Author Interviews, Heart Disease, Lipids / 20.11.2015
HDL Levels in Acute Coronary Syndrome May Reflect Inflammatory Response
MedicalResearch.com Interview with:
Dr. Héctor González-Pacheco MD
Coronary Care Unit, National Institute of Cardiology
Mexico City, Mexico
Medical Research: What is the background for this study?
Dr. González-Pacheco: Epidemiological studies have provided robust evidence for an inverse correlation between plasma levels of high-density lipoprotein cholesterol (HDL-C) and cardiovascular risk. At hospital admission, a high percentage of patients with an acute coronary syndrome (ACS) have low HDL-C levels. Currently, the association of very low levels of HDL-C with early mortality in patients with ACS is still a topic of considerable interest. However, the possible mechanisms are not clear. Since an acute coronary syndrome induces an inflammatory response, and several chronic systemic diseases and acute critical illnesses with clear pro-inflammatory components have been associated with significantly reduced HDL-C levels, and investigators have shown an inverse correlation between HDL-C levels and the levels of pro-inflammatory cytokines, we hypothesized that reduced HDL-C levels in acute coronary syndrome might be associated to inflammatory mediators. We therefore sought to evaluate the correlation between HDL-C levels and biomarkers of inflammation available in routine laboratory screenings (high-sensitivity C-reactive protein (hs-CRP), white blood cell (WBC) count, and serum albumin) in a retrospective cross-sectional study of patients with ST-elevation myocardial infarction (STEMI) or non-ST-elevation ACS (NSTE-ACS).
Medical Research: What are the main findings?
Dr. González-Pacheco: We found that approximately one-fifth of patients had very low HDL-C levels (<30 mg/dL). Baseline levels of hs-CRP were significantly higher in these patients than in those with low (30–39.9 mg/dL) and normal (≥40 mg/dL) HDL-C levels. In contrast, serum albumin values were lower in patients with very low HDL-C levels. WBC count did not differ significantly. Accordingly, hs-CRP levels ≥ 10 mg/L and serum albumin levels ≤ 3.5 mg/dL, were two strong independent predictors of very low HDL-C levels. We observed that patients with STEMI had higher expression of biomarkers of inflammation and lower levels of HDL-C, compared with NSTE-ACS patients, as well as a lack of significant difference in the extent of coronary disease among the categories of HDL-C levels. These findings suggest that the fall in HDL-C levels is in accordance with the severity of the inflammatory response and the extent of the myocardial damage. Our findings are consistent with previous studies, in which patients with very low HDL levels had a higher rate of in-hospital mortality compared with those of other HDL-C levels.
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