IL-6 gene polymorphisms and CAD risk: a meta-analysis.

Area of Science:

• Genetics
• Cardiovascular Disease Epidemiology
• Molecular Biology

Background:

• Interleukin-6 (IL-6) gene polymorphisms are investigated for their role in coronary artery disease (CAD).
• Previous studies on IL-6 -174 G/C and -572 G/C variants in relation to CAD risk have yielded inconsistent findings.
• A comprehensive meta-analysis is needed to synthesize existing evidence and clarify these associations.

Purpose of the Study:

• To conduct a meta-analysis synthesizing data on IL-6 gene polymorphisms (-174 G/C and -572 G/C) and their association with coronary artery disease (CAD) risk.
• To resolve inconsistencies in previous research and provide a more definitive conclusion.
• To investigate potential ethnic differences in the observed associations.

Main Methods:

• Systematic literature search of PubMed and Embase databases up to May 22, 2012.
• Inclusion of 19 relevant studies for meta-analysis.
• Calculation of combined risk using fixed or random-effects models, with subgroup and sensitivity analyses performed.

Main Results:

• No significant overall association was found for G allele contrasts of IL-6 -174 G/C and -572 G/C polymorphisms with CAD risk.
• A significant association for the -174 G/C polymorphism (GG vs. CC) was detected (OR = 0.801, P = 0.034), but not consistently across ethnic subgroups.
• The -572 G/C polymorphism showed a significant association with CAD risk in Asian populations under a recessive model (OR = 1.908, P = 0.044).
• No significant publication bias was detected for either polymorphism.

Conclusions:

• The association between IL-6 gene -174 G/C and -572 G/C polymorphisms and CAD risk appears to be mild.
• The -572 G/C polymorphism may be associated with increased CAD risk in Asian populations.
• Further well-designed studies with larger sample sizes are required to confirm these findings and elucidate the precise relationship between IL-6 gene variants and CAD.