q3	1.67 (1.19, 2.35)*
	Q4	1.44 (0.94, 2.26)			Q4	1.46 (1.04, 2.06)*
MAFLD				Physical activity
No		1.50 (1.18, 1.92)*	Ref.	<3000 MET-min/w		1.26 (1.05, 1.51)*	Ref.
	Q1	Ref.			Q1	Ref.
	Q2	1.32 (0.93, 1.89)			Q2	1.34 (0.91, 2.00)
	Q3	1.88 (1.29, 2.74)*			Q3	1.95 (1.33, 2.88)*
	Q4	1.46 (0.90, 2.32)			Q4	1.64 (1.11, 2.44)*
Yes		1.26 (1.04, 1.52)*	0.27	≥3000 MET-min/w		1.17 (0.92, 1.48)	0.63
	Q1	Ref.			Q1	Ref.
	Q2	1.32 (0.72, 2.55)			Q2	1.05 (0.65, 1.71)
	Q3	2.24 (1.29, 4.15)*			Q3	1.45 (0.92, 2.29)
	Q4	2.05 (1.19, 3.78)*			Q4	1.24 (0.77, 2.01)

Notes: ^aAdjusted for age, SBP, DBP, BMI, physical activity, smoking, drinking, salt intake, dietary pattern (except for the one used for stratification, and subgroup of MAFLD was adjusted for age, physical activity, smoking, drinking, salt intake, dietary pattern). *P<0.05.

Abbreviations: CAP, Carotid artery plaque; TyG, Triglyceride glucose; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; MALFD, Metabolic dysfunction-associated fatty liver disease; MET, metabolic equivalent; Q1-Q4, quartile of TyG index; Ref, reference.

Table 4 Sensitivity Analysis for Association Between the TyG Index and CAP After Excluding Participants with Hypertension, Diabetes, Dyslipidemia

	OR (95% CI)^a
	Without Hypertension (N=2223)	Without Diabetes (N=2762)	Without Dyslipidemia (N=1864)
TyG index	1.30 (1.08, 1.57)	1.21 (1.01, 1.44)	1.42 (1.12, 1.78)
Q1	Ref.	Ref.	Ref.
Q2	1.18 (0.81, 1.70)	1.17 (0.84, 1.62)	1.30 (0.90, 1.90)
Q3	1.68 (1.18, 2.41)	1.75 (1.28, 2.40)	1.92 (1.32, 2.82)
Q4	1.49 (1.02, 2.19)	1.33 (0.94, 1.87)	1.66 (1.06, 2.57)
P-trend	<0.05	<0.05	<0.05

Note: ^aAdjusted for age, SBP, DBP, BMI, physical activity, smoking, drinking, salt consumptions, dietary pattern.

Abbreviations: CAP, Carotid artery plaque; TyG, Triglyceride glucose; BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; Q1-Q4, quartile of TyG index; Ref, Reference.