Aldehyde dehydrogenase 2 rs671G>A polymorphism and ischemic stroke risk in Chinese population: a meta-analysis

Figures & data

Table 1 Scale for quality evaluation

Criteria	Score
Representativeness of cases
Consecutive/randomly selected cases with clearly defined sampling frame	2
Not consecutive/randomly selected case or without clearly defined sampling frame	1
Not described	0
Source of controls
Population-based	2
Hospital-bases or Not described	1
Hardy-Weinberg equilibrium in controls
Hardy-Weinberg equilibrium	2
Hardy-Weinberg disequilibrium	1
Not available	0
Genotyping examination
Genotyping done under “blinded” condition and repeated again	2
Genotyping done under “blinded” condition or repeated again	1
Unblinded done or not mentioned and unrepeated	0
Subjects
Number >500	1
Number <500	0
Association assessment
Assess association between genotypes and ischemic stroke with appropriate statistics and adjustment for confounders	2
Assess association between genotypes and ischemic stroke with appropriate statistics and without adjustment for confounders	1
Inappropriate statistics used	0

Table 2 Characteristics of case-control studies on ALDH2 rs671G>A polymorphism and ischemic stroke risk included in the meta-analysis

First author	Year	Control design	Genotype method	Case	Control	Genotype distribution						P for HWE^a	MAF	NOS evaluation	Adjusted factors
						Case			Control
						GG	GA	AA	GG	GA	AA
Sun HL	2012	HB	PCR-RFLP	78	80	27	44	7	49	28	3	0.68	0.21	7	Age, gender, smoking and alcohol status, total cholesterol, HDLC
Xu XJ	2012	PB	PCR-microarray	100	50	82	16	2	29	19	2	0.61	0.23	8	Age, gender, TC, glucose, LDLC, HDLC, ApoA1, ApoB100l
Zhang CY	2014	NA	PCR- sequencing	53	106	27	24	2	73	32	1	0.21	0.16	6	Age, gender, smoking status, TC, TG, LDL
Zhou Q	2014	PB	PCR- sequencing	117	148	96	19	2	138	10	0	0.67	0.03	8	Age, gender, smoking and alcohol status, BP, DM, heart disease
Wang GY	2014	HB	PCR- sequencing	156	160	80	67	9	110	47	3	0.43	0.17	8	Age, gender, height, weight, BP, DM
Li QY	2015	HB	PCR- sequencing	369	247	619^b		119^c	431^b		63^c	NA	0.13	7	Age, BMI, BP, DM, tobacco habits, alcohol consumption
Sung YF	2016	HB	PCR-APLP	914	746	474	338	102	389	303	54	0.63	0.28	9	Age, BMI, BP, DM, hypercholesterolemia, coronary artery disease, atrial fibrillation, smoking, alcohol drinking and history
Qu Y	2017	PB	PCR- sequencing	394	406	254	120	20	264	128	14	0.75	0.19	9	Age, gender, smoking and alcohol status, DM, TC, TG, LDLC, HDLC, UA
Sun S	2017	HB	MassARRAY	488	503	369	108	11	371	124	8	0.52	0.14	8	Age, gender, smoking and alcohol status, residential region, ethnicity and family history

Notes: ^aHWE in control. ^b: only the G-allele were collected; ^c: only the A-allele were collected.

Abbreviations: NOS, Newcastle-Ottawa scale; HB, hospital based; PB, population based; MAF, minor allele frequency in control group; NA, not available; HDLC, high-density lipoprotein cholesterol; TC, total cholesterol; LDLC, low density lipoprotein cholesterol; ApoA1, apolipoproteinA1; ApoB100, apolipoproteinB100; TG, three acylglycerol; DM, diabetes mellitus; BP, blood pressure; BMI, body mass index; UA, uric acid.

Figure 1 Flow diagram of the study selection process.

Table 3 Summary ORs and 95% CI of ALDH2 rs671G>A polymorphism and ischemic stroke risk

	N*	A vs G				GA vs GG				AA vs GG				GA+AA vs GG				AA vs GG+GA
		OR	95% CI	P	I^2(%)	OR	95% CI	P	I^2(%)	OR	95% CI	P	I^2(%)	OR	95% CI	P	I^2(%)	OR	95% CI	P	I^2(%)
Total	9	1.29	1.01–1.65	0.04	78.2	1.24	0.87–1.76	0.23	81.3	1.68	1.27–2.21	<0.01	11.3	1.31	0.93–1.86	0.13	82.6	1.67	1.27–2.19	<0.01	0
Design
HB	5	1.34	1.03–1.73	0.03	74.0	1.34	0.86–2.09	0.20	83.8	1.71	1.25–2.34	<0.01	18.9	1.42	0.92–2.21	0.11	84.3	1.68	1.24–2.29	<0.01	0.0
PB	3	1.06	0.42–2.67	0.91	88.5	0.93	0.35–2.47	0.88	86.6	1.43	0.76–2.30	0.27	32.2	0.98	0.35–2.70	0.96	88.2	1.41	0.70–2.86	0.24	3.6
NA	1	1.88	1.07–3.31	0.03	NA	2.03	1.02–4.04	0.04	NA	5.41	0.47–62.08	0.18	NA	2.13	1.08–4.19	0.03	NA	4.12	0.36–46.48	0.25	NA
Subjects
<500	5	1.56	0.85–2.87	0.15	83.6	1.59	0.78–3.24	0.21	82.6	3.05	1.14–6.61	0.01	25.2	1.67	0.80–3.49	0.17	84.5	2.45	1.14–5.26	0.02	0
>500	4	1.09	0.98–1.22	0.12	0	0.92	0.79–1.06	0.26	0	1.52	1.13–2.05	0.01	0	0.99	0.86–1.44	0.87	0	1.57	1.17–2.11	<0.01	0
NOS evaluation
NOS ≥8	6	1.14	0.85–1.53	0.39	81.1	1.04	0.73–1.46	0.85	79.4	1.59	1.19–2.11	<0.01	3.7	1.10	0.77–1.56	0.60	81.4	1.60	1.21–2.13	<0.01	0.0
NOS <8	3	1.59	1.24–2.04	<0.01	37.6	2.42	1.50–3.91	<0.01	0	4.49	1.30–15.47	0.02	0	2.54	1.59–4.06	<0.01	0	2.85	0.85–9.54	0.09	0.0

Notes: *Numbers of comparisons. I² for Heterogeneity test.

Abbreviations: HB, hospital based; PB, population based; NA, not available; NOS, Newcastle-Ottawa scale.

Figure 2 OR and 95% CIs of the associations between ALDH2 rs671G>A polymorphism and ischemic stroke risk in AA vs GG model.

Figure 3 Cumulative meta-analyses according to publication year in AA vs GG model of ALDH2 rs671G>A polymorphism.

Figure 4 Sensitivity analysis involving deletion of each study to reflect the influence of the individual dataset to the pooled ORs in AA vs GG model of ALDH2 rs671G>A polymorphism.

Figure 5 Funnel plot analysis to detect publication bias for AA vs GG model of ALDH2 rs671G>A polymorphism. Circles represent the weight of the studies.

Figure S1 OR and 95% CIs of the associations between ALDH2 rs671G>A polymorphism and ischemic stroke risk (A for A vs G model; B for GA vs GG model; C for GA + AA vs GG model; D for AA vs GG + GA model).

Figure S2 Cumulative meta-analyses according to publication year in ALDH2 rs671G>A polymorphism and ischemic stroke risk (A for A vs G model; B for GA vs GG model; C for GA + AA vs GG model; D for AA vs GG + GA model).

Figure S3 Sensitivity analysis through deleting each study to reflect the influence of the individual dataset to the pooled ORs in ALDH2 rs671G>A polymorphism and ischemic stroke risk (A for A vs G model; B for GA vs GG model; C for GA + AA vs GG model; D for AA vs GG + GA model).

Figure S4 Funnel plot analysis to detect publication bias in ALDH2 rs671G>A polymorphism (A for A vs G model; B for GA vs GG model; C for GA + AA vs GG model; D for AA vs GG + GA model). Circles represent the weight of the studies.