Associations of Thyroid Function Tests with Lipid Levels and Adverse Pregnancy Outcomes During the First Trimester

Figures & data

Table 1 Descriptive Statistics [Mean ± SD or N (%)] of Maternal Characteristics, Thyroid and Lipid Levels in the Study Population (N = 1650)

Parameters	Hypothyroidism	Subclinical Hypothyroidism	Hypothyroxinemia	Hyperthyroidism	Subclinical Hyperthyroidism	Euthyroid	P value
N/%	93/5.6%	43/2.6%	716/43.4%	8/0.5%	6/0.4%	784/47.5%	/
Mean TSH(uIU/mL)	4.9±1.9	4.8±1.7	1.8±0.8	0.02±0.01	0.02±0.01	1.4±0.9	0.000
Mean FT4(Pmol/L)	9.1±1.6	14.0±1.8	10.1±0.9	44.5±31.2	14.6±2.1	14.4±2.0	0.000
Mean FT3(Pmol/L)	3.6±1.0	4.0±0.7	3.8±0.5	12.3±9.9	4.5±0.5	4.1±0.6	0.000
Mean TPOAb(IU/mL)	47.6±108.8	72.8±141.9	23.7±58.9	32.1±43.9	32.3±57.9	23.8±55.9	0.000
Age(y)	30.1± 4.1	28.9± 4.3	30.7± 4.4	28.8± 3.4	27.2± 3.1	29.8± 4.0	0.000
Gravidity(n)	2.3± 1.3	2.1± 1.4	2.4± 1.3	2.3± 1.4	2.3± 1.0	2.1± 1.2	0.001
Parity(n)	1.6± 0.6	1.5± 0.8	1.6± 0.6	1.6±0.7	1.5± 0.5	1.5± 0.6	0.000
Fetal birth weight (g)	3438.2± 407.3	3211.4± 401.6	3317.4± 421.8	3353.3± 577.4	3336.7±499.2	3288.7± 440.6	0.027
Triglyceride (mmol/L)	1.6±0.8	1.4±0.6	1.5±0.6	1.3±0.2	1.5±0.3	1.3±0.5	0.000
Total cholesterol(mmol/L)	5.0±0.8	4.5±0.6	4.8±0.8	4.3±0.4	5.1±0.8	4.7±0.7	0.000
High-density lipoprotein(mmol/L)	1.7±0.3	1.6±0.3	1.7±0.4	1.4±0.1	1.9±0.3	1.7±0.3	0.000
Low-density lipoprotein(mmol/L)	2.4±0.6	2.2±0.5	2.4±0.7	2.2±0.4	2.5±1.0	2.3±0.6	0.000
Apolipoprotein A1(g/L)	1.8±0.2	1.6±0.3	1.8±0.3	1.5±0.1	2.0±0.1	1.7±0.3	0.010
Apolipoprotein B(g/L)	0.8±0.2	0.7±0.2	0.8±0.2	0.7±0.1	0.8±0.3	0.7±0.2	0.000
Apolipoprotein E(g/L)	22.7±12.0	21.4±11.5	21.8±12.0	13.0±6.7	21.8±5.6	19.6±10.4	0.001

Abbreviations: TSH, thyroid-stimulating hormone; FT4, free thyroxine; FT3, free triiodothyronine; TPOAb, thyroid peroxidase antibody.

Table 2 The Chi-Square Test or Fisher’s Exact Test for Adverse Pregnancy Outcomes According to Thyroid Function in the First Trimester

Outcomes and Complications	Hypothyroidism	Subclinical Hypothyroidism	Hypothyroxinemia	Hyperthyroidism	Subclinical Hyperthyroidism	Euthyroid	P value
Gestational diabetes mellitus	9(9.7)	11(25.6)	174(24.3)^a	1(12.5)	0(0)	134(17.1)	0.001
Caesarean section	61(65.6)^a	26(60.5)	436(60.9)^a	5(62.5)	2(33.3)	409(52.1)	0.004
Pregnancy-induced hypertension	3(3.2)	2(4.7)	36(5)^a	1(12.5)	0(0)	22(2.8)	0.141
Preeclampsia	1(1.1)	0(0)	28(3.9)^a	1(12.5)	0(0)	16(2.0)	0.084
Preterm birth	0(0)^a	2(4.7)	51(7.1)	1(12.5)	1(16.7)	58(7.4)	0.018
Low birth weight	1(1.1)	2(4.7)	23(3.3)	1(16.7)	1(16.7)	27(3.5)	0.115
Macrosomia	7(7.5)	1(2.3)	36(5)	1(12.5)	0(0)	42(5.4)	0.592
Fetal distress	5(5.4)	1(2.3)	25(3.5)	0(0)	0(0)	19(2.4)	0.521
Polyhydramnios	5(5.4)^a	0(0)	4(0.6)	0(0)	0(0)	1(0.1)	0.001
Postpartum hemorrhage	6(6.5)	0(0)	32(4.5)	1(12.5)	0(0)	37(4.7)	0.403
Hypertriglyceridemia	19(20.4)^a	7(16.3)	141(19.7)^a	0(0)	1(16.7)	91(11.6)	0.001

Notes: ^aP<0.05 vs. the euthyroid group. Data are presented as number (percentage).

Table 3 Odds Ratios Calculated from Logistic Regression Analysis for Thyroid Hormone Dysfunction and Lipid Levels

Parameters	Hypothyroidism		Subclinical Hypothyroidism		Hypothyroxinemia
	AOR (95% CI)	p value	AOR (95% CI)	p value	AOR (95% CI)	P value
Triglyceride	1.5 (0.87–2.72)	0.141	2.36(1.00–5.61)	0.051	2.06(1.50–2.82)	0.000
Total cholesterol	1.81 (0.45–7.27)	0.400	0.06(0.01–0.55)	0.013	0.46(0.24–0.87)	0.017
High-density lipoprotein	2.08 (0.38–11.46)	0.401	7.05(0.47–106.3)	0.158	4.36(1.91–9.96)	0.000
Low-density lipoprotein	0.4 (0.09–1.79)	0.230	19.16(1.62–226.4)	0.019	1.86(0.91–3.81)	0.091
Apolipoprotein A1	0.20 (0.06–0.69)	0.011	0.94(0.11–7.93)	0.952	0.45(0.22–0.88)	0.021
Apolipoprotein B	16.89 (1.54–185.93)	0.021	0.08(0.00–4.63)	0.226	2.26(0.56–9.21)	0.255
Apolipoprotein E	1.00(0.98–1.03)	0.844	1.03(1.00–1.06)	0.118	1.01(0.99–1.02)	0.367

Note: ORs were adjusted for maternal age, gravidity and parity.

Abbreviations: AOR, adjusted odds ratio; CI, confidence interval.

Table 4 Characteristics of the Study Participants Divided by First-Trimester TSH, FT4, FT3, TPOAb, FT3/FT4 Ratio Concentration

Parameters	TSH		FT4		FT3		TPOAb		FT3/FT4
	β	P	β	P	β	P	β	P	β	P
Age	0.011	0.651	−0.067	0.009	−0.039	0.153	0.037	0.155	0.038	0.141
Gravidity	0.028	0.275	−0.024	0.384	−0.087	0.001	−0.018	0.486	0.034	0.187
Parity	−0.021	0.409	0.021	0.408	0.104	0.000	−0.002	0.944	0.01	0.694
Triglyceride	0.038	0.150	−0.041	0.123	−0.004	0.917	0.000	0.992	0.046	0.083
Total cholesterol	0.077	0.002	−0.067	0.009	−0.027	0.344	0.011	0.687	0.074	0.003
High-density lipoprotein	0.015	0.611	0.023	0.428	−0.026	0.488	0.005	0.844	0.026	0.372
Low-density lipoprotein	−0.082	0.080	−0.006	0.898	−0.007	0.796	0.010	0.698	−0.04	0.393
Apolipoprotein A1	−0.013	0.642	0.025	0.386	−0.077	0.003	0.007	0.789	−0.009	0.754
Apolipoprotein B	−0.030	0.429	−0.031	0.406	−0.032	0.232	0.020	0.459	−0.008	0.835
Apolipoprotein E	0.050	0.054	0.011	0.687	−0.005	0.853	−0.001	0.963	0.031	0.239
Caesarean section	0.042	0.098	−0.027	0.298	0.020	0.428	0.011	0.670	0.072	0.004
Preterm birth	−0.065	0.009	0.014	0.572	0.038	0.128	0.018	0.483	0.015	0.547
Gestational diabetes mellitus	−0.012	0.635	0.056	0.026	0.065	0.010	0.023	0.369	0.003	0.903
Polyhydramnios	0.046	0.064	−0.016	0.535	−0.022	0.386	0.051	0.047	0.031	0.219
Hypertriglyceridemia	0.013	0.608	−0.027	0.293	−0.051	0.046	−0.061	0.018	0.008	0.746

Note: The bold values are statistically significant results.

Abbreviations: TSH, thyroid-stimulating hormone; FT4, free thyroxine; FT3, free triiodothyronine; TPOAb, thyroid peroxidase antibody.