Intraindividual variability of children's blood lipid and lipoprotein concentrations: a review

Total cholesterol and low-density lipoprotein alterations in children and adolescents from Brazil: a prevalence meta-analysis

Objective

The aim of the present study was to evaluate the prevalence of total cholesterol (TC) and low-density lipoprotein (LDL) alterations in children and adolescents in Brazil.

Subjects and methods

A systematic review and meta-analysis of prevalence. The search for articles was carried out in the databases: Medline (PubMed), Embase, Scientific Electronic Library Online (SciELO), Latin American and Caribbean Literature in Health Sciences (Lilacs). The meta-analysis was performed using the random effects model. The I² test was used to identify heterogeneity.

Results

The present metanalysis revealed a significant prevalence of altered lipid profile in children and adolescents in Brazil. Regarding lipoprotein fractions, the prevalence of altered TC level was 27.47% (95% CI 24.36-30.82), and a smaller prevalence was observed for LDL cholesterol (19.29% - 95% CI 15.21-24.16). The models revealed high heterogeneity (I² = 99%; p < 0.01), however the precise source of it was not identified; although type of school, age group, year and the region of Brazil appeared to influence the estimations of altered lipid profiles.

Conclusion

An important prevalence of lipid alterations was observed among Brazilian children and adolescents. Those results reinforce the importance of knowing the lipid profile of children and adolescents to perform early interventions for this public.

Association of cytochromes P450 3A4*22 and 3A5*3 genotypes and polymorphism with response to simvastatin in hypercholesterolemia patients

Backgrounds

Inter-individual variability in response to statin was mainly due to genetic differences. This study aimed to investigate the association of CYP3A4*22 (rs35599367), CYP3A5*3 (rs776746) single nucleotide polymorphism (SNP) with response to simvastatin in hypercholesterolemia patients conducted at King Abdulaziz University hospital (KAUH) in Jeddah, Saudi Arabia.

Patients and methods

A total of 274 participants were registered in the current study. Hypercholesterolemic patients taking simvastatin 20 mg (n = 148) and control subjects (n = 126) were tested for rs35599367 and rs776746 genotypes using Custom Taqman ® Assay Probes. Response to simvastatin in these patients was assessed by determination of low density lipoprotein (LDL-C), total cholesterol (TC) and by measuring statin plasma levels using Liquid Chromatography-Mass Spectrometry (LC-MS).

Results

None of the participants carried a homozygous CYP3A4*22 mutant genotype, while 12 (4.4%) individuals had a heterozygous genotype and 262 (95.6%) had a wild homozygous genotype. The CYP3A5*3 allele was detected in the homozygous mutant form in 16 (5.8%) individuals, while 74 (27.0%) individuals carried the heterozygous genotype and 184 (67.2%) carried the wildtype homozygous genotype. Of the patient group, 15 (11%) were classified as intermediate metabolizers (IMs) and 133 (89%) as extensive metabolizers (EMs). Plasma simvastatin concentrations for the combined CYP3A4/5 genotypes were significantly (P<0.05) higher in the IMs group than in the EMs group. TC and plasma LDL-C levels were also significantly (P<0.05) higher in IMs than in EMs.

Conclusion

The present study showed associations between CYP3A4*22 (rs35599367) and CYP3A5*3 (rs776746) SNP combination genotypes with response to statins in hypercholesterolemia. Patients who had either a mutant homozygous allele for CYP3A5*3 or mutant homozygous and heterozygous alleles for CYP3A4*22 showed increased response to lower TC and LDL-C levels.

Novel therapeutics in hypertriglyceridaemia and chylomicronaemia

Currently there is evidence on hypertriglyceridaemia as an independent risk factor of atherosclerosis. Chylomicronaemia associated with very high concentration of triglycerides may cause severe and recurrent acute pancreatitis. The cause of most cases is a combination of a polygenetic basis with some lifestyles and pathological conditions. Some rare and familial chylomicronaemias are mendelian diseases with an autosomal recessive pattern. On the other hand, plasma triglycerides have considerable biological variability and usually descend with non-pharmacological interventions alone. In some cases, drugs are also required for their control, but their impact on vascular risk reduction or pancreatitis prevention is more controversial. The recent advances in knowledge of molecular lipid metabolism and pharmacological technologies are resulting in the development of new therapeutic strategies, which can be applied to patients with refractory hypertrigliceridaemia. The challenge may be how the health systems can cover its high costs.

Physical activity evaluation in Yugoslav Study of the Precursors of Atherosclerosis in School Children - YUSAD study

INTRODUCTION

It is observed that there is a lack of physical activity and exercise in children, stressing higher prevalence of childhood obesity. The purpose of the study was to evaluate duration of physical activity in a child population and correlation of dynamics in physical activity during 5 years of follow-up in the same population.

MATERIAL AND METHODS

We evaluated 3243 school children from 12 regional centres across Serbia. The first examination was done when the children were 10 years old (baseline group), while the second examination was done on the same population when children were 15 years old. Physical activity was classified as recreational activity after school. We analysed 3 groups regarding physical activity: a group of children who were physically active less than 1 hour per day (group I), a second group active from 1 hour to < 3 hours per day (group II), and a third group active ≥ 3 hours per day (group III).

RESULTS

In our study we have found on examination that the majority of children were physically active between 1 and 3 hours per day. Our results indicate that there is significant movement from groups I and III toward group II on the second examination regarding the proportion in the baseline group. There is a significant increase in the number of children in group I as they get older.

CONCLUSIONS

School children in Serbia are physically active predominantly between 1 and 3 hours per day at the age between 10 and 15 years.