Comparison of triglyceride-glucose index and its derived indices as markers for adverse pregnancy outcomes

Table 1 Anthropometric and biochemical characteristics of participants categorized by tertiles of triglyceride-glucose index, n (%)

Characteristics	Overall	TyG index tertiles			P value
		T1	T2	T3
	(n = 10422)	(n = 3475)	(n = 3473)	(n = 3474)
Maternal age (years)	30.0 ± 3.3	29.6 ± 3.1	30.0 ± 3.2	30.5 ± 3.5	< 0.001
Pre-pregnancy BMI (kg/m2)	21.4 ± 2.7	20.5 ± 2.3	21.3 ± 2.6	22.2 ± 3.0	< 0.001
Gravidity					< 0.001
1	6047 (58.0)	2253 (64.8)	2011 (57.9)	1783 (51.3)
≥ 2	2697 (25.9)	795 (22.9)	928 (26.7)	974 (28.0)
Parity					< 0.001
1	8109 (77.8)	2896 (83.3)	2737 (78.8)	2476 (71.3)
≥ 2	2164 (20.8)	537 (15.5)	705 (20.3)	922 (26.5)
SBP (mmHg)	111.2 ± 10.6	109.5 ± 10.6	111.1 ± 10.5	112.9 ± 10.6	< 0.001
DBP (mmHg)	69.8 ± 7.6	68.5 ± 7.4	69.7 ± 7.5	71.3 ± 7.7	< 0.001
Waist circumference (cm)	88.4 ± 6.2	86.7 ± 5.7	88.2 ± 6.0	90.2 ± 6.4	< 0.001
Waist-to-height ratio	0.6 ± 0.0	0.5 ± 0.0	0.5 ± 0.0	0.6 ± 0.0	< 0.001
OGTT-0 hour (mmol/L)	4.5 ± 0.3	4.4 ± 0.3	4.4 ± 0.3	4.6 ± 0.4	< 0.001
OGTT-1 hour (mmol/L)	7.8 ± 1.6	7.5 ± 1.6	7.7 ± 1.6	8.0 ± 1.6	< 0.001
OGTT-2 hour (mmol/L)	6.7 ± 1.3	6.4 ± 1.3	6.7 ± 1.3	6.9 ± 1.3	< 0.001
ALT (U/L)	16.8 (11.8, 25.4)	18.7 (12.8, 28.7)	17.2 (12.0, 25.8)	14.8 (10.7, 21.8)	< 0.001
AST (U/L)	18.5 (15.6, 22.7)	19.6 (16.5, 24.3)	18.7 (15.9, 22.8)	17.4 (14.8, 21.0)	< 0.001
TP (g/L)	65.7 ± 3.3	64.8 ± 3.2	65.6 ± 3.2	66.5 ± 3.3	< 0.001
ALB (g/L)	39.4 ± 2.4	39.3 ± 2.3	39.4 ± 2.4	39.5 ± 2.4	0.002
UREA (mmol/L)	3.0 ± 0.7	3.2 ± 0.7	3.0 ± 0.7	2.9 ± 0.7	< 0.001
CREA (μmol/L)	39.8 ± 6.2	39.9 ± 6.1	40.0 ± 6.2	39.5 ± 6.2	0.001
UA (μmol/L)	231.3 ± 47.3	224.3 ± 45.2	229.5 ± 46.5	240.1 ± 48.9	< 0.001
TC (mmol/L)	6.0 ± 1.0	5.8 ± 0.8	6.1 ± 0.9	6.2 ± 1.0	< 0.001
TG (mmol/L)	1.9 (1.6, 2.4)	1.4 (1.3, 1.6)	1.9 (1.8, 2.1)	2.7 (2.4, 3.1)	< 0.001
HDL-C (mmol/L)	2.3 ± 0.4	2.5 ± 0.4	2.3 ± 0.4	2.2 ± 0.4	< 0.001
LDL-C (mmol/L)	3.0 ± 0.7	2.9 ± 0.6	3.1 ± 0.7	3.2 ± 0.8	< 0.001
HbA1c (%)	4.9 ± 0.2	4.9 ± 0.2	4.9 ± 0.2	5.0 ± 0.2	< 0.001
TyG	8.8 (8.6, 9.1)	8.5 (8.4, 8.6)	8.8 (8.8, 8.9)	9.2 (9.1, 9.3)	< 0.001
TyG-BMI	205.5 (188.8, 225.9)	190.9 (178.5, 205.4)	206.2 (191.0, 223.0)	223.4 (205.7, 243.9)	< 0.001
TyG-WC	783.4 ± 69.8	735.6 ± 52.1	780.4 ± 54.0	833.4 ± 64.3	< 0.001
TyG-WHtR	4.8 ± 0.4	4.5 ± 0.3	4.8 ± 0.3	5.2 ± 0.4	< 0.001

TyG: Triglyceride-glucose index; T: Tertiles; BMI: Body mass index; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; OGTT: Oral glucose tolerance test; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; TP: Total protein; ALB: Albumin; UREA: Urea; CREA: Creatinine; UA: Uric acid; TC: Total cholesterol; TG: Triglycerides; HDL-C: High-density lipoprotein cholesterol; LDL-C: Low-density lipoprotein cholesterol; HbA1c: Glycated hemoglobin; WC: Waist circumference; WHtR: Waist-to-height ratio.

Table 2 Association of triglyceride-glucose index and its derived indices with adverse pregnancy outcomes

Outcomes	Model	Tertile	OR (95%CI)
			TyG	TyG-BMI	TyG-WC	TyG-WHtR
GDM	Model 1	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.55 (1.34-1.79)	1.32 (1.15-1.53)	1.34 (1.14-1.56)	1.43 (1.23-1.68)
		T3	2.44 (2.12-2.79)	2.08 (1.82-2.38)	2.25 (1.94-2.60)	2.40 (2.07-2.77)
		P for trend	< 0.001	< 0.001	< 0.001	< 0.001
	Model 2	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.41 (1.22-1.63)	1.22 (1.05-1.41)	1.21 (1.03-1.42)	1.30 (1.10-1.53)
		T3	2.00 (1.73-2.31)	1.70 (1.47-1.96)	1.75 (1.46-2.10)	1.93 (1.61-2.31)
		P for trend	< 0.001	< 0.001	< 0.001	< 0.001
	Model 3	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.40 (1.20-1.64)	1.07 (0.92-1.24)	1.14 (0.97-1.35)	1.28 (1.08-1.51)
		T3	1.90 (1.62-2.24)	1.20 (1.02-1.41)	1.50 (1.24-1.82)	1.69 (1.40-2.04)
		P for trend	< 0.001	0.021	< 0.001	< 0.001
HDP	Model 1	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.39 (1.12-1.73)	1.45 (1.14-1.84)	1.40 (1.10-1.79)	1.41 (1.11-1.79)
		T3	2.26 (1.85-2.77)	3.49 (2.83-4.31)	2.97 (2.38-3.69)	2.77 (2.23-3.44)
		P for trend	< 0.001	< 0.001	< 0.001	< 0.001
	Model 2	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.06 (0.84-1.33)	1.24 (0.97-1.58)	1.09 (0.84-1.41)	1.07 (0.82-1.38)
		T3	1.35 (1.08-1.67)	2.01 (1.61-2.52)	1.29 (0.98-1.71)	1.27 (0.96-1.67)
		P for trend	0.004	< 0.001	0.058	0.076
	Model 3	T1	Ref.	Ref.	Ref.	Ref.
		T2	0.99 (0.78-1.25)	1.10 (0.86-1.42)	1.03 (0.79-1.33)	1.02 (0.79-1.33)
		T3	1.16 (0.91-1.49)	1.46 (1.14-1.87)	1.13 (0.85-1.51)	1.13 (0.85-1.51)
		P for trend	0.166	0.001	0.371	0.368
CD	Model 1	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.14 (1.03-1.26)	1.28 (1.15-1.42)	1.28 (1.15-1.44)	1.41 (1.25-1.58)
		T3	1.43 (1.30-1.59)	2.01 (1.82-2.23)	1.95 (1.75-2.17)	2.38 (2.13-2.65)
		P for trend	< 0.001	< 0.001	< 0.001	< 0.001
	Model 2	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.00 (0.90-1.11)	1.18 (1.06-1.32)	1.10 (0.97-1.24)	1.23 (1.09-1.39)
		T3	1.10 (0.99-1.23)	1.71 (1.54-1.91)	1.31 (1.13-1.50)	1.78 (1.55-2.05)
		P for trend	0.077	< 0.001	< 0.001	< 0.001
	Model 3	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.00 (0.89-1.11)	1.16 (1.04-1.30)	1.08 (0.96-1.22)	1.21 (1.07-1.37)
		T3	1.08 (0.95-1.22)	1.63 (1.45-1.84)	1.27 (1.10-1.46)	1.73 (1.50-2.00)
		P for trend	0.215	< 0.001	0.001	< 0.001
LGA	Model 1	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.33 (1.14-1.54)	1.88 (1.59-2.22)	1.96 (1.63-2.34)	1.73 (1.46-2.06)
		T3	1.82 (1.58-2.10)	3.62 (3.10-4.24)	3.52 (2.98-4.16)	2.85 (2.43-3.35)
		P for trend	< 0.001	< 0.001	< 0.001	< 0.001
	Model 2	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.18 (1.01-1.37)	1.83 (1.54-2.16)	1.76 (1.47-2.12)	1.50 (1.25-1.79)
		T3	1.41 (1.21-1.64)	3.48 (2.95-4.09)	2.69 (2.20-3.28)	1.96 (1.61-2.38)
		P for trend	< 0.001	< 0.001	< 0.001	< 0.001
	Model 3	T1	Ref.	Ref.	Ref.	Ref.
		T2	1.16 (1.00-1.36)	1.79 (1.51-2.12)	1.75 (1.45-2.11)	1.45 (1.21-1.73)
		T3	1.39 (1.17-1.64)	3.28 (2.75-3.91)	2.63 (2.14-3.23)	1.83 (1.50-2.24)
		P for trend	< 0.001	< 0.001	< 0.001	< 0.001

Model 1: Unadjusted raw data. Model 2: Model 1 adjusted for age, pre-pregnancy body mass index, gravidity (once or twice plus), parity (primiparous or not), systolic blood pressure, and diastolic blood pressure. Model 3: Model 2 adjusted for alanine aminotransferase, aspartate aminotransferase, total protein, albumin, urea, creatinine, uric acid, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and glycated hemoglobin. T: Tertiles; OR: Odds ratio; CI: Confidence interval; TyG: Triglyceride-glucose index; GDM: Gestational diabetes mellitus; HDP: Hypertensive disorders of pregnancy; CD: Cesarean delivery; LGA: Large for gestational age; BMI: Body mass index; WC: Waist circumference; WHtR: Waist-to-height ratio.

Table 3 Comparative analysis of triglyceride-glucose index and its derived indices for predicting adverse pregnancy outcomes

	AUC (95%CI)	P value	IDI	P value	cNRI	P value
GDM
TyG	0.611 (0.596-0.626)	< 0.001	Ref.		Reference
TyG-BMI	0.594 (0.579-0.609)	< 0.001	-0.006	< 0.001	-0.107	< 0.001
TyG-WC	0.613 (0.596-0.629)	< 0.001	0.001	0.440	0.035	0.232
TyG-WHtR	0.615 (0.598-0.631)	< 0.001	0.003	0.036	0.064	0.030
HDP
TyG	0.606 (0.584-0.628)	< 0.001	Ref.		Reference
TyG-BMI	0.667 (0.645-0.688)	< 0.001	0.021	< 0.001	0.291	< 0.001
TyG-WC	0.644 (0.620-0.668)	< 0.001	0.012	< 0.001	0.273	< 0.001
TyG-WHtR	0.639 (0.616-0.663)	< 0.001	0.010	< 0.001	0.200	< 0.001
CD
TyG	0.549 (0.538-0.561)	< 0.001	Ref.		Reference
TyG-BMI	0.593 (0.581-0.604)	< 0.001	0.018	< 0.001	0.210	< 0.001
TyG-WC	0.588 (0.575-0.600)	< 0.001	0.015	< 0.001	0.217	< 0.001
TyG-WHtR	0.607 (0.595-0.620)	< 0.001	0.025	< 0.001	0.305	< 0.001
LGA
TyG	0.581 (0.565-0.597)	< 0.001	Ref.		Reference
TyG-BMI	0.656 (0.641-0.671)	< 0.001	0.028	< 0.001	0.377	< 0.001
TyG-WC	0.657 (0.641-0.673)	< 0.001	0.031	< 0.001	0.456	< 0.001
TyG-WHtR	0.627 (0.611-0.644)	< 0.001	0.017	< 0.001	0.291	< 0.001

CI: Confidence interval; GDM: Gestational diabetes mellitus; HDP: Hypertensive disorders of pregnancy; CD: Cesarean delivery; LGA: Large for gestational age; IDI: Integrated discrimination improvement; AUC: Areas under the curve; cNRI: Continuous net reclassification improvement.