High-density lipoprotein (HDL) cholesterol - more complicated than we think?

Abstract

There are some clinical situations where a high level of HDL cholesterol (HDL-C) may be unfavourable. In these situations, HDL-C may undergo some changes, and even if its quantity is within the reference range, its quality is no longer the same. Diabetes is the state of elevated oxidative stress. Studies conducted to-date have revealed an increased production of the reactive forms of oxygen as the result of tissue damage in diabetes patients. The expression 'dysfunctional HDL' has been coined in the literature to describe high-density lipoproteins that lose their antioxidative and anti-inflammatory properties, that is, HDL-C that loses its basic functions. Recent observational studies have confirmed that the atheroprotective activity of properly functioning HDL-C is frequently impaired in clinical situations associated with oxidative stress. The presented review lays the foundation for a new approach to understanding how the functional properties of HDL help reduce cardiovascular risk. In the light of presented findings it seems that there is a need to seek a better diagnostic marker than HDL-C level. This study presents some possible directions for future research to bring us closer to the full understanding of the HDL particle and its role in patients with ischemic heart disease and type 2 diabetes.