Inadequate sunlight exposure in patients with inflammatory bowel disease

Causal association between common rheumatic diseases and glaucoma: a Mendelian randomization study

Background

Autoimmunity and inflammation are the main characteristics of rheumatic diseases and have both been found to be related to glaucoma. However, it remains unclear whether rheumatic diseases increase the risk of glaucoma. Here, we performed a Mendelian randomization (MR) analysis to investigate the causal effects of six common rheumatic diseases on glaucoma.

Methods

Six rheumatic diseases were included: ankylosing spondylitis (AS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), Sicca syndrome/Sjögren's sydrome (SS), dermatomyositis (DM), and gout. Glaucoma included primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). Genetic variants associated with these rheumatic diseases and glaucoma were extracted from the genome-wide association studies and FinnGen8 database, respectively. First, a two-sample MR was used to investigate the potential causal association. Then, a multivariable MR was conducted to further verify the results. Inverse-variance weighted MR analysis was used as the main method, together with several sensitivity analyses.

Results

Two-sample MR suggests that AS is related to a higher risk of both POAG [odds ratio (OR): 1.28, 95% confidence interval (CI) 1.13-1.44; p = 1.1 × 10-4] and PACG (OR: 1.55, 95% CI: 1.09-2.09, p = 1.4 × 10-2). Multivariable MR shows a similar trend of the effect of AS on POAG (OR: 1.52, 95% CI: 1.22-1.90, p = 1.9 × 10-4) and PACG (OR: 2.05, 95% CI: 1.06-3.95, p = 3.2 × 10-2). No significant association was observed between the other five rheumatic diseases and glaucoma.

Conclusions

AS is related to an increased risk of POAG and PACG. We stress the importance of glaucoma screening for AS patients.

Immunomodulatory actions of vitamin D in various immune-related disorders: a comprehensive review

For many years, vitamin D has been acknowledged for its role in maintaining calcium and phosphate balance. However, in recent years, research has assessed its immunomodulatory role and come up with conflicting conclusions. Because the vitamin D receptor is expressed in a variety of immune cell types, study into the precise role of this molecule in diseases, notably autoimmune disorders, has been made possible. The physiologically activated version of vitamin D also promotes a tolerogenic immunological condition in addition to modulating innate and acquired immune cell responses. According to a number of recent studies, this important micronutrient plays a complex role in numerous biochemical pathways in the immune system and disorders that are associated with them. Research in this field is still relatively new, and some studies claim that patients with severe autoimmune illnesses frequently have vitamin D deficiencies or insufficiencies. This review seeks to clarify the most recent research on vitamin D's immune system-related roles, including the pathophysiology of major disorders.

Low Vitamin K and Vitamin D Dietary Intake in Patients with Inflammatory Bowel Diseases

The inadequate dietary intake of Vitamin D and Vitamin K is an easily reversible factor favoring IBD-associated bone loss, but data on Vitamin K are lacking. A 28-item quantitative food frequency questionnaire was administered to 193 IBD patients (89 Crohn’s disease and 104 ulcerative colitis), and 199 controls. Patients’ demographics, clinical and laboratory findings were analyzed in relation to recommended daily allowances. VitD intake was inadequate both in the IBD and control patients (8.3 ± 4.5 µg/day in IBD, 53.1% RDA, and 9.7 ± 5.9 µg/day, 63.2% RDA, respectively). Conversely, the mean ViK intake was less than adequate in IBD, at 116.7 ± 116.3 µg/day (78.7% RDA), and high in controls, at 203.1 ± 166.9 µg/day (138.8% RDA). Nonetheless, due to marked inter-individual differences, diets were severely lacking VitK in 40% of UC and 49% of CD patients, more so in females and those with active disease. The intake of Vit D was non-significantly lower in colitis than that in Crohn’s disease (7.9 vs. 8.7 µg/day). The opposite was observed for VitK (123.5 vs. 107.0 µg/day). Thus, the diet lacks the micronutrients involved in bone wellbeing in a large proportion of IBD patients. While VitD supplementation is the rule, VitK shortages need proactive nutritional intervention.

Association between Inflammatory Bowel Disease and Iridocyclitis: A Mendelian Randomization Study

BACKGROUND

Iridocyclitis (IC) is a common extraintestinal manifestation of inflammatory bowel disease (IBD). Observational studies showed patients with ulcerative colitis (UC) and Crohn's disease (CD) both have a higher risk of IC. However, due to the inherent limitations of observational studies, the association and its directionality between the two forms of IBD and IC remain undiscerned.

METHODS

Genetic variants for IBD and IC were selected as instruments from genome-wide association studies (GWAS) and FinnGen database as instrumental variables, respectively. A bidirectional Mendelian randomization (MR) and multivariable MR were performed successively. Three different MR methods were performed to determine the causal association, including inverse-variance weighted (IVW), MR Egger, and weighted median, whereas IVW was used as the main analysis. Different methods for sensitivity analysis were used, including MR-Egger intercept test, MR Pleiotropy RESidual Sum and Outlier test, Cochran's Q test, and leave-one-out analysis.

RESULTS

Bidirectional MR suggested both UC and CD were positively associated with IC as a whole, acute and subacute IC, and chronic IC. However, in the MVMR analysis, only the association from CD to IC remained stable. In the reverse analysis, no association was observed from IC to UC or CD.

CONCLUSIONS

Both UC and CD are associated with an increased risk of IC compared with healthy individuals. However, the association between CD and IC is stronger. In the reverse direction, patients with IC do not suffer a higher risk of UC or CD. We emphasize the importance of ophthalmic examinations for IBD patients, especially for CD patients.

Nutrition in inflammatory bowel diseases; Is there a role?

Nutrition is of paramount importance not only for healthy individuals, but all the more for the ones with pathologies interlinked with the diet. In that light, diet, when used accordingly can act in a protective manner in inflammatory bowel diseases. The interplay of diet and IBD is not thoroughly defined, and guidelines are a work in progress. However, significant knowledge has been gained with regard to foods and nutrients that may exacerbate or alleviate the core symptoms. Patients with IBD restrict from their diet a plethora of foods often arbitrary, thus depriving themselves from valuable constituents. Careful navigation into the newfound field of genetic variants and personalization of diet should be employed with avoidance of the Westernized diet, processed foods and additives, and focus on a holistic approach with a balanced diet rich in bioactive compounds in order to improve the quality of life of these patients and address diet-related deficiencies.

Association between vitamin D level and pediatric inflammatory bowel disease: A systematic review and meta-analysis

Background

Previous studies have reported that the incidence of pediatric inflammatory bowel disease (IBD) is related to vitamin D, but it is still unclear. This study intends to calculate the relationship between pediatric IBD and vitamin D.

Methods

A comprehensive literature search from inception to January 2023 was performed in the PubMed, EMBASE, Medline, Web of Science, and Google Scholar databases. Relevant data were extracted as required and used for subsequent calculations.

Results

Sixteen papers were included, and there was no significant difference between the average vitamin D level in IBD patients and healthy controls. In addition, the overall pooled results showed that C-reactive protein (CRP) was 2.65 higher before vitamin D supplementation than after supplementation [SMD = 2.65, 95% CI = (2.26, 3.04)]. Moreover, patients with IBD in remission were 0.72 higher before vitamin D supplementation than after supplementation [OR = 0.72, 95% CI = (0.52, 1.00)].

Conclusion

This study suggested that there was no obvious relationship between pediatric IBD and vitamin D, while vitamin D supplementation can improve disease activity. Therefore, follow-up still needs many prospective studies to confirm the relationship between pediatric IBD and vitamin D.

Vitamin D in Inflammatory Bowel Diseases. Mechanisms of Action and Therapeutic Implications

(1) Background: Vitamin D is an immunoregulatory factor influencing intestinal homeostasis. Recent evidence supports a central role of this micronutrient in the course of Inflammatory Bowel Diseases (IBD). This narrative review aims to provide a general overview of the possible biological mechanisms of action of vitamin D and its therapeutic implications in IBD. (2) Methods: A systematic electronic search of the English literature up to October 2021 was performed using Medline and the Cochrane Library. Only papers written in English that analyzed the role of vitamin D in IBD were included. (3) Results: In vitro and animal studies reported that vitamin D signaling improves epithelial barrier integrity regulating the expression of several junctional proteins, defensins, and mucins, modulates the inflammatory response, and affects gut microbiome composition. Recent studies also suggest that vitamin D deficiency is highly prevalent among IBD patients and that low serum levels correlate with disease activity and, less clearly, with disease course. (4) Conclusions: An increasing body of evidence suggests some role of vitamin D in the pathophysiology of IBD, nonetheless the underlying mechanisms have been so far only partially elucidated. A strong correlation with disease activity has been reported but its implication in the treatment is still undefined. Thus, studies focused on this issue, the definition of vitamin D levels responsible for clinical effects, and the potential role of vitamin D as a therapeutic agent are strongly encouraged.

Prevalence of Inflammatory Bowel Disease in Pediatric and Adult Populations: Recent Estimates From Large National Databases in the United States, 2007-2016

BACKGROUND

The latest estimate of the prevalence of inflammatory bowel disease (IBD) in the United States was based on 2009 data, which indicates a need for an up-to-date re-estimation. The objectives of this study were to investigate the prevalence of all forms of IBD including ulcerative colitis (UC), Crohn's disease (CD), and IBD unspecified (IBDU).

METHODS

Pediatric (age 2-17) and adult (age ≥18) IBD patients were identified from 2 large claims databases. For each year between 2007 and 2016, prevalence was calculated per 100,000 population and standardized based on the 2016 national Census. A fixed-effects meta-analytical model was used for overall prevalence.

RESULTS

The pediatric prevalence of IBD overall increased by 133%, from 33.0/100,000 in 2007 to 77.0/100,000 in 2016. Among children, CD was twice as prevalent as UC (45.9 vs 21.6). Prevalence was higher in boys than girls for all forms of IBD, in contrast to the adult population where the prevalence was higher in women than men. We also found that the 10-17 age subgroup was the major contributor to the rising pediatric IBD prevalence. For adults, the prevalence of IBD overall increased by 123%, from 214.9 in 2007 to 478.4 in 2016. The prevalence rates of UC and CD were similar (181.1 vs 197.7) in 2016.

CONCLUSIONS

Inflammatory bowel disease continues to affect a substantial proportion of the US population. In 2016, 1 in 209 adults and 1 in 1299 children aged 2-17 were affected by IBD. Prevalence of IBD has been increasing compared with previously published 2009 data.

Vitamin D in Inflammatory Bowel Disease: Biological, Clinical and Therapeutic Aspects

BACKGROUND

Vitamin D has an immunoregulatory action in Inflammatory Bowel Disease (IBD) as well as other immune-mediated disorders. Its influence on intestinal permeability, innate and adaptive immunity, and the composition and diversity of the microbiota contribute to the maintenance of intestinal homeostasis. Patients with IBD have a greater prevalence of vitamin D deficiency than the general population, and a possible association between this deficit and a worse course of the disease. However, intervention studies in patients with IBD have proved inconclusive.

OBJECTIVE

To review all the evidence concerning the role of vitamin D as an important factor in the pathophysiology of IBD, review the associations found between its deficiency and the prognosis of the disease, and draw conclusions for the practical application from the main intervention studies undertaken.

METHODS

Structured search and review of basic, epidemiological, clinical and intervention studies evaluating the influence of vitamin D in IBD, following the basic principles of scientific data.

RESULTS

Vitamin D deficiency is associated with disease activity, quality of life, the consumption of social and healthcare resources, and the durability of anti-TNFα biological treatment. Determination of new metabolites of vitamin D, measurement of its absorption capacity and questionnaires about sun exposure could help identify groups of IBD patients with a special risk of vitamin D deficiency.

CONCLUSION

Well-designed intervention studies are needed in IBD, with probably higher objective plasma doses of vitamin D to establish its efficacy as a therapeutic agent with immunomodulatory properties. Meanwhile, vitamin D deficiency should be screened for and corrected in affected patients in order to achieve adequate bone and phosphocalcic metabolism.

Skin Exposure to Narrow Band Ultraviolet (UVB) Light Modulates the Human Intestinal Microbiome

The recent worldwide rise in idiopathic immune and inflammatory diseases such as multiple sclerosis (MS) and inflammatory bowel diseases (IBD) has been linked to Western society-based changes in lifestyle and environment. These include decreased exposure to sunlight/UVB light and subsequent impairment in the production of vitamin D, as well as dysbiotic changes in the makeup of the gut microbiome. Despite their association, it is unclear if there are any direct links between UVB light and the gut microbiome. In this study we investigated whether exposing the skin to Narrow Band Ultraviolet B (NB-UVB) light to increase serum vitamin D levels would also modulate the makeup of the human intestinal microbiota. The effects of NB-UVB light were studied in a clinical pilot study using a healthy human female cohort (n = 21). Participants were divided into those that took vitamin D supplements throughout the winter prior to the start of the study (VDS+) and those who did not (VDS−). After three NB-UVB light exposures within the same week, the serum 25(OH)D levels of participants increased on average 7.3 nmol/L. The serum response was negatively correlated to the starting 25-hydroxy vitamin D [25(OH)D] serum concentration. Fecal microbiota composition analysis using 16S rRNA sequencing showed that exposure to NB-UVB significantly increased alpha and beta diversity in the VDS− group whereas there were no changes in the VDS+ group. Bacteria from several families were enriched in the VDS− group after the UVB exposures according to a Linear Discriminant Analysis (LDA) prediction, including Lachnospiracheae, Rikenellaceae, Desulfobacteraceae, Clostridiales vadinBB60 group, Clostridia Family XIII, Coriobacteriaceae, Marinifilaceae, and Ruminococcus. The serum 25(OH)D concentrations showed a correlation with the relative abundance of the Lachnospiraceae, specifically members of the Lachnopsira and Fusicatenibacter genera. This is the first study to show that humans with low 25(OH)D serum levels display overt changes in their intestinal microbiome in response to NB-UVB skin exposure and increases in 25(OH)D levels, suggesting the existence of a novel skin-gut axis that could be used to promote intestinal homeostasis and health.

Clinical Trial Registration:clinicaltrials.gov, NCT03962673. Registered 23 May 2019 – Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03962673?term=NCT03962673&rank=1.

Vitamin D in inflammatory bowel disease: From biology to clinical implications

Inflammatory bowel disease (IBD) is a chronic immune-mediated inflammatory disorder of the gastrointestinal tract consisting two principal categories, ulcerative colitis (UC) and Crohn's disease (CD). The precise etiology of IBD remains unknown. Vitamin D is an important micronutrient that plays a critical biological role in various processes in human tissues. However, the relationship between disruption of the gut microbiota and the development of IBD is unclear. Some studies suggest that IBD is the cause of disrupted gut microbiota while others propose that gut microbiota itself can lead to development of IBD. Regardless of this complexity, it has emerged that vitamin D is an immunoregulatory factor that plays a significant role in the pathogenesis of IBD by affecting the gut microbiome and the inflammatory response. It has been reported that 38.1% of CD patients and 31.6% of UC patients suffer from vitamin D deficiency (VDD). In this review, we aimed to evaluate the association between VDD and IBD, summarizing recent clinical studies examining the effect of low vitamin D and the role of vitamin D supplementation on IBD clinical outcomes.

Sunlight exposure in inflammatory bowel disease outpatients: Predictive factors and correlation with serum vitaminD

INTRODUCTION

Sunlight exposure is the main source of vitaminD. Our aim was to describe both sun exposure and sun protection behaviour in a series of patients with inflammatory bowel disease (IBD), and to study their potential association with vitaminD concentration.

PATIENTS AND METHODS

A cross sectional, observational study. The clinical-demographic variables were obtained via clinical interviews and medical history review. The sunlight exposure assessment was carried out using the Sun Exposure Questionnaire and the concentration of 25-hydroxy vitaminD (25OHD) was measured by an electro-chemiluminescence immunoassay. Questionnaires were conducted on quality of life, physical activity, weekly vitaminD intake and sun protection behaviour.

RESULTS

149 patients were included. In 69% of patients, deficient or insufficient 25OHD values were recorded. 67% showed low sun exposure. A modest significant correlation was observed between the total score of the solar exposure questionnaire and the 25OHD concentration in the complete series (r=0.226, P=.006) and in the summer (r=0.274, P=.01). The sun protection behaviour questionnaire score did not influence the 25OHD concentration. In the multivariate analysis, only the presence of clinical activity was associated with low sun exposure (OR=3.23).

DISCUSSION

Sun exposure according to the questionnaire used was low, was associated with the presence of clinical activity and was weakly correlated with serum 25OHD concentration. More studies are needed to explore the use of individual questionnaires for sun exposure and its relationship with vitaminD in patients with IBD.

Factors affecting vitamin D deficiency in active inflammatory bowel diseases

BACKGROUND

Hypovitaminosis D is prevalent in inflammatory bowel disease (IBD) and may be associated with disease activity.

AIM

This study evaluated vitamin D (VitD) status in an Italian cohort of IBD patients, not taking VitD supplementation. We investigated risk factors for VitD deficiency and its correlation with disease activity.

METHODS

VitD levels were measured in 300 consecutive outpatients (42% with Crohn's Disease (CD) and 58% with ulcerative colitis (UC), 56% male) from a tertiary referral center. Data from the IBD cohort were compared with those of 234 healthy controls, matched by sex, age, and the month in which VitD levels were measured.

RESULTS

The mean VitD level in IBD patients was significantly lower than in controls (18.9 ng/ml vs. 25 ng/ml, p < 0.001) when accounting for gender, age, and season. VitD deficiency was present in 62% of IBD patients. Risk factors for deficiency were: age <40 and ≥60 years, winter, previous surgery, C-reactive protein (CRP) ≥0.5 mg/dl, and erythrocyte sedimentation rate ≥20 mm/h. In multivariate analysis, VitD levels were negatively influenced by disease location and CRP in UC.

CONCLUSIONS

Although VitD deficiency was more prevalent than expected in healthy controls living in a Mediterranean country not at high risk of hypovitaminosis D, it was more common and severe in IBD patients. This study also found an association between VitD status and disease activity.

Low Sun Exposure and Vitamin D Deficiency as Risk Factors for Inflammatory Bowel Disease, With a Focus on Childhood Onset

The incidence and prevalence of inflammatory bowel disease (IBD) are increasing worldwide. Some ecological studies show increasing incidence with increasing latitude. Ambient ultraviolet radiation varies inversely with latitude, and sun exposure of the skin is a major source of vitamin D. Vitamin D deficiency is common in patients with IBD. Sun exposure and vitamin D have immune effects that could plausibly reduce, or be protective for, IBD. One quarter of new IBD cases are diagnosed in childhood or adolescence, but most research is for adult-onset IBD. Here, we review the evidence for low sun exposure and/or vitamin D deficiency as risk factors for IBD, focusing where possible on pediatric IBD, where effects of environmental exposures may be clearer. The literature provides some evidence of a latitude gradient of IBD incidence, and evidence for seasonal patterns of timing of birth or disease onset is inconsistent. High prevalence of vitamin D deficiency occurs in people with IBD, but cannot be interpreted as being a causal risk factor. Evidence of vitamin D supplementation affecting disease activity is limited. Further research on predisease sun exposure and well-designed supplementation studies are required to elucidate whether these potentially modifiable exposures are indeed risk factors for IBD.