Increased Risk of Clopidogrel-Induced Gastric Mucosal Erosion in Elderly Chinese Men Harboring the ABCB1 3435T Allele

Figures & data

Table 1 Demographic and Clinical Characteristics of the Study Patients

Variable	Control n = 201	Case n = 97	P
Age, yrs	76.9 (8.7)	80.3 (9.2)	0.77
Body mass index (kg/m^2)	25.2 (2.1)	24.3 (2.5)	0.83
SBP (mmHg)	138.8 (12.4)	141.9 (13.2)	0.57
DBP (mmHg)	70.1 (10.5)	63.7 (8.8)	0.33
Platelet count (10^9 cells/l)	213.4(50.2)	199.4(54.1)	0.47
Platelet inhibition rate (%)	42.8(21.4)	54.0(23.7)	0.02
Serum creatinine (umol/l)	82.3 (39.8)	88 (32.3)	0.18
eGFR (mL/min/1.73m^2)	73.2 (17.7)	61.8 (18.2)	0.11
Alcohol drinking n, (%)	23 (11.4)	5 (5.2)	0.08
Smoking n, (%)	47 (23.4)	19 (19.6)	0.46
H. pylori-positive, n (%)	29 (14.4)	21 (16.2)	0.11
History of gastric ulcer, n (%)	38 (18.9)	33 (34.0)	0.004
Diabetes mellitus, n (%)	52 (25.9)	37 (38.1)	0.03
Hypertension, n (%)	86 (40.8)	42 (43.3)	0.67
Hyperlipidemia, n (%)	39 (19.4)	8 (8.2)	0.013
Ischemic heart disease, n (%)	59 (29.4)	41 (42.3)	0.027
Cerebrovascular disease, n (%)	23 (11.4)	15 (15.5)	0.33
PPI, n %)	41(20.4)	29(29.9)	0.07
Statins, n (%)	126(62.7)	43(44.3)	0.003

Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; PPI, proton pomp inhibitor: rabeprazole 10 mg/day; Statins, atorvastatin 10 mg/day or rosuvastatin 5 mg/day.

Table 2 Allele and Genotype Frequencies of CYP2C19 and ABCB1 in Patients Taking Clopidogrel

Variable	Allele Frequencies p† Value for HWE	Genotype	Control n=201 (%)	Case n=97 (%)	P
CYP2C19*2 681 G >A rs 4244285	G=0.79 A=0.21 P†=0.07	GG GA AA	128(63.7) 59(29.4) 14(7.0)	64(66.0) 29(29.9) 4 (4.1)	0.627
A allele carrier			73 (36.3)	33(34.0)	0.698
CYP2C19*3 636 G >A rs 4986893	G=0.96 A=0.04 P†=0.43	GG GA AA	184(91.5) 17(8.5) 0	88(90.7) 9(9.3) 0	0.814
A allele carrier			17(8.5)	9(9.3)	0.814
CYP2C19*17 806 C >T rs 12248560	C=0.99 T=0.01 P†=0.84	CC CT TT	198(98.5) 3(1.5) 0	93(95.9) 4(4.1) 0	0.22
T allele carrier			3(1.5)	4 (4.1)	0.22
ABCB1 3435C >T rs 1045642	C=0.66 T=0.34 P†=0.07	CC CT TT	104(51.7) 72(35.8) 25(12.4)	34(35.1) 47(48.5) 16(16.5)	0.026
T allele carrier			97(48.3)	63(64.9)	0.007

Notes: P values by chi-squared test: ^†Hardy–Weinberg equilibrium (HWE) of allele frequencies at individual loci was assessed by comparing the observed and expected genotype frequencies.

Table 3 Association Between Various Related Factors and Gastric Mucosal Erosion in Patients Taking Clopidogrel

	Mantel-Haenszel OR (95% CI)	Adjusted OR (95% CI)
Platelet inhibition rate	——	1.30 (0.62–1.94)
History of gastric ulcer	2.21 (1.28–3.83)**	3.11 (1.84–5.05)**
Diabetes mellitus	1.77 (1.05–2.96)*	2.37 (1.49–4.60)*
Hyperlipidemia	0.37 (0.17–0.83)*	0.69 (0.33–1.19)
Ischemic heart disease	1.76 (1.06–2.92)*	1.44 (0.81–2.25)
Statins	0.47 (0.29–0.78)**	0.58 (0.36–0.93)*
ABCB1 3435 T allele carrier	1.99 (1.20–3.28)**	2.14 (1.43–3.84)**

Notes: The unadjusted OR and 95% CI were obtained by Mantel–Haenszel statistics and the adjusted OR and 95% CI were obtained by multiple logistic regression analysis after adjustment for the other factors. *p < 0.05. **p < 0.01.