Serum cholesterol level in infancy is inversely associated with subsequent allergy in children and adolescents. A 20-year follow-up study

Atopic Dermatitis and Cardiovascular Risk in Pediatric Patients: A Systematic Review and Meta-Analysis

Cardiovascular guidelines recommend early screening and preventative treatment for children with chronic inflammatory diseases. Atopic dermatitis (AD) is associated with cardiovascular risk in adults, but data in children are limited. We systematically searched for studies that examined the association between childhood AD and cardiovascular risk factors and outcomes. Data from 10 publications, including 577,148 individuals, revealed an association between AD and ischemic heart disease (n = 3, OR = 1.68, 95% confidence interval [CI] = 1.29-2.19) and diabetes (n = 4, OR = 1.31, 95% CI = 1.12-1.53), but this did not persist among studies that adjusted for potential confounders (n = 2, OR = 0.98, 95% CI = 0.35-2.75). Similarly, there was an association with lipid disorders but not across the entire population distribution (n = 7, OR = 1.24, 95% CI = 1.13-1.36, 95% prediction interval = 0.95-1.61). AD was not associated with hypertension (n = 5, OR = 1.15, 95% CI = 0.98-1.34, 95% prediction interval = 0.81-1.62) or stroke (n = 2, OR = 1.24, 95% CI = 0.94-1.62). Studies lacked detail on AD severity and important confounders such as body mass index, and the certainty of evidence was very low to low on the basis of GRADE (Grading of Recommendations, Assessment, Development and Evaluation) assessments. Currently, data do not support a clinically meaningful increase in cardiovascular risk for children with AD.

Fetal lipidome and incident risk of food allergy: A prospective birth cohort study

BACKGROUND

Lipids are proposed to be important in developing adaptive immunity and allergy. However, studies to date reported inconsistent findings.

OBJECTIVE

To examine newborn lipidome (a comprehensive profiling of circulating lipid metabolites) on child's risk of developing food allergy (FA). The maternal-cord joint effects of lipid metabolites on FA development were also investigated.

METHODS

This study included 647 mother-child pairs from the Boston Birth Cohort and analyzed 202 lipid metabolites in cord plasma profiled by liquid chromatography tandem mass spectrometry. FA was defined based on standard clinical criteria. Logistic regression was applied to examine the relationships between individual metabolites and risk of FA.

RESULTS

Of the 647 children, 61 developed FA. Cord triacylglycerols of long carbon chains and multiple double bonds were significantly associated with decreased risk of FA. These associations were comparable across strata of pertinent maternal and child covariates, and were independent of maternal triacylglycerols when assessed simultaneously. Besides, cord and maternal triacylglycerols had an additive effect in association with risk of FA: Children having high (≥Median) C56:8 triacylglycerol levels in both cord and maternal plasma were at the lowest risk of developing FA (OR = 0.24, 95% CI = 0.10-0.56, p = .001), compared to those having low levels in both cord and maternal plasma.

CONCLUSION

This is the first birth cohort study to link altered cord plasma lipidome with future risk of development FA during childhood. It calls for further investigation on triacylglycerols of long carbon chains and multiple double bonds as potential novel predictive biomarkers and therapeutic targets for FA.

Body mass index and serum lipid profile: Association with atopic dermatitis in a paediatric population

BACKGROUND/OBJECTIVES

The association between atopic dermatitis, body weight and serum lipid levels is not well known, and very few studies have examined this relationship in children.

METHODS

Children (n = 239) under 14 years old participated in this prospective cross-sectional study. The following variables were recorded: age, gender, weight, height, atopic dermatitis severity, serum levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides.

RESULTS

Mean body mass index was slightly higher in atopic dermatitis patients than healthy controls and significantly higher in atopic dermatitis patients aged 0-2 years (atopic dermatitis, 16.7 ± 4.6; controls, 15.7 ± 1.3; P = 0.04) and 12-14 years (atopic dermatitis, 24.9 ± 5.3; controls, 20.6 ± 3.4; P = 0.03). Among atopic dermatitis patients, body mass index was significantly higher in those with severe atopic dermatitis in the 9-12 (P = 0.03) and 12-14 (P = 0.01) years groups. Mean serum lipid levels were higher in patients with severe atopic dermatitis than in the atopic dermatitis group as a whole. These differences reached statistical significance for total cholesterol (P = 0.04) and triglycerides (P = 0.02).

CONCLUSION

The prevalence of overweight, obesity and dyslipidemia is greater in children with atopic dermatitis than in age-matched healthy counterparts.

Maternal triacylglycerol signature and risk of food allergy in offspring

BACKGROUND

The prevalence of IgE-mediated food allergy (FA) is increasing worldwide, but the underlying mechanisms are poorly understood.

OBJECTIVE

We sought to examine the role of maternal lipidomic profiles in risk of FA development in offspring and to investigate the potential modification effects by timing of first solid-food introduction.

METHODS

This report included 1068 mother-child dyads from the Boston Birth Cohort. Maternal lipid metabolites in plasma were assessed by using liquid chromatography tandem mass spectrometry. Food sensitization (FS) was defined as a specific IgE level of 0.35 kU/L or greater to any of the 8 common food allergens determined by using ImmunoCAP. FA was defined based on FS, clinical symptoms, and food avoidance. Logistic regression was applied to analyze associations between maternal metabolites and risk of FS and FA in offspring and to explore potential effect modifications.

RESULTS

Of the 1068 children, 411 had FS, and 132 had FA. Among the 209 metabolites, maternal triacylglycerols (TAGs) of shorter carbon chains and fewer double bonds were associated with greater risk of FA, whereas TAGs of longer carbon chains and more double bonds were significantly associated with lower risk of FA in offspring. These associations were stronger in children with delayed solid-food introduction (≥7 months of age) than those with earlier solid-food introduction (P = .010 for interaction between the maternal TAG score and timing of solid-food introduction). No significant association was found for FS.

CONCLUSION

This is the first study to demonstrate a link between maternal TAGs and risk of FA in offspring and potential risk modification by timing of solid-food introduction.

Association between Allergies and Hypercholesterolemia: A Systematic Review

BACKGROUND

There is controversy in the literature regarding the potential relationship between atopic predisposition (AP) and serum cholesterol levels. To this purpose, we reviewed human studies that investigated this possible link.

METHODS

Following PRISMA guidelines, a literature search of PubMed and Science Direct for peer-reviewed journal articles in English from January 2003, with updates through to August 2016, was conducted. Relevant publications were reviewed that included pediatric and adult populations. Information on the study design, sample, intervention, comparators, outcome, time frame, and risk of bias were abstracted for each article.

RESULTS

Of 601 reviewed reports, 18 were included in this systematic review. Fifteen studies assessed the relationship between AP and serum cholesterol levels. Due to the lack both of observational and cross-sectional studies from the literature search at this time (only 8 studies also analyzed confounding factors) there is a high possibility of confounding variables (familial and genetic predisposition, age, gender, BMI, comorbidity, and medication status) that could not be ruled out.

CONCLUSION

Existing studies are heterogeneous, making it difficult to draw broad conclusions. Future studies and more detailed analyses, considering confounding variables and including a larger and homogeneous population, are needed to strengthen the argument for a link between lipid metabolism and atopy.

Regulation of Adaptive Immunity in Health and Disease by Cholesterol Metabolism

Four decades ago, it was observed that stimulation of T cells induces rapid changes in cellular cholesterol that are required before proliferation can commence. Investigators returning to this phenomenon have finally revealed its molecular underpinnings. Cholesterol trafficking and its dysregulation are now also recognized to strongly influence dendritic cell function, T cell polarization, and antibody responses. In this review, the state of the literature is reviewed on how cholesterol and its trafficking regulate the cells of the adaptive immune response and in vivo disease phenotypes of dysregulated adaptive immunity, including allergy, asthma, and autoimmune disease. Emerging evidence supporting a potential role for statins and other lipid-targeted therapies in the treatment of these diseases is presented. Just as vascular biologists have embraced immunity in the pathogenesis and treatment of atherosclerosis, so should basic and clinical immunologists in allergy, pulmonology, and other disciplines seek to encompass a basic understanding of lipid science.

Reciprocal interference of experimental dyslipidemia and food allergy in the evolution of both diseases

Background. Food allergies have been shown to reduce serum triacylglycerol, glucose, cholesterol, and free fatty acid levels in mice. In turn, dyslipidemias, especially dyslipidemias presenting with low levels of HDL cholesterol, are important risk factors for the development of atherosclerosis. However, the consequences of food allergies on dyslipidemia and atherosclerosis have not been fully investigated. Methods. Food allergy was induced using an egg white solution (EWS) in ovalbumin- (OVA-) sensitized C57BL/6 and low-density lipoprotein receptor knockout mice (LDLr^−/−) for 5 weeks and was confirmed by the high production of anti-OVA IgE and IgG1 antibodies in both mouse strains. Results. The allergic C57BL/6 mice exhibited EWS aversion that was associated with less visceral fat and high levels of anti-Ova IgE antibodies after 5 weeks of EWS intake compared to controls. However, LDLr^−/− allergic mice showed reduced anti-Ova IgE levels that were similar to the nonsensitized group. The LDLr^−/− allergic mice also demonstrated a reversal of food aversion and sustained visceral fat after 5 weeks of allergy. Although HDL cholesterol levels were reduced in both sensitized mouse strains, lipid deposition in thoracic and abdominal aorta as well as area and composition of atherosclerotic plaques as unaffected by chronic ingestion of EWS. Conclusion. LDLr^−/− mice develop an attenuated food allergy, as they showed a reversal of food aversion and lower IgE production after 5 weeks of induced allergy. The development of atherosclerosis, in turn, was not accelerated in the allergic LDLr^−/− group despite the more atherogenic lipid profile.

Relationship of serum cholesterol levels to atopy in the US population

BACKGROUND

Cholesterol promotes Th2 immunity and allergic inflammation in rodents; whether this occurs in humans is unclear. Reports of both direct and inverse associations between serum cholesterol and atopy in different populations suggest that race and/or other demographic variables may modify these relationships.

AIMS OF THE STUDY

To determine the relationships between levels of three serum cholesterol measures [total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), and non-HDL-C] and atopy in a sample representative of the US population.

METHODS

Cross-sectional study of 6854 participants aged > or =6 years from the 2005-2006 National Health and Nutrition Examination Survey.

RESULTS

In the overall population, adjusted odds ratios (AORs) per two-standard deviation increase in TC and non-HDL-C for biochemical atopy (defined as > or =1 allergen-specific IgE to 19 allergens) were 1.17 [95% confidence interval (CI), 1.00-1.38] and 1.19 (95% CI, 1.03-1.39), respectively. Interactions by race were noted for the two relationships (interaction P = 0.004 and P = 0.009, respectively) with non-Hispanic Whites (NHWs) having direct relationships [TC: AOR 1.27 (95% CI, 1.03-1.57); non-HDL-C: AOR 1.27 (95% CI, 1.03-1.56)] and non-Hispanic Blacks (NHBs) inverse relationships [TC: AOR 0.77 (95% CI, 0.62-0.95); non-HDL-C: AOR 0.86 (95% CI, 0.69-1.08)]. The adjusted HDL-C-atopy relationship was nonsignificant for NHWs and inverse for NHBs [AOR 0.77 (95% CI, 0.61-0.96)]. Relationships were independent of body mass index and serum C-reactive protein and unmodified by corticosteroid or statin usage. Results were similar using current hay fever/allergy as the atopy outcome.

CONCLUSIONS

There are marked inter-racial differences in the relationship between serum cholesterol and atopy in the US population.