Risk factors: Lipoprotein(a) and coronary disease-moving closer to causality

Higher Lipoprotein (a) Levels Are Associated with Better Pulmonary Function in Community-Dwelling Older People - Data from the Berlin Aging Study II

Reduced pulmonary function and elevated serum cholesterol levels are recognized risk factors for cardiovascular disease. Currently, there is some controversy concerning relationships between cholesterol, LDL-cholesterol, HDL-cholesterol, serum triglycerides and lung function. However, most previous studies compared patients suffering from chronic obstructive pulmonary disease (COPD) with healthy controls, and only a small number examined this relationship in population-based cohorts. Moreover, lipoprotein a [Lp(a)], another lipid parameter independently associated with cardiovascular diseases, appears not to have been addressed at all in studies of lung function at the population level. Here, we determined relationships between lung function and several lipid parameters including Lp(a) in 606 older community-dwelling participants (55.1% women, 68±4 years old) from the Berlin Aging Study II (BASE-II). We found a significantly lower forced expiration volume in 1 second (FEV1) in men with low Lp(a) concentrations (t-test). This finding was further substantiated by linear regression models adjusting for known covariates, showing that these associations are statistically significant in both men and women. According to the highest adjusted model, men and women with Lp(a) levels below the 20^th percentile had 217.3ml and 124.2ml less FEV1 and 239.0ml and 135.2ml less FVC, respectively, compared to participants with higher Lp(a) levels. The adjusted models also suggest that the known strong correlation between pro-inflammatory parameters and lung function has only a marginal impact on the Lp(a)-pulmonary function association. Our results do not support the hypothesis that higher Lp(a) levels are responsible for the increased CVD risk in people with reduced lung function, at least not in the group of community-dwelling older people studied here.

Lipoprotein(a): a promising marker for residual cardiovascular risk assessment

Atherosclerotic cardiovascular diseases (CVD) are still the leading cause of morbidity and mortality worldwide, although optimal medical therapy has been prescribed for primary and secondary preventions. Residual cardiovascular risk for some population groups is still considerably high although target low density lipoprotein-cholesterol (LDL-C) level has been achieved. During the past few decades, compelling pieces of evidence from clinical trials and meta-analyses consistently illustrate that lipoprotein(a) (Lp(a)) is a significant risk factor for atherosclerosis and CVD due to its proatherogenic and prothrombotic features. However, the lack of effective medication for Lp(a) reduction significantly hampers randomized, prospective, and controlled trials conducting. Based on previous findings, for patients with LDL-C in normal range, Lp(a) may be a useful marker for identifying and evaluating the residual cardiovascular risk, and aggressively lowering LDL-C level than current guidelines' recommendation may be reasonable for patients with particularly high Lp(a) level.

Emerging genomic applications in coronary artery disease

Over the last 4 years, an unprecedented number of studies illuminating the genomic underpinnings of common "polygenic" diseases including coronary artery disease have been published. Notably, these studies have established numerous deoxyribonucleic acid (DNA) variants within or near chromosome 9p21.3, the LPA, CXADR, and APOE genes, to name a few, as key coronary artery disease and sudden cardiac death susceptibility markers. Most importantly, many of these DNA variants confer over a 2-fold increase in risk for coronary artery disease, myocardial infarction, and ventricular fibrillation. Additionally, loss-of-function variants in the hepatic cytochrome 2C19 system have now been found to be the predominant genetic mediators of clopidogrel antiplatelet response, with variant carriers having a >3-fold increase in risk for stent thrombosis. In the near future, many additional rare polymorphisms, structural variants, and tissue-specific epigenetic features of the human genome including DNA methylation, histone modifications, and chromatin state will emerge as significant contributors to disease pathogenesis and drug response. In aggregate, these findings will have the potential to radically change the practice of cardiovascular medicine. However, only the individual clinician can ultimately enable the translation of these important discoveries to systematic implementation in clinical practice.