Addressing cardiovascular risk beyond low-density lipoprotein cholesterol: the high-density lipoprotein cholesterol story

The occurrence and potential predictive factors of major adverse cardiac and cerebral events in end-stage renal disease patients on continuous ambulatory peritoneal dialysis: A prospective cohort study

Major adverse cardiac and cerebral events (MACCE) are common complications, which prolong hospitalization and increase mortality rate in end-stage renal disease (ESRD) patients who underwent continuous ambulatory peritoneal dialysis (CAPD). Therefore, this study aimed to investigate MACCE occurrence and its potential predictive factors in those patients.In this prospective cohort study, 196 diagnosis of ESRD patients who underwent CAPD treatment in our hospital were eligible, and their clinical data (including demographic data and biochemical indexes) were documented. Besides, their MACCE occurrence was assessed within 3-year follow-up period.In patients, 1-, 2-, and 3-year MACCE occurrence rates were 5.1%, 11.7%, and 14.8%, respectively. Meanwhile, the mean duration of accumulating MACCE occurrence was 33.1 (95% confidence interval: 32.0-34.2) months. Furthermore, age, peritoneal dialysis duration (PDD), C-reactive protein (CRP), fasting blood glucose (FBG) and total cholesterol high correlated with increased accumulating MACCE occurrence, while high-density lipoprotein cholesterol (HDL-C) high correlated with decreased accumulating MACCE occurrence. Notably, by further multivariate Cox's proportional hazard regression analysis, age, PDD, CRP, serum uric acid, and FBG high were independent predictive factors for raised accumulating MACCE occurrence, while HDL-C high was an independent predictive factor for attenuated accumulating MACCE occurrence.MACCE are common; besides, age, peritoneal dialysis duration, C-reactive protein, serum uric acid, fasting blood glucose, and high-density lipoprotein cholesterol serve as potential markers for indicating MACCE in ESRD patients who underwent CAPD.

Assessment of the Antioxidant/Hypolipidemic Relationship of Sideritis hyssopifolia in an Experimental Animal Model

Many publications have described the potential cardioprotective action of different medicinal plants, relating this effect with blood lipid levels. However, these publications do not justify the right amount of plant administered, which can vary greatly. Sideritis hyssopifolia is a little woody plant endemic to western and southwestern Europe. We have quantified its antioxidant activity, which can be used as an indicator of its cardioprotective action. This study evaluates the antioxidant capacity of Sideritis hyssopifolia to design a feed whose hypolipidemic effects are proven in cholesterol-fed New Zealand rabbits. Antioxidant action was assessed in infusions, which were prepared with 1 or 3 g of plant in 200 mL of water by using an ABTS assay and expressed as Ascorbic acid Equivalent Antioxidant Capacity (AEAC). Aqueous infusions with infusion times of 10 min and prepared with 3 g plant exhibited the strongest antioxidant activity. Sideritis hyssopifolia showed an intermediate antioxidant capacity for the concentrations and times of the infusion tested. According to our results, we suggest incorporating 2.36 g of S. hyssopifolia every 150 g of rabbit feeding stuff (15.73 g/kg). This chow decreased cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides levels in cholesterol-fed rabbits, as well as the atherogenic index. This reduction was similar to that obtained with simvastatin.

Posttraumatic stress disorder and dyslipidemia: previous research and novel findings from patients with PTSD caused by myocardial infarction

OBJECTIVES

Based on a brief systematic review suggesting dyslipidemia in posttraumatic stress disorder (PTSD), we studied, for the first time, levels of blood lipids in patients with a DSM-IV diagnosis of PTSD caused by myocardial infarction (MI).

METHODS

Study participants were eight patients with full PTSD, eight patients with subsyndromal PTSD, and 31 patients with no PTSD who were diagnosed using the Clinician-Administered PTSD Scale (CAPS) interview after a mean of 32+/-8 months after MI. Levels of total cholesterol, low-density lipoprotein-cholesterol, triglycerides, and high-density lipoprotein-cholesterol (HDL-C) were determined in plasma.

RESULTS

Patients with full PTSD had lower HDL-C than patients with subsyndromal PTSD (P = 0.044) and those with no PTSD (P = 0.014) controlling for sex, body mass index, and statin equivalent dosage. Moreover, HDL-C levels were inversely associated with PTSD total symptoms (r = -0.33, P = 0.027), re-experiencing symptoms (r = -0.32, P = 0.036), and avoidance symptoms (r = -0.34, P = 0.025). There were no significant associations of PTSD diagnostic status and symptomatology with the three other lipid measures.

CONCLUSION

Chronic PTSD caused by MI was associated with lower plasma levels of HDL-C. The finding concurs with the notion of dyslipidemia partially underlying the atherosclerotic risk in individuals with PTSD caused by different types of trauma.

Structure and stability of apolipoprotein a-I in solution and in discoidal high-density lipoprotein probed by double charge ablation and deletion mutation

To identify residues and segments in the central region of apolipoprotein A-I (apoA-I) that are important for the protein structure and stability, we studied the effects of four double charge ablations, D102A/D103A, E110A/E111A, R116V/K118A, and R160V/H162A, and two deletion mutations, Delta(61-78) and Delta(121-142), on the conformation and stability of apoA-I in the lipid-free state and in reconstituted discoidal phospholipid-cholesterol-apoA-I particles (rHDL). The findings suggest that D102/D103 and E110/E111 located in helix 4 and segment(s) between residues 61 and 78 are involved in maintenance of the conformation and stability of apoA-I in both the lipid-free state and in rHDL. R116/K118 located in helix 4 are essential for the conformation and stabilization of apoA-I in rHDL but not vital for the lipid-free state of the protein. The R160V/H162A substitutions in helix 6 lead to a less compact tertiary structure of lipid-free apoA-I without notable effects on the lipid-free or lipid-bound secondary conformation, suggesting involvement of R160/H162 in important interhelical interactions. The results on the Delta(121-142) mutant, together with our earlier findings, suggest disordered structure of a major segment between residues 121 and 143, likely including residues 131-143, in lipid-free apoA-I. Our findings provide the first experimental evidence for stabilization of rHDL by specific electrostatic interhelical interactions, in agreement with the double belt model. The effects of alterations in the conformation and stability of the apoA-I mutants on in vitro and in vivo functions of apoA-I and lipid homeostasis are discussed.

Apolipoprotein structural organization in high density lipoproteins: belts, bundles, hinges and hairpins

PURPOSE OF REVIEW

To summarize recent advances towards an understanding of the three-dimensional structures of the apolipoprotein components of HDL with a specific focus on high resolution models of apolipoprotein A-I.

RECENT FINDINGS

Since the primary sequence was first reported, various models have been advanced for the structure of apolipoprotein A-I, the major protein constituent of HDL, in its lipid-free and lipid-bound forms. Unfortunately, the generation of experimental data capable of distinguishing among the competing models has lagged far behind. However, recent experimental strategies, including X-ray crystallography, applications of resonance energy transfer and mass spectrometry, have combined with sophisticated theoretical approaches to develop three-dimensional structural models of apolipoprotein A-I with previously unavailable resolution.

SUMMARY

The recent synergy of sophisticated computer modeling techniques with hard experimental data has generated new models for apolipoprotein A-I in certain subclasses of HDL produced in vitro. The challenge now is to adapt and test these models in the more complex forms of HDL isolated directly from human plasma.