Association between MTHFR C677T polymorphism and abdominal aortic aneurysm risk: A comprehensive meta-analysis with 10,123 participants involved.
BACKGROUND
Abdominal aortic aneurysm (AAA) is a life-threatening condition. A number of studies reported the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and AAA risk, but substantial controversial findings were observed and the strength of the association remains unclear.


OBJECTIVE
The aim of this study was to investigate the aforementioned association in the overall population and different subgroups.


METHODS
PUBMED and EMBASE databases were searched until March 2016 to identify eligible studies, restricted to humans and articles published in English. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the susceptibility to AAA. Subgroup meta-analyses were conducted on features of the population, such as ethnicity, sex of the participants, and study design (source of control).


RESULTS
Twelve case-control studies on MTHFR C677T polymorphism and AAA risk, including 3555 cases and 6568 case-free controls were identified. The results revealed no significant association between the MTHFR C677T polymorphism and AAA risk in the overall population and within Caucasian or Asian subpopulations in all 5 genetic models. Further subgroup meta-analysis indicated that significantly increased risks were observed among cases with a mean age <70 years (OR = 1.73, 95% CI = 1.10-2.12, P = 0.02), cases with prevalence of smoking <60% (OR = 1.39, 95% CI = 1.02-1.90, P = 0.04), and cases with aneurysm diameter ≥55 mm (OR = 1.55, 95% CI = 1.07-2.24, P = 0.02) in the dominant genetic model. No publication bias was detected in the present study.


CONCLUSIONS
In conclusion, our comprehensive meta-analysis suggests that the MTHFR C677T polymorphism may play an important role in AAA susceptibility, especially in younger, non-smoking, larger AAA-diameter subgroups of patients.
Department of Vascular and Endovascular Surgery, Chinese PLA General Hospital, Beijing, China Department of Vascular and Endovascular Surgery, Shanxian Dongda Hospital, Heze, Shandong Department of Nephrology, Chinese-Japan Friendship Hospital, Beijing, China.
Jie
J
Liu
Xin
X
Jia
Haifeng
H
Li
Senhao
S
Jia
Minhong
M
Zhang
Yongle
Y
Xu
Xin
X
Du
Nianrong
N
Zhang
Weihang
W
Lu
Wei
W
Guo
D000367:Age Factors; D017544:Aortic Aneurysm, Abdominal / Q000235:genetics* / Q000473:pathology; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D044465:White People / Q000235:genetics
C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)