HDL functions and their interaction in patients with ST Elevation Myocardial Infarction: a case control study

Abstract

Background : Recent studies emphasize the importance of HDL function over HDL cholesterol measurement, as an important risk for cardiovascular diseases (CVD). We compared the HDL function of patients with Acute Coronary Syndrome (ACS) and healthy controls. Methods : We measured cholesterol efflux capacity of HDL using THP-1 macrophages labelled with fluorescently tagged (BODIPY) cholesterol. Paraoxonase and arylesterase activity of PON1 enzyme were assessed by spectrophotometric methods. Results : We recruited 151 ACS patients and 110 controls. The HDL function of all patients during acute phase and at six month follow-up was measured. The mean age of the patients and controls was 51.7 and 43.6 years respectively. The mean HDL cholesterol/apolipoprotein A-I levels (ratio) of patients during acute phase, follow-up and of controls were 40.2 mg/dl/ 112.5 mg/dl (ratio= 0.36), 38.3 mg/dl/ 127.2 mg/dl (ratio= 0.30) and 45.4 mg/dl/ 142.1 mg/dl (ratio=0.32) respectively. The cholesterol efflux capacity (CEC) of HDL was positively correlated with apolipoprotein A-I levels during acute phase (r = 0.19, p = 0.019), follow-up (r = 0.26, p = 0.007) and of controls (r = 0.3, p = 0.0012) but not with HDL-C levels (acute phase: r = 0.07, p = 0.47; follow-up: r = 0.1 , p = 0.2; control: r = 0.02, p = 0.82). Higher levels of cholesterol efflux capacity, PON1 activity and apolipoprotein A-I were associated with lower odds of development of ACS. We also observed that low CEC is associated with higher odds of having ACS if PON1 activity of HDL is also low and vice versa. Conclusion : ACS is associated with reduced HDL functions which improves at follow-up. The predicted probability of ACS depends upon individual HDL functions and the interactions between them.

Long-Term Effects of Critical Care Insults on Lipoprotein Metabolism

“…In non-survivors, cholesterol levels continued to decline until death. Again, this is consistent with prior observations [30,44,55].…”

“…Acute changes in lipoproteins do not follow a "typical" pattern of change considering the fact that serum HDL-lipoprotein levels were not depressed during acute illness [55][56][57]. LDL-c was lower during acute ACS, but it is unclear how long these changes persisted [55][56][57]. This lipid profile predicted mortality acutely, but these findings are inconsistent with other studies demonstrating depression of LDL-c and HDL-c during acute phase of CCI [58].…”

“…Despite numerous studies demonstrating the pivotal role of lipoprotein profile abnormalities in the development of atherosclerosis and the increased risk of acute coronary syndrome (ACS), little is known regarding how ACS as CCI affects the progress of atherosclerosis [9,10]. Acute changes in lipoproteins do not follow a "typical" pattern of change considering the fact that serum HDL-lipoprotein levels were not depressed during acute illness [55][56][57]. LDL-c was lower during acute ACS, but it is unclear how long these changes persisted [55][56][57].…”

Additive Effects of Drinking Habits and a Susceptible Genetic Polymorphism on Cholesterol Efflux Capacity

“…Several limitations of the present study should be noted. APOA-I is a small sized particle in HDL and has been reported to be more closely related to CEC levels than HDL-C levels 49,50) . Therefore, it is important to examine the relationship between drinking habits, APOA-1 and CEC levels in order to clarify the effects of drinking habits on CEC levels, but we were unable to measure APOA1 levels in our study.…”