Hypertriglyceridemia is associated with insulin levels in adult cystic fibrosis patients

Alterations in lipids after initiation of highly effective modulators in people with cystic fibrosis

Risk of cardiovascular disease (CVD) may be changing in people with cystic fibrosis (pwCF) with widespread use of highly effective modulator therapy (HEMT). We performed a retrospective analysis of patients who had lipids checked before and after initiation of ivacaftor or elexacaftor/tezacaftor/ivacaftor. We hypothesized that HEMT negatively impacts lipids (total cholesterol [TC], low-density lipoprotein [LDL], high-density lipoprotein [HDL], TC/HDL ratio). 41 adult patients were included. Paired t-tests showed statistically significant increases in TC (mean difference 16.3 mg/dL, p = 0.007, n = 40), LDL (mean difference 17.1 mg/dL, p < 0.001, n = 35), and TC/HDL ratio (mean difference 0.40, p = 0.014, n = 39) after HEMT initiation. HDL was unchanged (mean difference -1.5 mg/dL, p = 0.69, n = 39). Linear mixed models showed CF liver disease was associated with significantly blunted changes in TC and LDL. Family history of CVD risk factors was associated with significantly accentuated increases in TC and LDL. These data suggest a role for more lipid screening in pwCF.

Lipidomic alterations in human saliva from cystic fibrosis patients

Cystic fibrosis is a hereditary metabolic disorder characterized by impaired traffic of chloride ions and water through membranes of the respiratory and gastrointestinal, that causes inadequate hydration of airway surfaces, dehydrated mucous secretions and a high-sodium chloride sweat. Although the classical presentation of the condition is well known, a better characterization of metabolic alterations related is need. In particular, the metabolic composition alterations of biological fluids may be influence by the disease state and could be captured as putative signature to set targeted therapeutic strategies. A targeted comprehensive mass spectrometry-based platform was employed to dissect the lipid content of saliva samples form CF patients, in order to investigate alterations in the lipid metabolic homeostasis related to the pathology, chronic obstructive pulmonary disease, Pseudomonas Aeruginosa infection, pancreatic insufficiency, liver disfunction and diabetes-related complications.

Severe Genotype, Pancreatic Insufficiency and Low Dose of Pancreatic Enzymes Associate with Abnormal Serum Sterol Profile in Cystic Fibrosis

BACKGROUND

Several factors could lead to lipid disturbances observed in cystic fibrosis (CF). This study aimed to assess sterol homeostasis in CF and define potential exogenous and endogenous determinants of lipid dysregulation.

METHODS

The study involved 55 CF patients and 45 healthy subjects (HS). Sterol concentrations (μg/dL) were measured by gas chromatography/mass spectrometry. CF was characterised by lung function, pancreatic status, liver disease and diabetes coexistence, Pseudomonas aeruginosa colonisation and BMI. CFTR genotypes were classified as severe or other.

RESULTS

Campesterol and β-sitosterol concentrations were lower (p = 0.0028 and p < 0.0001, respectively) and lathosterol levels (reflecting endogenous cholesterol biosynthesis) were higher (p = 0.0016) in CF patients than in HS. Campesterol and β-sitosterol concentrations were lower in patients with a severe CFTR genotype, pancreatic insufficiency and lower pancreatic enzyme dose (lipase units/gram of fat). In multiple regression analyses, β-sitosterol and campesterol concentrations were predicted by genotype and pancreatic insufficiency, whereas cholesterol and its fractions were predicted by phytosterol concentrations, age, dose of pancreatic enzymes, nutritional status and genotype.

CONCLUSIONS

Independent determinants of lipid status suggest that malabsorption and pancreatic enzyme supplementation play a significant role in sterol abnormalities. The measurement of campesterol and β-sitosterol concentrations in CF patients may serve for the assessment of the effectiveness of pancreatic enzyme replacement therapy and/or compliance, but further research is required.

Cystic Fibrosis Related Diabetes - An Update

Cystic fibrosis (CF) is the most common life-threatening inherited condition in the Caucasian population, where mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene result in a multifactorial syndrome, with pulmonary disease representing the largest contributor to morbidity and mortality. Life expectancy has improved and the recent development of disease-modifying CFTR modulator therapies is likely to further improve survival. However, increasing life expectancy brings new challenges related to the complications of a chronic disease including an increasing prevalence of cystic fibrosis related diabetes (CFRD), itself associated with increased morbidity and early mortality. This review provides an update as regards the underlying mechanisms, investigation and management of CFRD.

Cystic Fibrosis Defective Response to Infection Involves Autophagy and Lipid Metabolism

Cystic fibrosis (CF) is a hereditary disease, with 70% of patients developing a proteinopathy related to the deletion of phenylalanine 508. CF is associated with multiple organ dysfunction, chronic inflammation, and recurrent lung infections. CF is characterized by defective autophagy, lipid metabolism, and immune response. Intracellular lipid accumulation favors microbial infection, and autophagy deficiency impairs internalized pathogen clearance. Myriocin, an inhibitor of sphingolipid synthesis, significantly reduces inflammation, promotes microbial clearance in the lungs, and induces autophagy and lipid oxidation. RNA-seq was performed in Aspergillusfumigatus-infected and myriocin-treated CF patients’ derived monocytes and in a CF bronchial epithelial cell line. Fungal clearance was also evaluated in CF monocytes. Myriocin enhanced CF patients’ monocytes killing of A. fumigatus. CF patients’ monocytes and cell line responded to infection with a profound transcriptional change; myriocin regulates genes that are involved in inflammation, autophagy, lipid storage, and metabolism, including histones and heat shock proteins whose activity is related to the response to infection. We conclude that the regulation of sphingolipid synthesis induces a metabolism drift by promoting autophagy and lipid consumption. This process is driven by a transcriptional program that corrects part of the differences between CF and control samples, therefore ameliorating the infection response and pathogen clearance in the CF cell line and in CF peripheral blood monocytes.

Dyslipidemia is not associated with the development of glucose intolerance or diabetes in cystic fibrosis

BACKGROUND

A high-fat, high-calorie diet is recommended in patients with cystic fibrosis (CF) as it improves nutritional status, respiratory health and longevity. In the general population, this diet is associated with the risk of diabetes. It is unknown whether dyslipidemic changes might contribute to the development of CF-related diabetes (CFRD).

OBJECTIVE

This study aimed to (i) characterize dyslipidemia and (ii) examine the association between dyslipidemia and development of glucose intolerance.

METHODS

Prospective observational study with serial assessments of pulmonary function, glucose tolerance, and lipid profile. Due to intrinsically low total, HDL and LDL cholesterol in patients with CF, subjects were characterized as having dyslipidemia if they had i) HDL in the lowest quartile and/or ii) hypertriglyceridemia (≥1.7 mmol/L).

RESULTS

A total of 256 patients with CF were included (age: 25.5 ± 7.7 years; BMI: 21.7 ± 3.0 kg/m2; FEV1%: 73.2 ± 22.1%; pancreatic insufficiency: 87%). Amongst these patients, 22.7% had low HDL, 9.0% had hypertriglyceridemia and 3.9% had mixed dyslipidemia. There were no differences in HbA1c (p = 0.583) or estimated insulin resistance [HOMA-IR (p = 0.206) or Stumvoll index (p = 0.397)]. Patients with hypertriglyceridemia had higher fat mass (p = 0.038) and fewer had pancreatic insufficiency. Lipid profiles were similar between subjects with CF and subjects with de novo CFRD. There was no effect of low HDL or hypertriglyceridemia on the development of CFRD over 10 years (p = 0.683).

CONCLUSION

In adult patients with CF, dyslipidemia is not associated with the risk of developing hyperglycemia or CFRD.

Overweight, obesity and significant weight gain in adult patients with cystic fibrosis association with lung function and cardiometabolic risk factors

BACKGROUND

For patients with cystic fibrosis (CF), maintaining a normal BMI is associated with better pulmonary function (FEV1) and survival. Given therapy improvements, some patients are now overweight, obese or present rapid weight gain. However, the impact of being overweight on clinical outcomes (e.g. FEV1 & metabolic complications) remains unknown.

METHODS

Baseline data from 290 adult CF patients and observational follow-up (3.5 years; n = 158) were collected. BMI categories: underweight (UW < 18.5 kg/m²), normal (NW 18.5-26.9 kg/m²), and overweight/obese (OW ≥ 27 kg/m²). Follow-up data (weight change over time): weight loss (WL>10%), stable (WS), and weight gain (WG>10%). BMI categories and follow-up data were compared to FEV1 and cardiometabolic parameters: glucose tolerance, estimated insulin resistance (IR), blood pressure (BP), and lipid profile.

RESULTS

For BMI categories, 35 patients (12.1%) were UW, 235 (81.0%) NW, and 20 (6.9%) OW. Compared to UW and NW patients, OW patients are older (p < 0.001), had less pancreatic insufficiency (p = 0.009), a higher systolic BP (p = 0.004), higher LDL (p < 0.001), and higher IR (p < 0.001). Compared to UW patients, OW patients had a better FEV1 (p < 0.001). For weight change, WL was observed in 7 patients (4.4%), WS in 134 (84.8%) and WG in 17 patients (10.8%). Compared to WL and WS patients, WG patients had a 5% increase in FEV1 accompanied by higher IR (p = 0.017) and triglycerides (p < 0.001). No differences were observed for glucose tolerance for neither BMI nor weight change.

CONCLUSION

A higher weight or weight gain over time are associated with a better FEV₁ but also some unfavorable cardiometabolic trends.

Cystic fibrosis dyslipidaemia: A cross-sectional study

BACKGROUND

The interest in cystic fibrosis (CF) dyslipidaemia as a potential risk factor for cardiovascular disease is increasing with patients' survival. This study aimed to investigate CF dyslipidaemia, its clinical correlates and links to oxidized low-density lipoprotein (oxLDL), adiponectin, and apolipoprotein E (APOE).

METHODS

This cross-sectional study assessed clinical characteristics of CF, as well as the serum lipid profile, oxLDL, adiponectin, and APOE.

RESULTS

In total, 108 CF subjects were enrolled in this study, with a median age of 22 years, BMI of 20.5 kg/m², FEV1% of 61%, of which 81% were pancreatic insufficient (PI). Healthy subjects (HS; n = 51) were in similar age. Hypocholesterolaemia occurred in 31% of CF subjects and in no HS. Hypertriglyceridaemia concerned 21% of patients (HS: 8%, p = .04), and low HDL-C 45% (HS: 6%, p < .0001). At least one of these three CF dyslipidaemia disturbances was present in 62% of CF subjects, but there were no significant differences in oxLDL, oxLDL/LDL-C ratio, adiponectin, and APOE between CF and HS groups. PI was independently associated with low total cholesterol, LDL-C, and non-high density lipoprotein cholesterol, with age and sex also modifying lipid levels. In CF (n = 42), triglycerides did not correlate with serum tumour necrosis factor α (TNF-α).

CONCLUSIONS

CF dyslipidaemia is highly prevalent and heterogenous. The lipid profile weakly associates with the clinical characteristics of CF as well as oxLDL, adiponectin, and APOE. Further research is needed, especially regarding HDL function in CF, the causes of hypertriglyceridaemia, and the value of essential fatty acid supplementation for CF dyslipidaemia.

Bile acid homeostasis in gastrointestinal and metabolic complications of cystic fibrosis

With the improved treatment of the pulmonary complications of cystic fibrosis (CF), gastrointestinal problems have become more important in the morbidity in CF. A hallmark of the gastrointestinal phenotype of CF, apart from pancreatic insufficiency, is a disruption of bile acid homeostasis. Bile acid homeostasis is important for many gastrointestinal processes including fat absorption, inflammation, microbial composition, as well as regulation of whole body energy metabolism. This review describes the impairment of bile acid homeostasis in CF, its possible consequences for gastrointestinal and metabolic complications and its potential as a target for therapy.

CFTR Deletion Confers Mitochondrial Dysfunction and Disrupts Lipid Homeostasis in Intestinal Epithelial Cells

Background: Cystic Fibrosis (CF) is a genetic disease in which the intestine exhibits oxidative and inflammatory markers. As mitochondria are the central source and the main target of reactive oxygen species, we hypothesized that cystic fibrosis transmembrane conductance regulator (CFTR) defect leads to the disruption of cellular lipid homeostasis, which contributes to mitochondrial dysfunction. Methods. Mitochondrial functions and lipid metabolism were investigated in Caco-2/15 cells with CFTR knockout (CFTR^-/-) engineered by the zinc finger nuclease technique. Experiments were performed under basal conditions and after the addition of the pro-oxidant iron-ascorbate (Fe/Asc) complex. Results. Mitochondria of intestinal cells with CFTR^-/-, spontaneously showed an altered redox homeostasis characterised by a significant decrease in the expression of PPARα and nuclear factor like 2. Consistent with these observations, 8-oxoguanine-DNA glycosylase, responsible for repair of ROS-induced DNA lesion, was weakly expressed in CFTR^-/- cells. Moreover, disturbed fatty acid β-oxidation process was evidenced by the reduced expression of CPT1 and acyl-CoA dehydrogenase long-chain in CFTR^-/- cells. The decline of mitochondrial cytochrome c and B-cell lymphoma 2 expression pointing to magnified apoptosis. Mitochondrial respiration was also affected as demonstrated by the low expression of respiratory oxidative phosphorylation (OXPHOS) complexes and a high adenosine diphosphate/adenosine triphosphate ratio. In contrast, the FAS and ACC enzymes were markedly increased, thereby indicating lipogenesis stimulation. This was associated with an augmented secretion of lipids, lipoproteins and apolipoproteins in CFTR^-/- cells. The addition of Fe/Asc worsened while butylated hydroxy toluene partially improved these processes. Conclusions: CFTR silencing results in lipid homeostasis disruption and mitochondrial dysfunction in intestinal epithelial cells. Further investigation is needed to elucidate the mechanisms underlying the marked abnormalities in response to CFTR deletion.

Technological advances shed light on left ventricular cardiac disturbances in cystic fibrosis

Cystic fibrosis (CF), the most common autosomal recessive lethal disease in Caucasians, causes chronic pulmonary disease and can lead to cor pulmonale with right ventricular dysfunction. The presence of the cystic fibrosis transmembrane conductance regulator (CFTR) in cardiac myocardia has prompted debate regarding possible defective ion channel-induced cardiomyopathy. Clinical heart disease in CF is considered rare and is restricted to case reports. It has been unclear if this is due to the lack of physiological importance of CFTR in the heart, the relatively short lifespan of those with CF, or a technical inability to detect subclinical disease. Extensive echocardiographic investigations have yielded contradictory results, leading to the dogma that left ventricular defects in CF occur secondary to lung disease. In this review, we consider why studies examining heart function in CF have not provided clarity on this topic. We then focus on data from new echocardiographic and magnetic resonance imaging technology, which are providing greater insight into cardiac function in CF and demonstrating that, in addition to secondary effects from pulmonary disease, there may be an intrinsic primary defect in the CF heart. With advancing lifespans and activity levels, understanding the risk of cardiac disease is vital to minimizing morbidity in adults with CF.

Dietary intake and lipid profile in children and adolescents with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) patients are advised to derive 35% of their daily energy intake from dietary fat. Whether this high fat intake is associated with dyslipidaemia is unknown. We described the lipid profile and dietary intake in paediatric patients with CF.

METHODS

110 fasting lipid concentrations of 110 Dutch patients with CF were studied, along with 86 measurements of dietary intake. For the total group and for boys and girls separately, the lipid profile and the dietary intake were investigated. The cross-sectional relationship between the lipid concentrations and dietary intake was determined.

RESULTS

The mean dietary fat intake was ≥35% of the total energy intake, along with a considerable consumption of saturated fat. We found lower concentrations of cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol, and increased concentrations of triglyceride and triglyceride to high-density lipoprotein cholesterol ratios. Lipid concentrations were not associated with dietary fat intake.

CONCLUSION

This study lacks variation in dietary fat intake to exclude an effect on lipid concentrations as the distribution of dietary fat intake remained constant at a high level. Elevated triglyceride concentrations and triglyceride to high-density lipoprotein cholesterol ratios suggest an increased risk of cardiovascular disease. Any negative consequences of a high dietary fat intake on the overall lipid profile later in life cannot be excluded.

Cystic fibrosis related liver disease--another black box in hepatology

Due to improved medical care, life expectancy in patients with cystic fibrosis (CF) has veritably improved over the last decades. Importantly, cystic fibrosis related liver disease (CFLD) has become one of the leading causes of morbidity and mortality in CF patients. However, CFLD might be largely underdiagnosed and diagnostic criteria need to be refined. The underlying pathomechanisms are largely unknown, and treatment strategies with proven efficacy are lacking. This review focuses on current invasive and non-invasive diagnostic standards, the current knowledge on the pathophysiology of CFLD, treatment strategies, and possible future developments.