Table 2.

Association between VDR gene SNPs and the risk of GDM

	GDM (n = 826)	Non-GDM (n = 858)	Crude OR (95 % CI)	Crude P	Adjusted OR (95 % CI)	Adjusted P
rs2228570
Codominant model
GG	219	230	1(ref.)		1(ref.)
GA	389	415	0.98(0.78–1.24)	0.89	0.92(0.70–1.21)	0.53
AA	206	203	1.07(0.82–1.39)	0.64	2.40(0.73–1.38)	0.99
Dominant Model
GG	219	230	1(ref.)		1(ref.)
GA + AA	595	618	1.01(0.81–1.26)	0.92	0.94(0.73–1.22)	0.66
Recessive Model
GG + GA	608	645	1(ref.)		1(ref.)
AA	206	203	1.08(0.86–1.35)	0.52	1.06(0.81–1.38)	0.67
Overdominant model
GG + AA	425	433	1(ref.)		1(ref.)
GA	389	415	0.96(0.79–1.16)	0.64	0.92(0.73–1.15)	0.45
rs1544410
Codominant model
CC	752	776	1(ref.)		1(ref.)
CT	63	69	0.94(0.66–1.35)	0.74	0.98(0.65–1.49)	0.92
TT	3	3	1.03(0.21–5.13)	0.97	0.64(0.13–3.19)	0.58
Dominant Model
CC	752	776	1(ref.)		1(ref.)
CT + TT	66	72	0.95(0.67–1.34)	0.76	0.96(0.64–1.43)	0.82
Recessive Model
CC + CT	815	845	1(ref.)		1(ref.)
TT	3	3	1.04(0.21–5.15)	0.97	0.64(0.13–3.20)	0.58
Overdominant model
CC + TT	755	779	1(ref.)		1(ref.)
CT	63	69	0.94(0.66–1.35)	0.74	0.98(0.65–1.49)	0.93
rs739837
Codominant model
GG	414	447	1(ref.)		1(ref.)
GT	324	327	1.07(0.87–1.31)	0.52	1.10(0.86–1.41)	0.44
TT	78	77	1.09(0.78–1.54)	0.61	1.12(0.80–1.66)	0.56
Dominant Model
GG	414	447	1(ref.)		1(ref.)
GT + TT	402	404	1.07(0.89–1.30)	0.46	1.1(0.88–1.39)	0.39
Recessive Model
GG + GT	738	774	1(ref.)		1(ref.)
TT	78	77	1.06(0.76–1.48)	0.72	1.08(0.74–1.57)	0.70
Overdominant model
GG + TT	492	524	1(ref.)		1(ref.)
GT	324	327	1.06(0.87–1.28)	0.59	1.08(0.85–1.37)	0.52
rs731236
Codominant model
AA	745	778	1(ref.)		1(ref.)
GA	68	67	1.06(0.75–1.51)	0.75	1.16(0.77–1.75)	0.48
GG	4	4	1.04(0.26–4.19)	0.95	0.49(0.1–2.21)	0.35
Dominant Model
AA	745	778	1(ref.)		1(ref.)
GA + GG	72	71	1.06(0.75–1.49)	0.74	1.10(0.74–1.64)	0.65
Recessive Model
AA + GA	813	845	1(ref.)		1(ref.)
GG	4	4	1.04(0. 26-4.17)	0.96	0.48(0.1–2.18)	0.34
Overdominant model
AA + GG	749	782	1(ref.)		1(ref.)
GA	68	67	1.06(0.75–1.51)	0.75	1.17(0.77–1.76)	0.47
rs7975232
Codominant model
CC	415	446	1(ref.)		1(ref.)
CA	324	328	1.06(0.87–1.30)	0.57	1.10(0.86–1.40)	0.47
AA	77	74	1.12(0.79–1.58)	0.53	1.19(0.79–1.77)	0.40
Dominant Model
CC	415	446	1(ref.)		1(ref.)
CA + AA	401	402	1.07(0. 88 − 1.30)	0.48	1.11(0.89–1.40)	0.36
Recessive Model
CC + CA	739	774	1(ref.)		1(ref.)
AA	77	74	1.09(0. 78-1.52)	0.61	1.14(0.78–1.68)	0.50
Overdominant model
CC + AA	492	520	1(ref.)		1(ref.)
CA	324	328	1.04(0.86–1.27)	0.67	1.07(0.84–1.35)	0.60

Adjusted OR is adjusted for age, pre-pregnancy BMI, family history of diabetes.

Abbreviations: VDR vitamin D receptor; SNPs single nucleotide polymorphisms; GDM gestational diabetes mellitus; BMI body mass index; OR odds ratio; CI confidence interval; ref reference genotype