Impaired fibrinolytic activity is present in children with dyslipidemias

Hyperlipidemia and Cardiovascular Risk in Children and Adolescents

Atherosclerotic cardiovascular disease (ASCVD) represents the major cause of morbidity and mortality worldwide. The onset of the atherosclerosis process occurs during childhood and adolescence, subsequently leading to the onset of cardiovascular disease as young adults. Several cardiovascular risk factors can be identified in children and adolescents; however, hyperlipidemia, in conjunction with the global obesity epidemic, has emerged as the most prevalent, playing a key role in the development of ASCVD. Therefore, screening for hyperlipidemia is strongly recommended to detect high-risk children presenting with these disorders, as these patients deserve more intensive investigation and intervention. Treatment should be initiated as early as possible in order to reduce the risk of future ASCVD. In this review, we will discuss lipid metabolism and hyperlipidemia, focusing on correlations with cardiovascular risk and screening and therapeutic management to reduce or almost completely avoid the development of ASCVD.

Statins and Hemostasis: Therapeutic Potential Based on Clinical Evidence

Hemostasis preserves blood fluidity and prevents its loss after vessel injury. The maintenance of blood fluidity requires a delicate balance between pro-coagulant and fibrinolytic status. Endothelial cells (ECs) in the inner face of blood vessels maintain hemostasis through balancing anti-thrombotic and pro-fibrinolytic activities. Dyslipidemias are linked to hemostatic alterations. Thus, it is necessary a better understanding of the underlying mechanisms linking hemostasis with dyslipidemia. Statins are drugs that decrease cholesterol levels in the blood and are the gold standard for treating hyperlipidemias. Statins can be classified into natural and synthetic molecules, approved for the treatment of hypercholesterolemia. The classical mechanism of action of statins is by competitive inhibition of a key enzyme in the synthesis pathway of cholesterol, the HMG-CoA reductase. Statins are frequently administrated by oral ingestion and its interaction with other drugs and food supplements is associated with altered bioavailability. In this review we deeply discuss the actions of statins beyond the control of dyslipidemias, focusing on the actions in thrombotic modulation, vascular and cardiovascular-related diseases, metabolic diseases including metabolic syndrome, diabetes, hyperlipidemia, and hypertension, and chronic diseases such as cancer, chronic obstructive pulmonary disease, and chronic kidney disease. Furthermore, we were prompted to delved deeper in the molecular mechanisms by means statins regulate coagulation acting on liver, platelets, and endothelium. Clinical evidence show that statins are effective regulators of dyslipidemia with a high impact in hemostasis regulation and its deleterious consequences. However, studies are required to elucidate its underlying molecular mechanism and improving their therapeutical actions.

DNA methylations of MC4R and HNF4α are associated with increased triglyceride levels in cord blood of preterm infants

The association of preterm birth with obesity and metabolic syndrome later in life is well established. Although the biological mechanism for this association is poorly understood, epigenetic alterations of metabolic-related genes in early life may have important roles in metabolic dysfunction. Thus, we investigated the associations of DNA methylations of melanocortin 4 receptor (MC4R) and hepatocyte nuclear factor 4 alpha (HNF4α) with metabolic profiles in cord blood of term and preterm infants.We measured metabolic profiles in cord blood samples of 85 term and 85 preterm infants. DNA methylation and mRNA expression levels of MC4R and HNF4α in cord blood cells were quantified using pyrosequencing and real-time PCR. Triglyceride (TG) levels were grouped by percentile as low (<10th percentile), mid (11th-89th percentiles), and high (>90th percentile). A multiple linear regression model was used to assess the differential effects of DNA methylation on metabolic indices in cord blood between term and preterm infants.The beta-coefficients for associations between TG levels and methylation statuses of MC4R-CpG3 and HNF4α-CpG2 in the P1 promoter differed significantly between term and preterm infants (P = 0.04 and P = 0.003, respectively). DNA methylation statuses of MC4R-CpG3 and HNF4α-CpG2 in the P1 promoter were significantly lower in preterm infants in the high-TG group compared with those in the mid- and low-TG groups (P = 0.01). Notably, preterm infants in the high-TG group had higher TG levels in cord blood than term infants in the high-TG group (60.49 vs 54.57 mg/dL). In addition, MC4R and HNF4α expression levels were higher in preterm infants than in term infants (P < 0.05).Epigenetic alterations of the newly identified genes MC4R and HNF4α in early life might contribute to metabolic profile changes, especially increased TG levels, in the cord blood of preterm infants.

Childhood obesity: evidence of an association between plasminogen activator inhibitor-1 levels and visceral adiposity

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-1) has been considered as a cardiovascular risk factor, mainly because of its strong association with insulin resistance.

METHODS

To detect independent predictors of circulating PAI-1 levels in obese pediatric patients, we evaluated 86 subjects (mean age 10.7 +/- 2.8 years), 42 of whom were male (49%). Subjects were divided in two groups according to body mass index (BMI): obese subjects (n=61) and healthy non-obese controls (n=25). They were also divided by pubertal status. Besides anthropometric data, levels of PAI-1, leptin and biochemical markers of metabolic syndrome were measured.

RESULTS

The obese group had higher levels of PAI-1, leptin and biochemical markers of metabolic syndrome than nonobese controls (p<0.05). However, multivariate regression analysis showed that only puberty progression (p=0.005) and abdominal circumference/height index (p=0.002) remained independent predictors of PAI-1 levels.

CONCLUSION

In pediatric obesity, fat mass accumulation, mainly of visceral fat, and puberty progression were related to high PAI-1 levels, which might in turn contribute to cardiovascular risk.

[Values of high-density lipoprotein cholesterol in the pediatric population and risk of thrombosis]

INTRODUCTION

There is evidence of the protective effect of high-density lipoprotein (HDL)-cholesterol against atheroma plaque formation and of its role in cholesterol efflux from cells, as well as its anti-oxidative and inflammatory modulating response properties. Low HDL-cholesterol levels have been associated with a prothrombotic state.

OBJECTIVE

To determine the relationship between HDL-cholesterol and lipidic and hemostatic parameters.

PATIENTS AND METHODS

We studied 110 children (50 girls, 60 boys) aged between 6 and 7 years old. Lipid profile, D-dimer, plasminogen activator inhibitor (PAI) and fibrinogen were determined.

RESULTS

The mean values of the studied parameters were as follows: total cholesterol (192.92+/-26.01 mg/dl), HDL-cholesterol (72.87+/-15.69 mg/dl), low-density lipoprotein-cholesterol (109.46+/-23.30 mg/dl), triglycerides (56.24+/-20.35 mg/dl), apolipoprotein B (91.96+/-14.93 mg/dl), apolipoprotein A1 (168.4+/-24.55 mg/dl), lipoprotein(a) logarithm (1.76+/-1.36 mg/dl), plasminogen activator inhibitor-1 logarithm (PAI-1) (3.77+/-3.93 U/ml), D-dimer logarithm (5.53+/-0.49 ng/ml) and fibrinogen (268.61+/-48.59 mg/dl). When the sample was divided into two groups according to HDL-cholesterol levels, children with lower levels showed significantly higher values of total cholesterol/HDL-cholesterol, fibrinogen and PAI. HDL-cholesterol levels were directly and significantly associated with total cholesterol and apolipoprotein A1 and negatively and significantly associated with the total cholesterol/HDL-cholesterol ratio, fibrinogen and PAI.

CONCLUSION

The children studied had high HDL-cholesterol levels, which could be responsible for the high total cholesterol levels. High values of HDL-cholesterol are significantly associated with a reduction in thrombotic risk.

Cardiovascular risk reduction in high-risk pediatric patients: a scientific statement from the American Heart Association Expert Panel on Population and Prevention Science; the Councils on Cardiovascular Disease in the Young, Epidemiology and Prevention, Nutrition, Physical Activity and Metabolism, High Blood Pressure Research, Cardiovascular Nursing, and the Kidney in Heart Disease; and the Interdisciplinary Working Group on Quality of Care and Outcomes Research

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

Cardiovascular Risk Reduction in High-Risk Pediatric Patients

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

The effect of plasminogen activator inhibitor-1 gene 4G/5G polymorphism on glucose and lipid metabolisms in Turkish obese children

OBJECTIVE

Obesity is a metabolic disorder that is associated with increased plasminogen activator inhibitor-1 (PAI-1) concentration in the circulation. This increase is related to insulin resistance, dyslipidaemia and cardiovascular disease. Some studies have demonstrated a relationship between plasma PAI-1 concentrations and the 4G/5G gene polymorphism in the PAI-1 gene, while other studies have not. It is well known that plasma PAI-1 levels are increased in obesity; however, the relationship between the polymorphism and obesity remains unclear. In this study, we aimed to elucidate the effect of the PAI-1 4G/5G polymorphism on glucose and lipid metabolism parameters in Turkish obese children.

DESIGN AND PATIENTS

Ninety children with obesity (37 male, 53 female; mean age 11.1 +/- 3.4 years; range 5.8-17.6 years) were included in the study. The children were divided into three groups according to the PAI-1 promoter 4G/5G polymorphism (4G/4G, 4G/5G and 5G/5G). These groups were compared for age, body mass index (BMI), serum glucose, lipid and insulin levels, and homeostasis model assessment of insulin resistance (HOMA-IR) score.

RESULTS

The genotype distribution was 52% (47/90) 4G/4G, 25% (22/90) 4G/5G and 23% (21/90) 5G/5G. No statistically significant differences among genotype groups were found with respect to age, BMI, serum levels of glucose, lipid and insulin, and HOMA-IR score.

CONCLUSION

Although the frequency of the 4G/4G genotype was higher in subjects in the current study than in subjects reported in the literature, in our study group we observed no influence of the PAI-1 4G/4G polymorphism on lipid and glucose metabolism.

Hyperlipidemia in children

Hyperlipidemia in children has emerged as an increasingly prevalent risk factor in children, concomitant with the worldwide epidemic of obesity. Hyperlipidemia can alter vascular endothelial function and impair some of its pro-fibrinolytic and anti-thrombotic regulatory properties, as well as initiate the atherosclerotic process. There are strong links between vascular changes and hyperlipidemia in children, both from pathologic and non-invasive assessment studies. More severe lipid abnormalities in children are related to primary familial dyslipidemias. Current recommendations for screening begin with assessment of family history for cardiovascular disease or events or parental hyperlipidemia. High-risk individuals merit more intensive investigation and intervention. While fat-restricted diets have been shown to be safe in children, lipid-lowering is modest. Those with more severe lipid abnormalities may meet criteria for drug therapy, and the statin agents commonly used in adults are increasingly being used in high-risk children, with similar efficacy and safety, although long-term concerns remain.