Nutritional Global Status and Its Impact in Crohn's Disease

Bone health in patients with inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) are prone to reduced bone mineral density and elevated overall fracture risk. Osteopenia affects up to 40% of patients with IBD (high regional variability). Besides disease activity, IBD specialists must consider possible side effects of medication and the presence of associated diseases and extraintestinal manifestations. Osteopenia and osteoporosis remain frequent problems in patients with IBD and are often underestimated because of widely differing screening and treatment practices. Malnutrition, chronic intestinal inflammation and corticosteroid intake are the major pathophysiological factors contributing to osteoporosis. Patients with IBD are screened for osteoporosis using dual-energy X-ray absorptiometry (DXA), which is recommended for all patients with a prolonged disease course of more than three months, with repeated corticosteroid administration, aged >40 years with a high FRAX risk score or aged <40 years with multiple risk factors. From a therapeutic perspective, besides good disease control, vitamin D supplementation and glucocorticoid sparing, several specific osteological options are available: bisphosphonates, receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors (denosumab), parathyroid hormone (PTH) analogues and selective estrogen receptor modulators. This review provides an overview of the pathophysiology, diagnosis, prevention and treatment of IBD-associated bone loss.

Identification of differentially expressed genes associated with ferroptosis in Crohn's disease

Ferroptosis-related genes may play a critical regulatory role in the pathogenesis of Crohn's disease (CD). The purpose of the present study was to identify genes expressed in CD that are associated with ferroptosis, and to provide guidance in the diagnosis and therapy of CD. CD mRNA expression data were initially gathered from the Gene Expression Omnibus (GEO) database. GSE75214 and GSE102133 datasets were selected as the major targets and were analyzed for differentially expressed genes (DEGs). Subsequently, R software was used to analyze the common genes among the DEGs between CD and ferroptosis-related genes. Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genome pathway analysis were conducted to identify related pathways and functions. Protein-protein interaction (PPI) analysis was performed to identify target genes. The DSigDB website was used to predict potential target drugs for hub genes. Reverse transcription-quantitative (RT-q) PCR was employed to detect the expression of these ferroptosis-related genes in clinical samples obtained from healthy controls and patients with CD. According to the two GEO datasets, 13 ferroptosis DEGs (11 upregulated genes and two downregulated genes) were identified in CD with thresholds of P<0.05 and |log2 fold change|>1, and were selected for further analysis. PPI analysis indicated the mutual effects among these genes and filtered out five hub genes. The top 10 potential targeted drugs were selected. The qPCR results showed that the expression levels of three genes, namely, IL-6, prostaglandin-endoperoxide synthase 2 (PTGS2) and dual oxidase 2 (DUOX2), were different between CD samples and healthy samples. This result was consistent with the results obtained from the bioinformatics analysis. In conclusion, bioinformatics analysis identified a total of 13 ferroptosis-associated genes in CD. Further verification by qPCR showed that IL-6, PTGS2 and DUOX2 may affect the process of CD by regulating ferroptosis. These findings might provide new biomarkers, diagnostic and therapeutic markers for CD.

Intestinal Oxalate Absorption, Enteric Hyperoxaluria, and Risk of Urinary Stone Formation in Patients with Crohn's Disease

Nephrolithiasis is a common urologic manifestation of Crohn's disease. The purpose of this study was to investigate the clinical characteristics, intestinal oxalate absorption, and risk factors for urinary stone formation in these patients. In total, 27 patients with Crohn's disease and 27 healthy subjects were included in the present study. Anthropometric, clinical, and 24 h urinary parameters were determined, and the [13C2]oxalate absorption test was performed. Among all patients, 18 had undergone ileal resection, 9 of whom had a history of urinary stones. Compared to healthy controls, the urinary excretion values of calcium, magnesium, potassium, sulfate, creatinine, and citrate were significantly lower in patients with Crohn's disease. Intestinal oxalate absorption, the fractional and 24 h urinary oxalate excretion, and the risk of calcium oxalate stone formation were significantly higher in patients with urolithiasis than in patients without urolithiasis or in healthy controls. Regardless of the group, between 83% and 96% of the [13C2]oxalate was detected in the urine within the first 12 h after ingestion. The length of ileum resection correlated significantly with the intestinal absorption and urinary excretion of oxalate. These findings suggest that enteric hyperoxaluria can be attributed to the hyperabsorption of oxalate following extensive ileal resection. Oral supplementation of calcium and magnesium, as well as alkali citrate therapy, should be considered as treatment options for urolithiasis.

Vitamin D levels in the assessment of Crohn's disease activity and their relation to nutritional status and inflammation

BACKGROUND

Crohn's disease (CD) is frequently associated with malnutrition, inflammation and a deficiency of vitamin D (VD) with the relationships between these symptoms being poorly defined. VD is a modulator of the immune system and is associated with the onset of CD and disease activity. The level of serum VD may have potential in the assessment of CD activity. This study aimed to evaluate the relationships between VD, nutritional status and inflammation, and to identify more accurate VD thresholds.

METHODS

The study included 76 outpatients with CD diagnosed between October 2018 and October 2020 and 76 healthy volunteers. Levels of serum 25(OH)D and nutritional indicators, as well as biochemical and disease activity assessments, were conducted.

RESULTS

Patients with CD and healthy participants were found to differ significantly in their 25(OH)D levels as well in levels of nutritional and inflammatory indicators. The optimal VD cut-off value was found to be 46.81 nmol/L for CD development and 35.32 nmol/L for disease activity. Levels of 25(OH)D were correlated with both nutritional status and inflammation.

CONCLUSIONS

The VD level is likely to be a useful additional tool in the evaluation of CD patients and predicting the disease activity and clinical response. The VD level may relate both to the nutritional status and levels of inflammation in CD patients, and disease progression.

Joint Detection of Serum Vitamin D, Body Mass Index, and Tumor Necrosis Factor Alpha for the Diagnosis of Crohn's Disease

OBJECTIVE

Vitamin D (VD) deficiency was reported to contribute to the progression of Crohn's disease (CD) and affect the prognosis of CD patients. This study investigated the role of serum VD, body mass index (BMI), and tumor necrosis factor alpha (TNF-α) in the diagnosis of Crohn's disease.

METHODS

CD patients (n=76) and healthy subjects (n=76) were enrolled between May 2019 and December 2020. The serum 25-hydroxyvitamin D [25(OH)D] levels, BMI, and TNF-α levels, together with other biochemical parameters, were assessed before treatment. The diagnostic efficacy of the single and joint detection of serum 25(OH)D, BMI, and TNF-α was determined using receiver operating characteristic (ROC) curves.

RESULTS

The levels of 25(OH) D, BMI, and nutritional indicators, including hemoglobin, total protein, albumin, and high-density lipoprotein cholesterol, were much lower, and the TNF-α levels were much higher in the CD patients than in the healthy subjects (P<0.05 for all). The areas under the ROC curve for the single detection of 25(OH)D, BMI, and TNF-α were 0.887, 0.896, and 0.838, respectively, with the optimal cutoff values being 20.64 ng/mL, 19.77 kg/m², and 6.85 fmol/mL, respectively. The diagnostic efficacy of the joint detection of 25(OH)D, BMI, and TNF-α was the highest, with an area under the ROC curve of 0.988 (95%CI: 0.968-1.000).

CONCLUSION

The joint detection of 25(OH)D, TNF-α, and BMI showed high sensitivity, specificity, and accuracy in CD diagnosis; thus, it would be effective for the diagnosis of CD in clinical practice.

Imaging-based assessment of body composition in patients with Crohn's disease: a systematic review

BACKGROUND AND AIMS

Body composition changes in patients with Crohn's disease (CD) have received increasing attention in recent years. This review aims to describe the changes in body composition in patients with CD on imaging and to analyze and summarize the prognostic value of body composition.

METHODS

We systematically searched Web of Science, PubMed, Embase, Cochrane Library, and Medline via OVID for literature published before November 2022, and two researchers independently evaluated the quality of the retrieved literature.

RESULTS

A total of 39 publications (32 cohort studies and 7 cross-sectional studies) involving 4219 patients with CD were retrieved. Imaging methods for body composition assessment, including dual-energy X-ray absorptiometry (DXA), computed tomography (CT) and magnetic resonance imaging (MRI), were included in this review. The study found that patients with CD typically have more visceral adipose tissue and less skeletal muscle mass, and the prevalence of sarcopenia and visceral obesity was significantly different in different studies (sarcopenia: 16-100%; visceral obesity: 5.3-30.5%). Available studies suggest that changes in the body composition of CD patients are significantly related to inflammatory status, disease behavior, poor outcomes, and drug efficacy.

CONCLUSION

Altered body composition can be a significant predictor of poor outcomes for CD patients. Therefore, the body composition of CD patients may serve as a potential therapeutic target to help optimize disease management strategies in clinical practice.

Inflammation and malnutrition in inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, has become increasingly prevalent worldwide in the past decade. The nutritional status of patients with IBD is often impaired, with malnutrition presenting as imbalanced energy or nutrient intake, including protein-energy malnutrition, disease-related malnutrition, sarcopenia, and micronutrient deficiency. Additionally, malnutrition can manifest as overweight, obesity, and sarcopenic obesity. Malnutrition can lead to disturbances in gut microbiome composition that might alter homoeostasis and cause a dysbiotic state, potentially triggering inflammatory responses. Despite the clear link between IBD and malnutrition, little is known about the pathophysiological mechanisms beyond protein-energy malnutrition and micronutrient deficiencies that could promote inflammation through malnutrition, and vice versa. This Review focuses on potential mechanisms that trigger a vicious cycle between malnutrition and inflammation, and their clinical and therapeutic implications.