Relationships of Statin Therapy and Hyperlipidemia With the Incidence, Rupture, Postrepair Mortality, and All-Cause Mortality of Abdominal Aortic Aneurysm and Cerebral Aneurysm: A Meta-analysis and Systematic Review

Abstract

Statins have been suggested in previous studies to play a protective role in experimental cerebral aneurysm (CA) models; however, no evidence supports that the application of statins can protect against aneurysm rupture in humans, and the risks of lipid levels and aneurysms remain unknown. Therefore, this meta-analysis aimed to summarize and update the epidemiological evidence to systematically assess the relationships of statin therapy and hyperlipidemia with the incidence, rupture, postrepair mortality, and all-cause mortality of abdominal aortic aneurysm (AAA) and CA. Related studies were initially retrieved from the electronic databases PubMed, Embase, and Cochrane Library from inception to August 4, 2018. Subsequently, 33 studies were enrolled into this meta-analysis, and the maximum adjusted risk ratios (RRs) as well as the corresponding 95% confidence intervals were extracted. Finally, a total of 32 observational studies involving 150,134 participants were enrolled into this meta-analysis. The RRs of statin therapy for AAA incidence, AAA rupture, CA rupture, postrepair mortality, all-cause mortality, and adverse events were 1.83 (0.56–5.98), 0.67 (0.47–0.97), 0.50 (0.18–1.36), 0.60 (0.48–0.74), 0.66 (0.58–0.75), and 0.58 (0.47–0.71), respectively. Besides, the RR of hyperlipidemia for CA rupture was 0.79 (0.67–0.93). Our findings suggested that statin therapy could reduce the risks of AAA rupture, postrepair mortality, all-cause mortality, and adverse events, without inducing the risk of AAA incidence or CA rupture, and that hyperlipidemia was associated with a lower risk of CA rupture.

Effects of hypercholesterolism on expansion of abdominal aortic aneurysm in rat model

“…Evidence both in vitro and in vivo found that statin therapy downregulates the expression of metalloproteinase [23,25]. The current study found that between hypercholesterol groups (group III and IV), AD3 was signi cantly larger in group III (statin(-)) compared with group IV (statin(+)) and AD3/AD1 was higher in group III compared to group II although this difference did not reach statistical signi cance.…”

“…Salata et al [22], suggested that statin application would not only reduce the growth rate of AAA but could also reduce the risk of mortality in patients undergoing open repair perioperatively. Although the underlying mechanism has not been well understood thus far, statin application has exerted protective effects on the endothelial function, in ammatory reaction, oxidative stress, thrombosis and plaque stability, affecting the occurrence of cardiovascular complications and the progression of AAA [23,24]. Luan et al [25], demonstrated that statin application would alter the in ammatory environment of aneurysm in ammation, rather than directly lowering the blood lipid levels.…”

Effects of hypercholesterolism on expansion of abdominal aortic aneurysm in rat model

“…Salata et al [ 6 ], suggested that statin application would not only reduce the growth rate of AAA but could also reduce the risk of mortality in patients undergoing open repair perioperatively. Although the underlying mechanism has not been well understood thus far, statin application has exerted protective effects on the endothelial function, inflammatory reaction, oxidative stress, thrombosis and plaque stability, affecting the occurrence of cardiovascular complications and the progression of AAA [ 21 , 22 ]. Luan et al [ 23 ], demonstrated that statin application would alter the inflammatory environment of aneurysm inflammation, rather than directly lowering the blood lipid levels.…”

APOA1 oxidation is associated to dysfunctional high-density lipoproteins in human abdominal aortic aneurysm

“…However, recent genetic studies suggest that lipids could play a role in the etiology of AAA [[7], [8], [9], [10]]. Similarly, the effect of statins on AAA displayed contradictory results, although more recent studies support a protective role of these drugs in preventing AAA growth and rupture [[11], [12], [13]]. Regardless of the potential contribution of lipids on AAA progression, it is well accepted that low levels of high-density lipoprotein (HDL) cholesterol are associated to both AAA presence and evolution [14,15].…”