Background: Resistin is a cysteine-rich peptide primarily secreted by inflammatory cells and adipocytes. Recent studies have linked resistin to metabolic syndrome and obesity. It is hypothesized that resistin promotes the expression of adhesion molecules on the vascular wall and induces smooth muscle cell proliferation contributing to coronary atherosclerosis. A meta-analysis was performed to evaluate the association between serum resistin levels and coronary artery disease (CAD).
Methods: We searched MEDLINE, CINAHL and COCHRANE databases for studies reporting serum-resistin levels in the patients with CAD and healthy controls. Meta-analysis included case controls, cohort and cross-sectional studies. A calculation of weighted standardized mean difference (SMD) in serum resistin level between the CAD and control groups was conducted. Residual maximum likelihood (REML) metaregression was performed on age, body mass index (BMI) and sex covariates.
Results: A literature search yielded 158 articles, but only 22 studies enrolling 8364 participants were included in the meta-analysis. The median age and BMI of the CAD group was 62 yrs.(IQR 56-64) and 27 kg/m2 (IQR 26-30) versus 57 yrs.(IQR 51-62) and 26 kg/m2 (IQR 24-30) in the control group. There were more females in the control group 41% (IQR 31-54) versus 31% (IQR 24-40) in CAD group. The unweighted median serum resistin levels in the CAD group were 9.6 ng/ml (IQR 6.1-15.6) versus 6.4 ng/ml (IQR 3.9-11.5) in the control group. The SMD of serum resistin level was 1.06 (95% CI 0.74-1.37), P<0.001 comparing those in the CAD group and control group. None of the covariates (age, BMI and sex) accounted for statistical significance.
Conclusion: An elevated serum resistin level is significantly and independently associated with presence of CAD. Further studies are needed to confirm this association by adjusting for potential confounders and evaluate the role of resistin in the risk stratifying patients with CAD.