Metabolism of cholesterol and apolipoprotein B in celiac disease

The association between adverse cardiovascular outcomes in celiac disease and the role of inflammation: Retrospective analysis using the national inpatient sample

Celiac disease (CD) is an immune-mediated disease with patients being prone to a proinflammatory state. With recent studies showing an association between adverse cardiovascular events in patients with CD, we aim to further elucidate this relationship. Furthermore, when risk-stratifying patients with cardiovascular disease (CVD), chronic inflammatory conditions such as CD are not included in these calculations. We conducted a retrospective analysis using the National Inpatient Sample database from 2016 to 2019 to investigate the relationship between CD and adverse cardiovascular events. Our secondary endpoints include examining patient demographics, underlying comorbidities, in-hospital mortality, and cost of hospitalization. In addition, we performed a subgroup analysis in the CD cohort to assess if concomitant iron deficiency anemia increased CVD. Our study aims to examine the association between atherosclerosis and inflammation and aims to be a stepping stone for future long-term randomized controlled trials for the incorporation into atherosclerotic CVD risk score stratification.

GATA4 controls regionalization of tissue immunity and commensal-driven immunopathology

There is growing recognition that regionalization of bacterial colonization and immunity along the intestinal tract has an important role in health and disease. Yet, the mechanisms underlying intestinal regionalization and its dysregulation in disease are not well understood. This study found that regional epithelial expression of the transcription factor GATA4 controls bacterial colonization and inflammatory tissue immunity in the proximal small intestine by regulating retinol metabolism and luminal IgA. Furthermore, in mice without jejunal GATA4 expression, the commensal segmented filamentous bacteria promoted pathogenic inflammatory immune responses that disrupted barrier function and increased mortality upon Citrobacter rodentium infection. In celiac disease patients, low GATA4 expression was associated with metabolic alterations, mucosal Actinobacillus, and increased IL-17 immunity. Taken together, these results reveal broad impacts of GATA4-regulated intestinal regionalization on bacterial colonization and tissue immunity, highlighting an elaborate interdependence of intestinal metabolism, immunity, and microbiota in homeostasis and disease.

Mass Spectrometric Analysis of L-carnitine and its Esters: Potential Biomarkers of Disturbances in Carnitine Homeostasis

PURPOSE

After a golden age of classic carnitine research three decades ago, the spread of mass spectrometry opened new perspectives and a much better understanding of the carnitine system is available nowadays. In the classic period, several human and animal studies were focused on various distinct physiological functions of this molecule and these revealed different aspects of carnitine homeostasis in normal and pathological conditions. Initially, the laboratory analyses were based on the classic or radioenzymatic assays, enabling only the determination of free and total carnitine levels and calculation of total carnitine esters' amount without any information on the composition of the acyl groups. The introduction of mass spectrometry allowed the measurement of free carnitine along with the specific and sensitive determination of different carnitine esters. Beyond basic research, mass spectrometry study of carnitine esters was introduced into the newborn screening program because of being capable to detect more than 30 metabolic disorders simultaneously. Furthermore, mass spectrometry measurements were performed to investigate different disease states affecting carnitine homeostasis, such as diabetes, chronic renal failure, celiac disease, cardiovascular diseases, autism spectrum disorder or inflammatory bowel diseases.

RESULTS

This article will review the recent advances in the field of carnitine research with respect to mass spectrometric analyses of acyl-carnitines in normal and various pathological states.

CONCLUSION

The growing number of publications using mass spectrometry as a tool to investigate normal physiological conditions or reveal potential biomarkers of primary and secondary carnitine deficiencies shows that this tool brought a new perspective to carnitine research.

Whole lipid profile and not only HDL cholesterol is impaired in children with coexisting type 1 diabetes and untreated celiac disease

AIMS

Low HDL cholesterol (HDL-C) levels have been described in patients with coexisting type 1 diabetes mellitus (T1DM) and celiac disease (CD). Data on other possible lipid abnormalities that could further increase cardiovascular risk in these patients are scarce and incomplete. Aim of this retrospective multicenter study was to evaluate whole lipid profiles, besides HDL-C, in children with T1DM associated with biopsy-proven CD, and to investigate the influence of age and degree of adherence to gluten-free diet (GFD) on lipid changes.

METHODS

A total of 261 children with both T1DM and CD were enrolled. Serum lipid profiles at CD diagnosis were compared with those after 1 year of GFD and with those of 224 matched children with T1DM alone. The adherence to GFD was judged by means of CD-related antibodies.

RESULTS

At CD diagnosis, children with T1DM + CD showed higher LDL cholesterol (LDL-C) compared to children with T1DM alone. Gluten withdrawal failed to normalize LDL-C levels, not even in completely adherent individuals. HbA1c values were not influenced by GFD. The youngest children were characterized at diagnosis by lower levels of total cholesterol and on treatment by a greater decrease in triglycerides levels.

CONCLUSIONS

An unfavorable lipid profile, characterized not only by low HDL-C levels but also by high LDL-C values, may increase the risk of cardiovascular disease in children with T1DM and untreated CD. Therefore, a strict gluten-free diet is mandatory in these children, especially the youngest.

Increased serum high-density lipoprotein-cholesterol concentration in celiac disease after gluten-free diet treatment correlates with body fat stores

BACKGROUND

Low high-density lipoprotein-cholesterol (HDL-C) concentration correlates with increased cardiovascular risk. A great prevalence of celiac disease (CD) was reported among patients with low HDL-C concentration, and gluten-free diet (GFD) treatment seems to normalize lipid profile. We evaluated blood lipids and body composition in 26 CD patients with low HDL-C level (<1.0 mmol/L) at diagnosis and after GFD.

STUDY

A case-control study.

METHODS

The diagnosis was based on histologic evidence of subtotal or total duodenal villous atrophy. Patients were studied before and after GFD treatment (14.2+/-1.4 mo) with biopsy-proven return to normal of the duodenal mucosa. HDL-C was enzymatically assessed after precipitation of very low-density lipoprotein and low-density lipoprotein with heparin-magnesium. Apolipoprotein (Apo)-AI level was assessed by immunoturbidimetric assay; triglycerides by an enzymatic colorimetric method. Body composition was assessed by dual-energy x-ray absorptiometry.

RESULTS

Body composition improved after GFD, with increasing body weight (P<0.05) essentially owing to increased fat mass (FM) (P<0.01), rather than fat-free mass (P=0.064). Total cholesterol and HDL-C were lower in untreated compared with treated patients (P<0.001 and P<0.0001). Apo-AI level increased significantly after GFD (1.20+/-0.22 vs. 1.46+/-0.17 g/L; P<0.0001). Apo-AI, sex, and FM were all significant determinants of HDL-C level; a positive correlation (R=0.68; P<0.0001) was found between increase in HDL-C level and in FM after GFD treatment.

CONCLUSIONS

Restoration of lipid profile in CD patients after GFD treatment may be explained by an increase in both Apo-AI secretion by intestinal cells and body fat stores.

Cholesterol Absorption and Synthesis in Pediatric Kidney, Liver, and Heart Transplant Recipients

BACKGROUND

Hypercholesterolemia after organ transplantation is common. Previously, we observed higher serum total cholesterol (TC) concentrations in our pediatric kidney than liver or heart transplant recipients. To find an explanation to the observed difference, our kidney recipients' cholesterol synthesis and absorption efficiency was compared to those of liver and heart recipients.

METHODS

Serum noncholesterol sterol ratios (10 x mmol to the mol of TC, surrogate estimates of hepatic cholesterol synthesis and intestinal absorption) were studied in 50 pediatric kidney, 25 liver and 12 heart transplant recipients without diabetes or cholestasis, and in 29 controls.

RESULTS

The kidney recipients had lower Delta-cholesterol (P=0.031), similar lathosterol and higher desmosterol ratios (markers of cholesterol synthesis) (P=0.020), and similar campesterol and sitosterol ratios (markers of cholesterol absorption) when compared to the controls. The liver recipients had lower campesterol ratios than the kidney recipients and controls (P=0.002). Glomerular filtration rates were not associated with the ratios of noncholesterol sterols. Multivariate analysis showed markers of cholesterol synthesis to be lower and absorption to be higher in the kidney than the liver or the heart transplant recipients. Weight-adjusted dosages of immunosuppressive agents were associated with some ratios of noncholesterol sterols and cholestanol though these varied between the transplant recipient groups.

CONCLUSIONS

Serum TC concentration in kidney recipients was not significantly associated with absorption efficiency or synthesis of cholesterol, though kidney transplantation was associated with low synthesis and high absorption efficiency of cholesterol. Immunosuppressive therapy with cyclosporine and methylprednisolone may modulate absorption efficiency and synthesis of cholesterol.

Celiac sprue (the great modern-day imposter)

PURPOSE OF REVIEW

To review the current epidemiological information on celiac disease and the various presentations and associated.

RECENT FINDINGS

Epidemiologic studies reveal celiac disease to be common, occurring in approx. 1% of the population. It is being diagnosed worldwide, even in developing countries. The classic mode of presentation has become less common, with diarrhea or a malabsorption syndrome as the mode of presentation in fewer than 50% of individuals. The other major modes of presentation are iron-deficiency anemia, osteoporosis, screening of family members, or incidentally at endoscopy done for dyspepsia or reflux. Neurological presentations may include peripheral neuropathy or ataxia. Arthritis is commonly found in patients with celiac disease when systematically sought. Patients often have a previous diagnosis of irritable bowel syndrome. Autoimmune diseases occur more frequently (three to ten times more) in those with celiac disease than the general population. However, this increased incidence of autoimmune diseases is not prevented by early diagnosis of celiac disease.

SUMMARY

We will review the various associated diseases/presentations of celiac disease. The heterogeneity of the symptoms can make the diagnosis challenging and certainly the great modern-day imposter.

Plasma carnitine ester profile in adult celiac disease patients maintained on long-term gluten free diet

AIM: To determine the fasting plasma carnitine ester in patients with celiac disease.

METHODS: We determined the fasting plasma carnitine ester profile using ESI triple quadrupol mass spectrometry in 33 adult patients with biopsy-confirmed maturity onset celiac disease maintained on long term gluten free diet.

RESULTS: The level of free carnitine did not differ as the celiac disease patients were compared with the healthy controls, whereas the acetylcarnitine level was markedly reduced (4.703 ± 0.205 vs 10.227 ± 0.368 nmol/mL, P<0.01). The level of propionylcarnitine was 61.5%, butyrylcarnitine 56.9%, hexanoylcarnitine 75%, octanoylcarnitine 71.1%, octenoylcarnitine 52.1%, decanoylcarnitine 73.1%, cecenoylcarnitine 58.3%, lauroylcarnitine 61.5%, miristoylcarnitine 66.7%, miristoleylcarnitine 62.5% and oleylcarnitine 81.1% in the celiac disease patients compared to the control values, respectively (P<0.01).

CONCLUSION: The marked decrease of circulating acetylcarnitine with 50-80 % decrease of 11 other carnitine esters shows that the carnitine ester metabolism can be influenced even in clinically asymptomatic and well being adult celiac disease patients, and gluten withdrawal alone does not necessarily normalize all elements of the disturbed carnitine homeostasis.

Cholesterol precursors and plant sterols in children with food allergy

BACKGROUND

The data on lipid metabolism in allergic children is limited.

OBJECTIVE

We investigated lipid and sterol metabolism in young children whose diets were restricted because of food allergy.

DESIGN

Children in group A [n = 21; mean (+/- SD) age: 1.78 +/- 0.73 y] were allergic to fish, eggs, and either cow milk or cereals; those in group B (n = 31, aged 1.45 +/- 0.58 y) were allergic to fish, eggs, and both cow milk and cereals. Cholesterol precursor and plant sterol to cholesterol ratios (10(2) x micro mol/mmol cholesterol) and apolipoprotein E phenotype distributions were analyzed in 36 subjects. The control group for cholesterol precursor and plant sterol measurements consisted of 18 healthy age-matched children.

RESULTS

The mean serum cholesterol concentration was 3.6 +/- 0.6 mmol/L, and HDL cholesterol was 1.03 +/- 0.3 mmol/L in group A. Corresponding values in group B were 3.4 +/- 0.7 and 1.09 +/- 0.2 mmol/L. The daily cholesterol intake was low: 61.3 +/- 36.0 mg in group A and 50.7 +/- 48.5 mg in group B. Cholesterol precursor plant sterol concentrations were significantly higher in allergic subjects than in control subjects.

CONCLUSIONS

Allergic children with restricted diets have a low intake of cholesterol and relatively low serum cholesterol concentrations. Dietary intake of plant sterols was obviously increased because of supplementation with rapeseed oil, which is rich in plant sterols, leading to elevated plant sterol concentrations. Plant sterols may have inhibited cholesterol absorption, which in turn stimulated cholesterol synthesis in compensation, also explaining the increased precursor sterol ratios in serum in our subjects.

Adaptive lipid metabolism after ileal autotransplantation in pigs with proximal gut resection

BACKGROUND

Transplantation of the small intestine impairs intestinal absorptive function, but the adaptive response of a segmental graft is unknown. The aim of this study was to investigate the effects of ileal autotransplantation on the adaptive absorption and metabolism of lipids in pigs that had undergone proximal gut resection.

METHODS

Serum lipids, plasma vitamins A and E, absorption and excretion of cholesterol, bile acids and fat, plasma cholesterol precursor and plant sterol proportions to cholesterol (respective markers of cholesterol synthesis and absorption), enteric structure, and transit were determined 4, 8, and 14 weeks after 75% proximal resection with (n = 15) or without (n = 15) autotransplantation of the remaining ileum.

RESULTS

As compared with pigs that underwent proximal gut resection, the additional autotransplantation reduced the adaptive increase in total serum and high-density lipoprotein cholesterol, plasma plant sterol proportions and vitamin E concentrations, cholesterol and fat absorption efficiency, and villus height (p < 0.05 for all) during the 14 postoperative weeks and resulted in increases of up to 4.6, 2.7, 1.3, and 2.1 times the plasma cholesterol precursors (p < 0.005), fecal excretion of bile acids (p < 0.0005), neutral steroids (p < 0.005), and net elimination of cholesterol (p < 0.0005), respectively. Cholesterol and fat absorption and plasma plant sterols were significantly enhanced between 8 and 14 weeks after autotransplantation (p < 0.05, p < 0.005, and p < 0.05, respectively), whereas fecal elimination of cholesterol remained increased until the end of the follow-up.

CONCLUSIONS

Autotransplantation of the ileum in pigs that have undergone proximal small bowel resection disturbs the adaptive absorption of cholesterol, bile acids, fat, and fat-soluble vitamins, resulting, through increased fecal elimination of cholesterol, in decreased serum cholesterol despite a marked compensatory increase in cholesterol synthesis.