Low levels of high-density lipoprotein cholesterol (HDL-C) have been associated with increased cardiovascular
(CV) risk. These beneficial effects of HDL can be, at least partly, attributed to its anti-inflammatory, antithrombotic, antioxidant
and endothelial-protective properties. However, the results of some clinical trials aiming at raising HDL-C levels
are conflicting in terms of CV protection suggesting that alterations in HDL quality (and not only quantity) are involved in
the atherosclerotic process. In this context, inflammation, oxidation, infection, hyperglycemia and activated platelets may
modify HDL components, thus transforming HDL to a dysfunctional molecule with pro-atherogenic properties. Furthermore,
some recent trials with HDL-raising drugs, such as niacin and torcetrapib, reported a lack of benefit in terms of vascular
risk as well as adverse events including cancer and infections. In this narrative review, the findings of recent HDL
clinical studies in relation to CV events as well as the associations of HDL with cancer and infections are discussed. The
possible pathogenic mechanisms of these associations are also considered. The clinical implications of HDL function in
treating patients at high CV risk remains to be established in future trials.
Cancer, cardiovascular disease, high-density lipoprotein cholesterol, high-density lipoprotein dysfunction, infection,
Dept. of Clinical Biochemistry (Vascular Disease Prevention Clinics), Royal Free Hospital campus, University College London Medical School, University College London (UCL), Pond Street London NW3 2QG, UK.