The Association Between the Imbalance of Single-Carbon Nutrients in Early Pregnancy and Gestational Diabetes Mellitus Risk is Influenced by Serum Selenium Status: A Cohort Study

Figures & data

Figure 1 Participants flowchart.

Table 1 Maternal Characteristics in the GDM and Non-GDM Groups

Maternal Characteristics	GDM (n=67)	Non-GDM (n=299)	P
Age (years)	30.5±4.0	28.9±3.5	0.001
< 30	30 (44.8)	122 (40.8)	0.551
≥30	37 (55.2)	177 (59.2)
Height (cm)	161.5±4.4	161.4±5.0	0.973
Weight (kg)	64.3±11.5	58.4±10.4	<0.001
BMI at enrollment (kg/m^2)	24.3±3.6	22.4±3.6	<0.001
< 24	37 (55.2)	216 (72.2)	0.006
≥24	30 (44.8)	83 (27.8)
Parity
Primiparous	37 (55.2)	180 (60.2)	0.454
Multiparous	30 (44.8)	119 (39.8)
Family history of diabetes	12 (17.9)	21 (7.0)	0.005
Physical activity
0–150 minutes per week	45 (67.2)	149 (49.8)	0.01
≥ 150 minutes per week	22 (32.8)	150 (50.2)
Folic acid supplements at enrollment
< 400μg	24 (35.8)	97 (32.4)	0.595
≥400μg	43 (64.2)	202 (67.6)
Hemoglobin (g/L)	132.4 (8.9)	131.3 (10.8)	0.448
Ferritin (ng/mL)	52.6±41.0	51.1±34.4	0.770
Serum folate (nmol/L)	23.9 (14.1–24.0)	21.4 (16.0–24.0)	0.454
C-reactive protein (mg/L)	3.3 (1.6–5.9)	1.9 (0.9–3.5)	<0.001
Serum homocysteine (μmol/L)	9.1±1.9	9.1±2.8	0.978
Serum vitamin B12 (pmol/L)	237.3±101.8	241.0±108.9	0.801
RBC folate (nmol/L)	755.1±276.0	690.6±258.3	0.069
RBC folate/vitamin B12	2.35 (1.71–3.18)	2.15 (1.52–2.89)	0.166
Serum selenium (μg/L)	70.3±16.2	67.0±13.4	0.083
25(OH) D (nmol/L)	20.0±5.3	18.5±6.3	0.067
Fasting glucose (mmol/L)	4.8±0.5	4.4±0.4	<0.001
Total cholesterol (mmol/L)	4.25±0.74	4.17±0.68	0.453
Triglycerides (mmol/L)	1.10 (0.89–1.47)	0.90 (0.71–1.15)	0.001
HDL cholesterol (mmol/L)	1.47±0.24	1.56±0.28	0.024
LDL cholesterol (mmol/L)	2.12±0.61	1.96±0.53	0.027

Note: Continuous variables are presented as mean±SD or median (interquartile range, 25–75%) when appropriate, while categorical variables are presented as n (%).

Abbreviations: RBC, red blood cell; HDL, high density lipoprotein; LDL, low density lipoprotein; 25(OH)D, 25-hydroxy vitamin D.

Table 2 Associations of GDM Risk with RBC Folate/Vitamin B12 Ratios in Overall Study Population

RBC Folate/Vitamin B12 Ratio	GDM, n (%)	Model One*		Model Two^#
		OR (95% CI)	P	OR (95% CI)	P
T1 (0.47–1.79)	18 (15.0)	Reference	–	Reference	–
T2 (1.80–2.65)	20 (16.3)	1.12 (0.57–2.20)	0.751	1.05 (0.48–2.29)	0.912
T3 (≥ 2.66)	29 (23.8)	1.66 (0.87–3.15)	0.124	1.57 (0.72–3.43)	0.255
As a continuous variable	–	1.19 (0.98–1.43)	0.080	1.18 (0.93–1.49)	0.174

Notes: *Without adjustment for covariates. ^#Adjusted for age, BMI (at enrollment), education level, physical activity, parity status, family history of diabetes, FA supplement use, lipid profiles, CRP, ferritin, Hcy, hemoglobin, vitamin D status, and serum selenium.

Table 3 Associations Between the RBC Folate/Vitamin B12 Ratios and GDM in Women with Normal Serum Selenium or Selenium Deficiency

	Selenium Deficiency (< 70.0 μg/L)			Normal Serum Selenium (≥70.0 μg/L)
	n	OR (95% CI)*	P	n	OR (95% CI)*	P
RBC folate/vitamin B12
T1(0.47-1.79)	71	Reference	–	49	Reference	–
T2 (1.80-2.65)	82	1.91(0.61–5.97)	0.263	41	0.63(0.17–2.41)	0.502
T3 (≥ 2.66)	92	3.40(1.16–9.97)	0.026	31	0.60(0.14–2.69)	0.507

Note: *Adjusted for age, BMI (at enrollment), education level, physical activity, parity status, family history of diabetes, FA supplement use, lipid profiles, CRP, ferritin, Hcy, hemoglobin, and vitamin D status.

Table 4 Associations Between the RBC Folate/Vitamin B12 Ratios and GDM in Women with or without Serum Vitamin D Deficiency

	25(OH)D (<20 nmol/L)			25(OH)D (≥20nmol/L)
	n	OR (95% CI)*	P	n	OR (95% CI) *	P
RBC folate/vitamin B12
T1 (0.47–1.79)	75	Reference	–	45	Reference	–
T2 (1.80–2.65)	71	0.64 (0.20–2.12)	0.469	52	1.72 (0.49–5.97)	0.397
T3 (≥ 2.66)	55	1.18 (0.36–3.69)	0.806	68	2.21 (0.61–8.03)	0.229

Note: *Adjusted for age, BMI (at enrollment), education level, physical activity, parity status, family history of diabetes, FA supplement use, lipid profiles, CRP, ferritin, Hcy, hemoglobin, and serum selenium levels.