Circulating Amyloid beta 1-40 is independently associated with statin treatment and LDL cholesterol reduction: a prospective cohort study

Abstract Background Accumulating evidence suggests that circulating amyloid beta 1-40 (Aβ40), a pro-inflammatory and pro-atherogenic peptide, is associated with atherosclerotic cardiovascular disease (ASCVD), providing incremental prognostic value and risk stratification refinement in primary and secondary prevention settings. Existing evidence supports conflicting off-target effects of statins on plasma Aβ40. We aim to explore the impact of cardiovascular risk reduction through statin therapy on Aβ40 plasma levels in subjects with dyslipidemia and with/without ASCVD. Methods In this prospective study, patients with dyslipidemia who visited for the first time our lipid clinic for risk stratification and treatment plan assessment (n=146) were consecutively recruited. Αβ40 was measured in plasma samples by enzyme-linked immunosorbent assay at baseline and after a mean follow-up of 5.2 and 15 months. Patients in whom statin treatment was initiated or intensified in terms of dose or regimen (n= 68) were compared against patients not treated with statins or with unchanged statin intensity (n = 78). Statin intensity treatment was defined based on the European Society of Cardiology (ESC) guidelines. Results Increased Aβ40 plasma levels at baseline were associated with ASCVD presence, decreased glomerular filtration rate (GFR), and history of heart failure (p<0.05 for all). An increase in Aβ40 circulating levels between baseline and follow-up 1 was observed in patients in whom statin treatment was initiated or intensified (p=0.041). However, in patients not treated with statins or treated with unchanged statin intensity, an increase in Aβ40 circulating levels was observed between follow-up 1 and follow-up 2 (p=0.05, Figure 1A). These changes in Aβ40 were significantly different between the two groups during the short follow-up period (β=0.226, p for interaction =0.025) independently from age and changes in GFR, systolic blood pressure, and LDL-C. Additionally, patients who achieved a reduction in low-density lipoprotein cholesterol (LDL-C) ≥ 50% in follow-up 2 have unchanged Aβ40 levels during the long follow-up period, while an increase in Aβ40 was observed in the rest population (p=0.012, Figure 1B). These changes were significantly different between the two LDL-C groups independently of statin treatment and changes in high sensitive C-reactive protein (hs-CRP) (β= -0.231, p for interaction=0.035). Conclusion In a dyslipidemic population, statin initiation or intensification and LDL-C decrease showed a short-term increase and a long-term return to initial levels, respectively, in circulating Aβ40 levels. From a mechanistic point of view, our findings suggest that statins have an impact on Aβ40, possibly through an LDL-C-dependent and a non-LDL-C-dependent pathway. Further studies are needed to evaluate the utility of circulating Aβ40 as a novel biomarker in ASCVD risk reduction assessment.