Severe Combined Dyslipidemia With a Complex Genetic Basis

Background. Familial dysbetalipoproteinemia (also known as type 3 hyperlipoproteinemia) is typically associated with homozygosity for the apolipoprotein E2 isoform, but also sometimes with dominant rare missense variants in the APOE gene. Patients present with roughly equimolar elevations of cholesterol and triglyceride (TG) due to pathologic accumulation of remnant lipoprotein particles. Clinical features include tuberoeruptive xanthomas, palmar xanthomas, and premature vascular disease. Case. A 48-year-old male presented with severe combined dyslipidemia: total cholesterol and TG were 11.5 and 21.4 mmol/L, respectively. He had dyslipidemia since his early 20s, with tuberous xanthomas on his elbows and knees. His body mass index was 42 kg/m². He also had treated hypertension, mild renal impairment, and a history of gout. He had no history of cardiovascular disease, peripheral arterial disease, or pancreatitis. Multiple medications had been advised including rosuvastatin, ezetimibe, fenofibrate, and alirocumab, but his lipid levels were never adequately controlled. Genetic Analysis. Targeted next-generation sequencing identified (1) the APOE E2/E2 homozygous genotype classically described with familial dysbetalipoproteinemia; (2) in addition, one APOE E2 allele contained the rare heterozygous missense variant p.G145D, previously termed apo E-Bethesda; (3) a rare heterozygous APOC2 nonsense variant p.Q92X; and (4) a high polygenic risk score for TG levels (16 out of 28 TG-raising alleles) at the 82nd percentile for age and sex. Conclusion. The multiple genetic "hits" on top of the classical APOE E2/E2 genotype likely explain the more severe dyslipidemia and refractory clinical phenotype.

[Effect of lipid-lowering activity of the natural original enzyme preparation in the experiment]

The experimental study in vivo was aimed at evaluation of hypolipidemic action of the original natural microbial enzyme preparation of cholesterol oxidase (CHO). In preliminary chronic experiments in rats, rabbits, dogs, low toxicity, good tolerability, and anti-atherosclerotic activity of the CHO preparation were established. To assess the effect of CHO under conditions of moderate, nutritional, atherogenic dyslipoproteinemia, experiments were carried out in rats, guinea pigs, and rabbits. It was shown that administration of CHO had the pronounced lipid-lowering effect in models of atherogenic dyslipoproteinemia induced in these animals.

Combination therapy of statins and fibrates in the management of cardiovascular risk

PURPOSE OF REVIEW

Despite the fact that statin treatment substantially reduces cardiovascular morbidity and mortality, many treated patients still experience a high residual risk. Statins lower LDL cholesterol (LDL-C), with limited effects on other lipid parameters. Fibrates improve atherogenic dyslipidemia characterized by high triglyceride and/or low HDL cholesterol levels and elevated concentrations of small dense LDL particles, with or without high LDL-C levels. Fibrates decrease cardiovascular morbidity, especially in patients with the metabolic syndrome. The purpose of this review is to provide a rationale for the combined use of statins and fibrates in the management of patients with high residual cardiovascular risk related to atherogenic dyslipidemia and persisting after single therapy.

RECENT FINDINGS

A meta-analysis from 14 randomized trials conducted in high-risk patients reported that statin therapy is effective in reducing the proportional risk for major vascular events by 21% for each mmol/l lowering of LDL-C. However, on an average, 14% of patients still experienced an event despite being allocated to statin. Beyond LDL-C, other factors, including triglycerides, non-HDL cholesterol, HDL cholesterol, and apolipoprotein B, have been identified as factors determining residual risk, and normalization of these parameters may further decrease cardiovascular disease in patients treated with statins. Data from fibrate trials indicate that these drugs are particularly effective in reducing cardiovascular morbidity in patients with atherogenic dyslipidemia.

SUMMARY

Reducing the residual cardiovascular risk in patients treated with statins requires addressing multiple lipid goals. In this context, future therapeutic interventions based on combination therapy, such as statins and fibrates, appear particularly promising.

Review of extended-release niacin/laropiprant fixed combination in the treatment of mixed dyslipidemia and primary hypercholesterolemia

Although statins reduce cardiovascular morbidity and mortality further risk reduction is needed. In this respect low HDL-cholesterol concentrations and/or elevated triglyceride concentrations may be potential treatment targets. Niacin (nicotinic acid) is an effective drug which increases the plasma concentration of high-density lipoprotein (HDL)-cholesterol and decreases the concentration of low-density lipoprotein (LDL)-cholesterol, triglycerides and lipoprotein(a). Clinical studies indicate that niacin can significantly reduce the risk for cardiovascular events. However, niacin is not very commonly used because of significant side effects (especially flushing). Laropiprant is a potent selective antagonist of PGD2-receptor subtype-1 and can thus reduce niacin-induced flushing. Although the addition of laropiprant will reduce the frequency of flushing, it will not completely eliminate this side effect. Laropiprant does not change the effect of niacin on lipids or other side effects of niacin (ie, gastro-intestinal problems, glucose elevation). The combination of niacin with laropiprant may therefore enable use of niacin at higher doses and therefore exploit the full potential of the drug. Endpoint studies that will be published over the next few years will show whether this treatment modality also translates into clinical effect in patients treated with statins. Until publication of these studies niacin/laropiprant should be used only in high-risk patients not achieving lipid goals on statins.

[New possibilities of genotypic in the prediction of the likelihood of autoimmune diseases]

The purpose of the study was to estimate the incidence of thyroid dysfunction and cardiovascular diseases in perimenopausal females. The cross-sectional study covered 554 females (mean age 52.6±6.1 years). The levels of thyroid-stimulating hormone (TSH), total cholesterol (TC), high-density lipoproteins (HDL), low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL), the incidence of arterial hypertension (AH), coronary heart disease, chronic heart failure, myocardial infarction, cerebral circulatory disorders, and the severity of menopausal syndrome (MS) were determined. The study detected euthyroldism in 381 (68.8%) patients, hypothyroidism in 168 (30.3%), out of them 35 (20.8%) patients having primary hypothyroidism, and hyperthyroidism in 5 (0.9%) females. Out of the 133 patients receiving L-thyroxine therapy, hypothyroidism was compensated. In 78(58.7%) cases, the dose of L-thyroxine was inadequate. The level of LDL was significantly higher in hypothyroidism; the median of TC was higher than the normal levels in both groups. There were no differences in the incidence of vascular disease between the groups. In both groups, AH was encountered In more than 60% of cases. The females with hypothyroidism had a more severe course of MS. With the adequate dose of L-thyroxine, the level of HDL was significantly higher and that of triglycerides and VLDL was lower than in hypothyroidism. It is expedient to include the measurement of TSH levels into the algorithm of examination of patients with severe MS.

[Incidence of thyroid and cardiovascular diseases in menopausal females]

The purpose of the study was to estimate the incidence of thyroid dysfunction and cardiovascular diseases in perimenopausal females. The cross-sectional study covered 554 females (mean age 52.6±6.1 years). The levels of thyroid-stimulating hormone (TSH), total cholesterol (TC), high-density lipoproteins (HDL), low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL), the incidence of arterial hypertension (AH), coronary heart disease, chronic heart failure, myocardial infarction, cerebral circulatory disorders, and the severity of menopausal syndrome (MS) were determined. The study detected euthyroldism in 381 (68.8%) patients, hypothyroidism in 168 (30.3%), out of them 35 (20.8%) patients having primary hypothyroidism, and hyperthyroidism in 5 (0.9%) females. Out of the 133 patients receiving L-thyroxine therapy, hypothyroidism was compensated. In 78(58.7%) cases, the dose of L-thyroxine was inadequate. The level of LDL was significantly higher in hypothyroidism; the median of TC was higher than the normal levels in both groups. There were no differences in the incidence of vascular disease between the groups. In both groups, AH was encountered In more than 60% of cases. The females with hypothyroidism had a more severe course of MS. With the adequate dose of L-thyroxine, the level of HDL was significantly higher and that of triglycerides and VLDL was lower than in hypothyroidism. It is expedient to include the measurement of TSH levels into the algorithm of examination of patients with severe MS.