Associations between Vascular Endothelial Growth Factor Gene Polymorphisms and Different Types of Diabetic Retinopathy Susceptibility: A Systematic Review and Meta-Analysis

Table 1

Characteristics of studies included in the meta-analysis (NPDR versus DM).

SNPs	Author and reference	Year	Country	Ethnicity	Sample size		Mean age (years)		Male (%)		Duration of diabetes (years)		Genotype		Allele (M/m)		OR (95% CI)			NOS	HWE
					Case	Control	Case	Control	Case	Control	Case	Control	Case	Control	Case	Control	Dominant model	Recessive model	Allelic model
rs2010963 and (G>C)	Khan et al. [11]	2019	Pakistan	Asian	301	573			43.85	47.64			24/34/31	41/47/23	82/96	129/93	0.49 (0.26-0.92)	0.63 (0.34-1.16)	0.62 (0.41-0.92)	6	0.170
	Kamal et al. [12]	2016	Egypt	Caucasian	15	34			53.33	17.65	10 (10-14)	4.5 (2.0-6.5)	7/7/1	8/20/6	21/9	36/32	0.35 (0.09-1.27)	0.33 (0.04-3.05)	0.48 (0.19-1.20)	6	0.292
	Choudhuri et al. [14]	2015	India	Asian	70	102			55.71	53.92			40/26/4	64/34/4	106/34	162/42	1.26 (0.68-2.35)	1.49 (0.36-6.15)	1.24 (0.74-2.07)	6	0.845
	Yuan et al. [22]	2014	China	Asian	124	144			48.39	48.61			46/52/26	49/64/31	144/104	162/126	0.88 (0.53-1.44)	0.97 (0.54-1.74)	0.93 (0.66-1.31)	7	0.244
	Yang et al. [23]	2010	China	Asian	110	109			40.00	55.96			42/53/15	49/55/5	137/83	153/65	1.32 (0.77-2.27)	3.28 (1.15-9.38)	1.43 (0.96-2.12)	6	0.032
	Chun et al. [24]	2010	Korea	Asian	108	134			38.89	38.81			37/52/19	43/69/22	126/90	155/113	0.91 (0.53-1.55)	1.09 (0.55-2.13)	0.98 (0.68-1.41)	7	0.519
	Uthra et al. [25]	2008	Indian	Asian	79	82	—		—	62.20	—		39/33/7	44/29/6	111/47	117/41	1.29 (0.69-2.41)	1.18 (0.38-3.69)	1.21 (0.74-1.98)	6	0.690
	Szaflik et al. [26]	2008	Poland	Caucasian	72	61			43.06	32.79			5/42/23	6/46/6	52/88	58/58	1.50 (0.43-5.19)	4.24 (1.59-11.32)	1.69 (1.03-2.79)	7	<0.001
	Awata et al. [27]	2002	Japan	Asian	80	118			48.75	51.69			14/51/15	47/59/12	79/81	153/83	3.12 (1.57-6.19)	2.04 (0.90-4.63)	1.89 (1.26-2.85)	6	0.295
rs3025039 and (C>T)	Choudhuri et al. [14]	2015	India	Asian	70	102			55.71	53.92			31/34/5	60/33/9	96/44	153/51	1.80 (0.97-3.32)	0.80 (0.26-2.48)	1.38 (0.85-2.22)	6	0.166
	Zhang et al. [28]	2011	China	Asian	80	92			48.75	47.83			55/20/5	46/34/12	130/30	126/58	0.46 (0.24-0.85)	0.44 (0.15-1.32)	0.50 (0.30-0.83)	7	0.167
	Kim et al. [29]	2009	South Korea	Asian	84	277	—	—	—	—	—	—	40/44/0	226/51/0	124/44	503/51	4.88 (2.88-8.24)	—	3.50 (2.24-5.48)	6	0.092
	Uthra et al. [25]	2008	Indian	Asian	86	82	—		—	62.20	—	—	76/10/0	65/17/0	162/10	147/17	0.50 (0.22-1.18)	—	0.53 (0.24-1.20)	6	0.295
	Awata et al. [27]	2002	Japan	Asian	80	118			48.75	51.69			49/27/4	85/31/2	125/35	201/35	1.63 (0.89-2.98)	3.05 (0.55-17.08)	1.61 (0.96-2.70)	6	0.664
rs833061 and (T>C)	Khan et al. [11]	2019	Pakistan	Asian	301	573			43.85	47.64			34/40/18	57/71/65	108/76	185/201	2.09 (1.15-3.79)	1.40 (0.83-2.36)	1.54 (1.08-2.20)	6	<0.001
	Yuan et al. [22]	2014	China	Asian	124	144			48.39	48.61			86/34/4	78/51/15	206/42	207/81	0.52 (0.32-0.86)	0.29 (0.09-0.89)	0.52 (0.34-0.79)	7	0.137
	Szaflik et al. [26]	2008	Poland	Caucasian	72	61			43.06	32.79			3/41/27	3/34/24	47/95	40/82	1.17 (0.23-6.03)	0.95 (0.47-1.91)	0.99 (0.59-1.65)	7	0.039
	Wang et al. [30]	2008	China	Asian	65	75			50.77	45.33			10/36/19	26/33/16	56/74	85/65	2.92 (1.28-6.66)	1.52 (0.71-3.29)	1.73 (1.08-2.78)	7	0.367
rs1570360 and (G>A)	Khan et al. [11]	2019	Pakistan	Asian	301	573			43.85	47.64			37/33/23	98/58/36	107/79	254/130	0.70 (0.39-1.27)	0.63 (0.38-1.05)	0.69 (0.48-0.99)	6	<0.001
	Choudhuri et al. [14]	2015	India	Asian	70	102			55.71	53.92			46/21/3	72/27/3	113/27	171/33	1.25 (0.65-2.40)	1.48 (0.29-7.54)	1.24 (0.71-2.17)	6	0.809
	Chun et al. [24]	2010	Korea	Asian	108	134			38.89	38.81			74/29/5	81/46/7	177/39	208/60	0.70 (0.41-1.20)	0.88 (0.27-2.86)	0.76 (0.49-1.20)	7	0.888
	Awata et al. [27]	2002	Japan	Asian	80	118			48.75	51.69			64/15/1	88/29/1	143/17	205/31	0.73 (0.37-1.46)	1.48 (0.09-24.03)	0.79 (0.42-1.47)	6	0.403
rs699947 and (C>A)	Shahin et al. [31]	2015	Egypt	Caucasian	30	74			0.07	43.24			10/20/0	30/40/4	40/20	100/48	1.36 (0.56-3.32)	0.26 (0.01-4.92)	1.04 (0.55-1.97)	6	0.045
	Chun et al. [24]	2010	Korea	Asian	108	134			38.89	38.81			52/47/9	92/36/6	151/65	220/48	2.36 (1.40-3.99)	1.94 (0.67-5.63)	1.97 (1.29-3.02)	7	0.317

M/m, major/minor allele. Genotype presented as wild type/heterozygous/homozygous; −, not available; SNPs, single nucleotide polymorphisms; OR, odds ratio; 95% CI, 95% confidence interval; NOS, Newcastle–Ottawa quality assessment scale; HWE, Hardy–Weinberg equilibrium.