Relationship between apolipoprotein E gene polymorphism and total cholesterol level in patients with kidney diseases

Table 1 The detailed characteristics of included studies

Author	Study type	Location of study	Ethnicity	Patient type	Number of subjects	Comparisons of apoE gene polymorphism	Genotyping method reported	Blinding of genotyping
Feussner et al[26]	Prospective	Germany	Caucasian	ESRD	141 males and 104 females	E2E2, E2E3, E2E4, E3E3, E3E4, E4E4	No	Not mention
Eggertsen et al[29]	Prospective	Sweden	Caucasian	ESRD: 19 cases glomerulonephritis, 11 cases diabetic nephropathy, nine cases interstitial nephritis	25 males and 26 females	E2E3, E2E4, E3E3, E3E4, E4E4	Yes	Not mention
Oda et al[28]	Prospective	Japan	Asian	107 with GN and 399 with ESRD	Patients with GN consisted of 42 men and 65 women	E2E3, E3E3, E3E4, ε2, ε3, ε4	Yes	Not mention
Lim et al[38]	Prospective	China	Asian	ESRD: 85 patients with chronic GN, 30 patients with DN, 18 patients with chronic pyelonephritis, 3 patients with PKD	96 males and 60 females	ε4, non-ε4	Yes	Not mention
Kimura et al[39]	Prospective	Japan	Asian	DN	88 men and 90 women	ε4, non-ε4	Yes	Not mention
Werle et al[30]	Prospective	Germany	Caucasian	DN	159 men and 129 women	E2E3, E3E3, ε2, ε3, ε4	Yes	Not mention
Imura et al[31]	Prospective	Japan	Asian	ESRD	287 men and 206 women	E2E3, E3E3, E3E4, ε2, ε3, ε4	Yes	Not mention
Xiang et al[43]	Prospective	China	Asian	DN	26 men and 20 women	ε2, ε3	Yes	Not mention
Güz et al[32]	Prospective	Turkey	Caucasian	ESRD: GN (107 cases), hypertension nephropathy (37 cases), unknown (36 cases), pyelonephritis (29 cases), amyloidosis (20 cases), DN (15 cases), obstructive uropathy (9 cases), PKD (7 cases), toxic nephropathy (6 cases), and Alport’s syndrome (3 cases)	149 men and 112 women	E2E3, E3E3, E3E4, ε2, ε3, ε4	Yes	Not mention
Zahálková et al[34]	Prospective	Czech	Caucasian	ESRD	53 males and 34 females	E2E3, E3E3, E3E4, ε2, ε3, ε4	Yes	Not mention
Lehtinen et al[40]	Prospective	Finland	Caucasian	DN	Not mention	ε4, non-ε4	Yes	Not mention
Kahraman et al[42]	Prospective	Turkey	Caucasian	Renal transplant recipients	80 males and 38 females	ε2, ε3, ε4	Yes	Not mention
Joss et al[36]	Prospective	United Kingdom	Caucasian	DN	Not mention	E2E3, E3E3, E3E4, ε2, ε3, ε4	Yes	Not mention
Maluf et al[45]	Prospective	United States	Mix	Renal transplant recipients	21 males and 18 females	ε2, ε3, ε4	Yes	Not mention
Arikan et al[35]	Prospective	Turkey	Caucasian	ESRD	84 males and 60 females	E2E3, E3E3, E3E4, ε2, ε3, ε4	Yes	Not mention
Kwon et al[41]	Retrospective	Korea	Asian	DN	32 males and 62 females	ε2, ε3, ε4	No	Not mention
Leiva et al[46]	Retrospective	Chile	South America	DN	53 males and 32 females	ε3, ε4	Yes	Not mention
Ma et al[37]	Prospective	China	Asian	DN	146 males and 259 females	ε2, non-ε2	Yes	Not mention
Erdogan et al[33]	Prospective	Turkey	Caucasian	DN	19 males and 27 females	E2E3, E3E3, E3E4, ε2, ε3, ε4	Yes	Not mention
Hu et al[27]	Prospective	China	Asian	MCNS	176 males and 74 females	E2E2, E2E3, E2E4, E3E3, E3E4, E4E4, ε2, ε3, ε4	Yes	Not mention
Li et al[44]	Prospective	China	Asian	Renal transplant recipients	59 males and 46 females	ε2, ε3, ε4	Yes	Not mention

ESRD: End-stage renal disease; GN: Glomerulonephritis; DN: Diabetic nephropathy; PKD: Polycystic kidney disease; MCNS: Minimal change nephrotic syndrome.

Table 2 Meta-analysis of the association of apoE gene polymorphism with total cholecterol level

Genetic comparisons	Q test	P contrasts	Model seclected	Weighted mean differences (95%CI)	P value
E2E2 vs E3E3	1	-	Fixed	109.00 (-32.07-250.07)	0.13
E2E3 vs E3E3	13	< 0.00001	Random	-1.93 (-3.39--0.46)	0.01
E2E4 vs E3E3	3	0.48	Random	-2.48 (-4.23--0.72)	0.006
E3E4 vs E3E3	13	< 0.00001	Random	2.14 (0.46-3.83)	0.01
E4E4 vs E3E3	3	0.02	Random	0.30 (-4.25-4.84)	0.90
ε2 vs non-ε2	2	0.57	Fixed	-0.25 (-0.43--0.08)	0.005
ε4 vs non-ε4	4	0.0001	Random	0.20 (-1.42-1.83)	0.81
ε2 vs ε3	20	< 0.00001	Random	-1.23 (-1.99--0.46)	0.002
ε3 vs ε4	20	< 0.00001	Random	-0.79 (-1.50--0.08)	0.03
ε2 vs ε4	19	< 0.00001	Random	-2.77 (-4.05--1.49)	< 0.0001