Relationship between methylenetetrahydrofolate reductase (MTHFR) A1298C gene polymorphism and type 2 diabetic nephropathy risk: a meta-analysis

Figures & data

Table 1. General characteristics of the included studies in this meta-analysis.

					Case						Control
Author, Year	Ethnicity	Country	Genotyping methods	Source of control	CC	AC	AA	Total	C	Total (C)	CC	AC	AA	Total	C	Total (C)	HWE (P)
Shpichinetsky, 2000	Caucasian	Israel	PCR-RFLP	Hospital	10	19	26	55	39	110	10	9	24	43	29	86	0
Moczulski, 2003	Caucasian	Poland	PCR-RFLP	Hospital			58	121					68	159
Mtiraoui, 2007	Caucasian	Tunisia	PCR-RFLP	Population	29	140	191	360	198	720	16	128	256	400	160	800	1
Nemr, 2010	Caucasian	Lebanon, Bahrain	PCR-RFLP	Hospital	47	233	196	476	327	952	80	280	277	637	440	1274	0.481
Rahimi, 2010	Caucasian	Iran	PCR-RFLP	Hospital			19	68					41	71
Jafari, 2011	Caucasian	Iran	PCR-RFLP	Hospital				65	34	130				52	76	104
El-Baz, 2012	African	Egypt	PCR-RFLP	Hospital	8	41	53	102	57	204	4	27	69	100	35	200	0.516
Rahimi, 2012	Caucasian	Iran	PCR-RFLP	Hospital				140	104	280				71	82	142

Note: PCR–RFLP: polymerase chain reaction-restriction fragment length polymorphism.

Figure 1. Association of MTHFR A1298C C allele with T2DN susceptibility.

Figure 2. Association of MTHFR A1298C CC genotype with T2DN susceptibility.

Figure 3. Association of MTHFR A1298C AA genotype with T2DN susceptibility.

Table 2. Meta-analysis of the association of MTHFR A1298C gene polymorphism with T2DN risk.

Genetic contrasts	Studies number	Q test p value	Model selected	OR (95% CI)	p
C versus A	6	<0.00001	Random	0.76 (0.43, 1.34)	0.34
CC versus AC+AA	4	0.03	Random	1.18 (0.63, 2.22)	0.60
AA versus AC+CC	6	0.004	Random	0.68 (0.49, 0.96)	0.03
Sensitivity analysis according to HWE
C versus A	3	0.004	Random	1.35 (0.93, 1.95)	0.11
CC versus AC+AA	3	0.01	Random	1.37 (0.61, 3.05)	0.45
AA versus AC+CC	3	0.05	Random	0.70 (0.50, 0.98)	0.04
Sensitivity analysis according to the control source from hospital
C versus A	5	<0.00001	Random	0.65 (0.32, 1.34)	0.24
CC versus AC+AA	3	0.32	Fixed	0.82 (0.59, 1.15)	0.26
AA versus AC+CC	5	0.004	Random	0.68 (0.43, 1.07)	0.09
Sensitivity analysis according to the control source from population
C versus A	1	–	Fixed	1.52 (1.20, 1.93)	0.0006
CC versus AC+AA	1	–	Fixed	2.10 (1.12, 3.94)	0.02
AA versus AC+CC	1	–	Fixed	0.64 (0.48, 0.85)	0.002
Sensitivity analysis according to sample size of case (≥100)
C versus A	3	0.004	Random	1.35 (0.93, 1.95)	0.11
CC versus AC+AA	2	0.007	Random	1.23 (0.45, 3.31)	0.69
AA versus AC+CC	4	0.02	Random	0.78 (0.56, 1.08)	0.14
Sensitivity analysis according to sample size of case (<100)
C versus A	3	<0.00001	Random	0.39 (0.13, 1.15)	0.09
CC versus AC+AA	2	0.20	Fixed	1.11 (0.52, 2.36)	0.78
AA versus AC+CC	2	0.09	Random	0.44 (0.18, 1.08)	0.07