Circulating lipoprotein(a) concentrations and abdominal aortic aneurysm presence

To summarize the present evidence for an association between circulating lipoprotein(a) [Lp(a)] and abdominal aortic aneurysm (AAA) presence. MEDLINE database was searched to identify all case-control studies that compared circulating Lp(a) concentrations between patients with AAA and subjects without AAA. For each study, data regarding Lp(a) concentrations in both the AAA and control groups were used to generate standardized mean differences (SMDs) and 95% confidence intervals (CIs). Study-specific estimates were combined using inverse variance-weighted average of logarithmic SMDs in both fixed- and random-effects models. Our search identified five case-control studies. In total, our meta-analysis included data on 982 cases with AAA and 1296 controls without AAA. Pooled analysis of the five studies demonstrated significantly higher Lp(a) concentrations in the AAA group than those in the control group in random-effect models (SMD, 0.26; 95% CI, 0.08-0.44; P=0.005). There was significant study heterogeneity of results (P=0.03) but no evidence of significant publication bias (P=0.3272). We found that circulating Lp(a) concentrations are likely higher in cases with AAA than in controls without AAA. Higher circulating Lp(a) concentrations may be associated with AAA presence.