Association between early life exposure to agriculture, biodiversity, and green space and risk of inflammatory bowel disease: a population-based cohort study

Background

Specific pollutants and environmental exposures are implicated in modulating inflammatory bowel disease (IBD) risk. However, the role of environmental exposures, particularly during the early life period, towards IBD risk, has not been systematically evaluated.

Methods

We conducted a nationwide population-based cohort study during the study period extending from January 1, 1995, to September 1, 2020, using cross-linked Danish registers, maps, and inventories to ascertain the impact of agricultural land use, biodiversity, green space, urban space, blue space, and normalized difference vegetation index during pregnancy and the first two years of life on IBD, Crohn's disease (CD), and ulcerative colitis (UC) risk, using adjusted Cox proportional hazards regression analyses. We adjusted for covariates sex, maternal age at delivery, calendar year of birth, municipal-level socioeconomic status, and first-degree relative with IBD.

Findings

Of 1,438,487 individuals included in the study who were followed from age 2 years until a median (IQR) age of 14 (8-20) years, 3768 individuals were diagnosed with IBD. Exposure to the second, third and highest quartiles of agriculture land use during early life, relative to the lowest quartile, were associated with increased CD risk (aHR 1.12, 95% CI 1.01, 1.26, 1.19, 95% CI 1.05, 1.34 and, 1.24 95% CI 1.06, 1.46, respectively). There was no association of agriculture land use with UC risk. Conversely, exposure to the third quartile of biodiversity in early life, compared to the lowest quartile, were associated with a lower CD risk (aHR 0.86, 95% CI 0.75, 0.98). A protective effect of greenspace was noted in the highest quartile for CD (aHR 0.87, 95% CI 0.78, 0.98).

Interpretation

In a nationwide cohort with long-term follow up data, early life environmental exposures were associated with modulation of CD risk, with a harmful effect of agriculture land use and protective effect of biodiversity and green space.

Funding

Danish National Research Foundation, the International Organization for the Study of Inflammatory Bowel Disease, the National Institute of Diabetes and Digestive and Kidney Diseases.

Drug Repurposing in Crohn's Disease Using Danish Real-World Data

Aim

Drug repurposing, utilizing electronic healthcare records (EHRs), offers a promising alternative by repurposing existing drugs for new therapeutic indications, especially for patients lacking effective therapies. Intestinal fibrosis, a severe complication of Crohn's disease (CD), poses significant challenges, increasing morbidity and mortality without available pharmacological treatments. This article focuses on identifying medications associated with an elevated or reduced risk of fibrosis in CD patients through a population-wide real-world data and artificial intelligence (AI) approach.

Methods

Patients aged 65 or older with a diagnosis of CD from 1996 to 2019 in the Danish EHRs were followed for up to 24 years. The primary outcome was the need of specific surgical procedures, namely proctocolectomy with ileostomy and ileocecal resection as proxies of intestinal fibrosis. The study explored drugs linked to an increased or reduced risk of the study outcome through machine-learning driven survival analysis.

Results

Among the 9179 CD patients, 1029 (11.2%) underwent surgery, primarily men (58.5%), with a mean age of 76 years, 10 drugs were linked to an elevated risk of surgery for proctocolectomy with ileostomy and ileocecal resection. In contrast, 10 drugs were associated with a reduced risk of undergoing surgery for these conditions.

Conclusion

This study focuses on repurposing existing drugs to prevent surgery related to intestinal fibrosis in CD patients, using Danish EHRs and advanced statistical methods. The findings offer valuable insights into potential treatments for this condition, addressing a critical unmet medical need. Further research and clinical trials are warranted to validate the effectiveness of these repurposed drugs in preventing surgery related to intestinal fibrosis in CD patients.

Gut microbiota signatures in inflammatory bowel disease

BACKGROUND

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), affect millions of people worldwide with increasing incidence.

OBJECTIVES

Several studies have shown a link between gut microbiota composition and IBD, but results are often limited by small sample sizes. We aimed to re-analyze publicly available fecal microbiota data from IBD patients.

METHODS

We extracted original fecal 16S rRNA amplicon sequencing data from 45 cohorts of IBD patients and healthy individuals using the BioProject database at the National Center for Biotechnology Information. Unlike previous meta-analyses, we merged all study cohorts into a single dataset, including sex, age, geography, and disease information, based on which microbiota signatures were analyzed, while accounting for varying technical platforms.

RESULTS

Among 2518 individuals in the combined dataset, we discovered a hitherto unseen number of genera associated with IBD. A total of 77 genera associated with CD, of which 38 were novel associations, and a total of 64 genera associated with UC, of which 28 represented novel associations. Signatures were robust across different technical platforms and geographic locations. Reduced alpha diversity in IBD compared to healthy individuals, in CD compared to UC, and altered microbiota composition (beta diversity) in UC and especially in CD as compared to healthy individuals were found.

CONCLUSIONS

Combining original microbiota data from 45 cohorts, we identified a hitherto unseen large number of genera associated with IBD. Identification of microbiota features robustly associated with CD and UC may pave the way for the identification of new treatment targets.

Medication-Wide Study: Exploring Medication Use 10 Years Before a Diagnosis of Inflammatory Bowel Disease

INTRODUCTION

There is growing interest in the prediagnostic phase of inflammatory bowel disease (IBD) and in the overlap of IBD with other diseases. We described and compared use of any prescription medication between individuals with and without IBD in a 10-year period preceding diagnosis.

METHODS

Based on cross-linked nationwide registers, we identified 29,219 individuals diagnosed with IBD in Denmark between 2005 and 2018 and matched to 292,190 IBD-free individuals. The primary outcome was use of any prescription medication in years 1-10 before IBD diagnosis/matching date. Participants were considered as medication users if they redeemed ≥1 prescription for any medication in the World Health Organization Anatomical Therapeutic Chemical (ATC) main groups or subgroups before diagnosis/matching.

RESULTS

The IBD population had a universally increased use of medications compared with the matched population before IBD diagnosis. At 10 years before diagnosis, the proportion of users was 1.1-fold to 1.8-fold higher in the IBD population in 12 of 14 ATC main groups of medication ( P -value < 0.0001). This applied across age, sex, and IBD subtypes, although it was the most pronounced for Crohn's disease (CD). Two years before diagnosis, the IBD population had a steep increase in medication use for several organ systems. When analyzing therapeutic subgroups of medication, the CD population exhibited 2.7, 2.3, 1.9, and 1.9 times more users of immunosuppressants, antianemic preparations, analgesics, and psycholeptics, respectively, than the matched population 10 years before diagnosis ( P -value < 0.0001).

DISCUSSION

Our findings demonstrate universally increased medication use years before IBD, especially CD, diagnosis and indicates multiorgan involvement in IBD.

Characterizing the pre-clinical phase of inflammatory bowel disease

Understanding the biological changes that precede a diagnosis of inflammatory bowel disease (IBD) could facilitate pre-emptive interventions, including risk factor modification, but this pre-clinical phase of disease remains poorly characterized. Using measurements from 17 hematological and biochemical parameters taken up to 10 years before diagnosis in over 20,000 IBD patients and population controls, we address this at massive scale. We observe widespread significant changes in multiple biochemical and hematological parameters that occur up to 8 years before diagnosis of Crohn's disease (CD) and up to 3 years before diagnosis of ulcerative colitis. These changes far exceed previous expectations regarding the length of this pre-diagnostic phase, revealing an opportunity for earlier intervention, especially in CD. In summary, using a nationwide, case-control dataset-obtained from the Danish registers-we provide a comprehensive characterization of the hematological and biochemical changes that occur in the pre-clinical phase of IBD.

Early Ileocecal Resection for Crohn's Disease Is Associated With Improved Long-term Outcomes Compared With Anti-Tumor Necrosis Factor Therapy: A Population-Based Cohort Study

BACKGROUND & AIMS

Early Crohn's disease (CD) treatment involves anti-tumor necrosis factor (TNF) agents, whereas ileocecal resection (ICR) is reserved for complicated CD or treatment failure. We compared long-term outcomes of primary ICR and anti-TNF therapy for ileocecal CD.

METHODS

Using cross-linked nationwide registers, we identified all individuals diagnosed with ileal or ileocecal CD between 2003 and 2018 and treated with ICR or anti-TNF agents within 1 year of diagnosis. The primary outcome was a composite of ≥1 of the following: CD-related hospitalization, systemic corticosteroid exposure, CD-related surgery, and perianal CD. We conducted adjusted Cox's proportional hazards regression analyses and determined the cumulative risk of different treatments after primary ICR or anti-TNF therapy.

RESULTS

Of 16,443 individuals diagnosed with CD, 1279 individuals fulfilled the inclusion criteria. Of these, 45.4% underwent ICR and 54.6% received anti-TNF. The composite outcome occurred in 273 individuals (incidence rate, 110/1000 person-years) in the ICR group and in 318 individuals (incidence rate, 202/1000 person-years) in the anti-TNF group. The risk of the composite outcome was 33% lower with ICR compared with anti-TNF (adjusted hazard ratio, 0.67; 95% confidence interval, 0.54-0.83). ICR was associated with reduced risk of systemic corticosteroid exposure and CD-related surgery, but not other secondary outcomes. The proportion of individuals on immunomodulator, anti-TNF, who underwent subsequent resection, or were on no therapy 5 years post-ICR was 46.3%, 16.8%, 1.8%, and 49.7%, respectively.

CONCLUSION

These data suggest that ICR may have a role as first-line therapy in CD management and challenge the current paradigm of reserving surgery for complicated CD refractory or intolerant to medications. Yet, given inherent biases associated with observational data, our findings should be interpreted and applied cautiously in clinical decision making.

The appendix and ulcerative colitis - an unsolved connection

The appendix is thought to have a role in the pathogenesis of ulcerative colitis, but the nature and basis of this association remains unclear. In this Perspective, we consider the biology of the appendix with respect to its immunological function and the microbiome, and how this relates to evidence that supports the involvement of the appendix in ulcerative colitis. In experimental models, removal of the inflamed appendix prevents colitis, and in human observational studies, appendectomy is associated with protection against ulcerative colitis. Further, among people who develop ulcerative colitis, appendectomy before diagnosis might influence the course and outcomes of the disease - some evidence suggests that it protects against colectomy but could increase the risk of colorectal cancer. Appendectomy after onset of ulcerative colitis seems to have disparate consequences. Clinical trials to understand whether appendectomy has a role in the treatment of ulcerative colitis are ongoing. Major questions about the role of the appendix in the pathogenesis of ulcerative colitis remain unanswered, and further research is needed to establish whether the connection is clinically relevant.

Genetic analysis of blood molecular phenotypes reveals common properties in the regulatory networks affecting complex traits

We evaluate the shared genetic regulation of mRNA molecules, proteins and metabolites derived from whole blood from 3029 human donors. We find abundant allelic heterogeneity, where multiple variants regulate a particular molecular phenotype, and pleiotropy, where a single variant associates with multiple molecular phenotypes over multiple genomic regions. The highest proportion of share genetic regulation is detected between gene expression and proteins (66.6%), with a further median shared genetic associations across 49 different tissues of 78.3% and 62.4% between plasma proteins and gene expression. We represent the genetic and molecular associations in networks including 2828 known GWAS variants, showing that GWAS variants are more often connected to gene expression in trans than other molecular phenotypes in the network. Our work provides a roadmap to understanding molecular networks and deriving the underlying mechanism of action of GWAS variants using different molecular phenotypes in an accessible tissue.

The bidirectional risk of inflammatory bowel disease and anxiety or depression: A systematic review and meta-analysis

OBJECTIVE

Inflammatory bowel disease (IBD) is associated with anxiety and depression, but the magnitude and directionality of risk remains uncertain. This study quantifies the risk of anxiety or depression following a diagnosis of IBD, and the risk of IBD in individuals with anxiety or depression, using population representative data.

METHOD

We performed a systematic literature search using MEDLINE and Embase and included unselected cohort studies reporting risk of anxiety or depression in patients with IBD or risk of IBD in patients with anxiety or depression. We undertook Random Effect Model meta-analysis to calculate pooled Hazard Ratios (HR) for the risk of anxiety and depression in IBD and subgroup meta-analysis to calculate risk by IBD subtype and in pediatric-onset IBD.

RESULTS

Nine studies were included; seven of which examined incidence of anxiety or depression among a total of >150,000 IBD patients. Meta-analysis showed an increased risk of both anxiety (HR: 1.48, 95% CI: 1.29-1.70) and depression (HR: 1.55, 95% CI: 1.35-1.78) following IBD diagnosis. Two studies investigating >400,000 individuals with depression showed a 2-fold increased risk of IBD.

CONCLUSIONS

The bidirectional association between IBD and anxiety and depression is clinically relevant and could indicate shared or mutually dependent disease mechanisms.

Longitudinal trajectories of anxiety, depression, and bipolar disorder in inflammatory bowel disease: a population-based cohort study

Background

Inflammatory bowel disease (IBD) is associated with psychiatric diseases, but it is unclear to what degree patients with IBD are affected over their lifetime. We aimed to longitudinally investigate the risk of anxiety, depression, and bipolar disorder before and after IBD diagnosis to understand the full burden of these diseases in patients with IBD.

Methods

In this population based cohort study, we identified 22,103 patients diagnosed with IBD between January 1, 2003 and December 31, 2013 in the Danish National registers and 110,515 matched reference individuals from the general population. We calculated yearly prevalence of hospital contacts for anxiety, depression, and bipolar disorder and dispensed prescriptions for antidepressants from five years before to ten years after IBD diagnosis. We used logistic regression to calculate prevalence odds ratios (OR) for each outcome prior to IBD diagnosis, and Cox regression to calculate hazard ratios (HR) of new outcomes after IBD diagnosis.

Findings

During >150,000 person years follow-up, patients with IBD had higher risk of anxiety (OR 1.4; 95% confidence interval (CI) 1.2-1.7) and depression (OR 1.4; 95% CI 1.3-1.6) starting at least five years before and continuing until at least ten years after IBD diagnosis (HR 1.3; 95% CI 1.1-1.5 for anxiety and HR 1.5; 95% CI 1.4-1.7 for depression). The risk was particularly high around IBD diagnosis and in patients diagnosed with IBD after the age of 40 years. We found no association between IBD and bipolar disorder.

Interpretation

This population-based study suggests that anxiety and depression are clinically significant comorbidities of IBD both before and after IBD diagnosis, which warrant thorough evaluation and management, particularly around the time of IBD diagnosis.

Funding

The Danish National Research Foundation [DNRF148], the Lundbeck Foundation [R313-2019-857], and Aage og Johanne Louis-Hansens Fond [9688-3374 TJS].

Non-culture-based studies of the appendiceal microbiota: a systematic review

Aims: To review studies examining the appendiceal microbiota and microbial changes in acute appendicitis. Methods: After a systematic literature search, 11 studies examining the appendiceal microbiota (414 samples) using non-culture-based methods were included. Results: The appendiceal microbiota showed decreased α-diversity compared with fecal microbiota. Inflamed and uninflamed appendices showed differences in β-diversity, and there was an increased abundance of oral-associated bacteria in inflamed versus uninflamed appendices. Conclusion: The appendiceal microbiota exhibits lower α-diversity than the fecal microbiota, with an increased abundance of oral-associated bacteria. Compared with uninflamed appendices, the appendix microbiota in acute appendicitis also showed increased abundance of oral-associated bacteria, but no bacterial profile unique to either complicated or uncomplicated appendicitis was found.

Risk Factors for Developing Inflammatory Bowel Disease Within and Across Families with a Family History of IBD

INTRODUCTION

A family history of inflammatory bowel disease [IBD] is the strongest risk factor for disease. However, some first-degree relatives (FDRs) will develop disease, while others will not.

METHODS

Using the nationwide Danish National Patient Register, we examined risk factors in families with two or more affected FDRs. First, we compared exposures between siblings with and without IBD within the same family [within-family analysis]. Second, we compared exposures between individuals with and without IBD across all families [across-family analysis]. Exposures included sex, birth order, mode of delivery, antibiotics, personal and family history of immune-mediated diseases, gastrointestinal infections, and surgical history preceding diagnosis. Uni- and multivariable conditional logistic regression analyses were conducted.

RESULTS

In the 'within-family analysis', 1669 families were included [1732 cases, 2447 controls]. Female sex (adjusted odds ratio [aOR]: 1.40, 95% confidence interval [CI] 1.23, 1.59), history of ankylosing spondylitis [aOR: 2.88, 95% CI 1.05, 7.91] and exposure to antibiotics [aOR: 1.28, 95% CI 1.02, 1.61] increased the risk for IBD. In the 'across-family analysis', 1254 cases and 37 584 controls were included, confirming an association with prior ankylosing spondylitis [aOR: 3.92, 95% CI 1.38, 11.12] and exposure to antibiotics [aOR: 1.29, 95% CI 1.04, 1.60]. Having two or more relatives [aOR: 6.26, 95% CI 1.34, 29.29] or a sibling with IBD [aOR: 1.36, 95% CI 1.18, 1.57] increased the risk of IBD. Appendectomy reduced the risk of ulcerative colitis [aOR: 0.32, 95% CI 0.14, 0.72].

CONCLUSION

In families with IBD, we identified risk factors for the unaffected FDR to develop disease. These findings provide an opportunity for counselling IBD relatives.

Increasing Incidence of Pouchitis Between 1996 and 2018: A Population-Based Danish Cohort Study

BACKGROUND & AIMS

Current knowledge regarding the epidemiology of pouchitis is based on highly selected, mostly single-center, patient cohorts. Our objective was to prospectively determine the population-based incidence of pouchitis in patients with ulcerative colitis in the first 2 years after ileal pouch-anal anastomosis and analyze time trends of the incidence of pouchitis.

METHODS

Using national registries, we established a population-based cohort of all Danish patients undergoing proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis between 1996 and 2018. The primary outcome was the development of pouchitis within the first 2 years after surgery, evaluated by time period. We used Kaplan-Meier and Cox proportional hazard modeling to evaluate the time to development of pouchitis.

RESULTS

Overall, 1664 patients underwent an ileal pouch-anal anastomosis. The cumulative incidence of pouchitis in the 2 years after ileal pouch-anal anastomosis increased throughout the study period, from 40% in the period from 1996 to 2000 (95% CI, 35%-46%) to 55% in the period from 2015 to 2018 (95% CI, 48%-63%). Patients undergoing surgery between 2015 and 2018 also showed an increased risk of pouchitis compared with the earliest study period (1996-2000) after adjusting for sex, age, and socioeconomic status (hazard ratio, 1.57; 95% CI, 1.20-2.05).

CONCLUSIONS

This population-based study showed a 15% absolute and 38% relative increase in the incidence of pouchitis among patients undergoing surgery between 1996 and 2018, with the greatest cumulative incidence of pouchitis shown in the most recent era (2015-2018). The striking increase in the incidence of pouchitis highlights the need for further research into causes and prevention of pouchitis.

The Rising Burden of Inflammatory Bowel Disease in Denmark Over Two Decades: A Nationwide Cohort Study

BACKGROUND & AIMS

Shifts in epidemiological stages of inflammatory bowel disease (IBD) carry implications toward understanding IBD etiology and managing clinical care. We conducted a temporal analysis of the epidemiology of IBD between 1995 and 2016 in the Danish nationwide cohort.

METHODS

We used the Danish registers to obtain data on demographics and IBD-related outpatient and inpatient contacts between 1995 and 2016. IBD diagnosis was defined as having ≥2 registrations related to Crohn's disease (CD) or ulcerative colitis (UC) within a 2-year period. We estimated overall and annual incidence rates and prevalence of CD and UC standardized with respect to age and sex.

RESULTS

A total of 47,830 individuals met the criteria for IBD diagnosis, of which 33% were diagnosed with CD and 67% with UC. Between 1995 and 2016, the incidence rate (95% confidence interval) per 100,000 person-years rose from 9.1 (8.3-10.0) to 17.8 (16.8-19.0) for CD, and from 21.0 (19.8-22.3) to 28.4 (27.0-29.8) for UC. The highest increase in CD and UC incidence rates occurred in children and young adults, respectively. The prevalence of IBD doubled from 1995 to 2016; the greatest increase (2.5-fold) was in UC prevalence among individuals aged >40 years. During this period, the median age of the IBD population increased by 6 to 7 years.

CONCLUSIONS

In Denmark, the incidence and prevalence of IBD have increased during the last 2 decades. The IBD population is shifting toward an older age. These findings have implications towards understanding environmental shifts as well as preparing health care systems for an aging IBD population.

Early-Life Mebendazole Exposure Increases the Risk of Adult-Onset Ulcerative Colitis: A Population-Based Cohort Study

INTRODUCTION

According to the hygiene hypothesis, exposure to parasites may protect against inflammatory bowel disease (IBD). Our aim was to examine the risk of IBD with childhood exposure to mebendazole, a broad-spectrum antihelminthic agent.

METHODS

We conducted a population-based cohort study using prospectively collected historical data of all individuals born in Denmark between 1995 and 2018. We identified mebendazole exposure at age younger than 18 years and during early life (younger than 5 years). We performed adjusted Cox proportional hazards regression analysis to determine the risk of IBD, ulcerative colitis (UC), and Crohn's disease with mebendazole exposure after adjusting for potential confounders.

RESULTS

Of 1,520,290 individuals in the cohort, 615,794 had childhood or adolescence mebendazole exposure. One thousand five hundred fifty-five and 1,499 individuals were subsequently diagnosed with pediatric-onset and adult-onset IBD, respectively. On multivariable analysis, mebendazole exposure at age younger than 18 years did not affect pediatric-onset or adult-onset IBD risk (adjusted hazard ratio [aHR] 0.97, 95% confidence interval [CI] 0.87, 1.07, and 1.08, 95% CI 0.97, 1.19, respectively). On limiting mebendazole exposure to age younger than 5 years while there was no association with pediatric-onset IBD (aHR 0.98, 95% CI 0.87, 1.11), adult-onset IBD risk was increased (aHR 1.17, 95% CI 1.04, 1.31). This increase in risk was driven by UC (aHR 1.32, 95% CI 1.12, 1.55), but not Crohn's disease (1.03, 95% CI 0.87, 1.22).

DISCUSSION

Early-life mebendazole exposure is associated with an increase in the risk of adult-onset UC. These findings suggest the importance of early-life exposures in shaping the risk of IBD later in life.

Depression and anxiety in inflammatory bowel disease: epidemiology, mechanisms and treatment

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, is a chronic, relapsing immune-mediated disease with a varying and sometimes severe disease course. IBD is often diagnosed in early adulthood and can lead to a substantial decline in quality of life. It has been suggested that patients with IBD are at increased risk of depression and anxiety, but it is still unclear to what extent these diseases co-occur and in what sequence they arise. This Review summarizes the literature on the degree of co-occurrence of IBD with depression and anxiety and the temporal relationship between these diseases. We also discuss the effect of psychological stress on the onset and course of IBD. In addition, we outline the possible mechanisms underlying the co-occurrence of IBD and depression and anxiety, which include changes in brain signalling and morphology, increases in peripheral and intracerebral pro-inflammatory cytokines, impairment of the nitric oxide pathway, changes in vagal nerve signalling, gut dysbiosis and genetics. Finally, we examine the possible effects of treatment of depression and anxiety on the risk and course of IBD, the influence of psychological interventions on IBD, and the effects of IBD treatment on psychiatric comorbidity.

Body mass index trajectories in childhood and incidence rates of type 2 diabetes and coronary heart disease in adulthood: A cohort study

AIMS

We examined associations between five body mass index (BMI) trajectories from ages 6-15 years and register-based adult-onset type 2 diabetes mellitus (T2D) and coronary heart disease (CHD) with and without adjustment for adult BMI.

METHODS

Child and adult BMI came from two Danish cohorts and 13,205 and 13,438 individuals were included in T2D and CHD analyses, respectively. Trajectories were estimated by latent class modelling. Incidence rate ratios (IRRs) were estimated with Poisson regression.

RESULTS

In models without adult BMI, compared to the lowest trajectory, among men the T2D IRRs were 0.92 (95 %CI:0.77-1.09) for the second lowest trajectory and 1.51 (95 %CI:0.71-3.20) for the highest trajectory. The corresponding IRRs in women were 0.92 (95 %CI:0.74-1.16) and 3.58 (95 %CI:2.30-5.57). In models including adult BMI, compared to the lowest trajectory, T2D IRRs in men were 0.57 (95 %CI:0.47-0.68) for the second lowest trajectory and 0.26 (95 %CI:0.12-0.56) for the highest trajectory. The corresponding IRRs in women were 0.60 (95 %CI:0.48-0.75) and 0.59 (95 %CI:0.36-0.96). The associations were similar in direction, but not statistically significant, for CHD.

CONCLUSIONS

Incidence rates of adult-onset T2D were greater for a high child BMI trajectory than a low child BMI trajectory, but not in models that included adult BMI.

Comparative Outcomes and Safety of Vedolizumab vs Tumor Necrosis Factor Antagonists for Older Adults With Inflammatory Bowel Diseases

IMPORTANCE

Observational comparative effectiveness studies can inform the positioning of biologic therapies for older patients with inflammatory bowel disease (IBD) who are underrepresented in clinical trials.

OBJECTIVE

To compare the effectiveness and safety of vedolizumab vs tumor necrosis factor (TNF) for older patients with IBD.

DESIGN, SETTING, AND PARTICIPANTS

This active comparator, new-user design, comparative effectiveness study was conducted between January 1, 2005, and December 31, 2018, among 754 older patients (aged ≥50 years) with IBD from the Danish National Patient Register. The mean follow-up after treatment initiation took place at 32 to 40 weeks. Statistical analysis was performed from February 1 to April 27, 2022.

INTERVENTIONS

Treatment with vedolizumab or TNF antagonists.

MAIN OUTCOMES AND MEASURES

The primary effectiveness outcome was treatment failure, defined as the composite risk of IBD-related hospitalization, IBD-related surgery, or a new corticosteroid prescription more than 6 weeks after initiation of treatment with biologic therapy. Secondary effectiveness outcomes were time to each individual component of the composite effectiveness outcome. The primary safety outcome was the risk of serious infections, defined as infections requiring hospitalization. A 1:1 propensity score-matched analysis was conducted, accounting for patient-, disease-, and treatment-associated factors.

RESULTS

The study compared 377 older patients with IBD with incident use of vedolizumab (202 women [53.6%]; mean [SD] age, 61.2 [8.3] years; 177 [46.9%] with Crohn disease) vs 377 patients with incident use of TNF antagonists (206 women [54.6%]; mean [SD] age, 61.3 [8.1] years; 182 [48.3%] with Crohn disease). Overall, vedolizumab was associated with an increased risk of treatment failure compared with TNF antagonists (1-year risk, 45.4% vs 34.7%; adjusted hazard ratio [HR], 1.31; 95% CI, 1.02-1.69), including higher risk of IBD-related hospitalization (1-year risk, 27.8% vs 16.3%; adjusted HR, 1.48; 95% CI, 1.03-2.15) and IBD-related major abdominal surgery (1-year risk, 21.3% vs 8.0%; adjusted HR, 2.39; 95% CI, 1.45-3.94). In subgroup analysis by IBD phenotype, among patients with Crohn disease, vedolizumab was associated with a 77% higher risk of treatment failure (adjusted HR, 1.77; 95% CI, 1.21-2.58), while no difference in risk of treatment failure was seen among patients with ulcerative colitis (adjusted HR, 1.04; 95% CI, 0.75-1.43; P = .03 for interaction). There was no significant difference in the risk of serious infections, overall (1-year risk, 8.2% vs 8.7%; adjusted HR, 1.04; 95% CI, 0.58-1.85) and by IBD phenotype.

CONCLUSIONS AND RELEVANCE

In this comparative effectiveness study of older patients with IBD, vedolizumab was associated with a higher risk of treatment failure compared with TNF antagonists, particularly among patients with Crohn disease, without offering a significant safety advantage.

Impact of thiopurine discontinuation at anti-tumour necrosis factor initiation in inflammatory bowel disease treatment: a nationwide Danish cohort study

BACKGROUND

Escalation to anti-tumour necrosis factor (anti-TNF) in inflammatory bowel disease (IBD) patients on thiopurine is a common clinical scenario. However, the impact of discontinuing thiopurine at escalation is unclear.

AIM

To assess the impact of discontinuing versus continuing thiopurine therapy at anti-TNF initiation.

METHODS

We used the Danish registries to establish a national cohort of patients with IBD on thiopurine therapy prior to initiating anti-TNF from 2003 to 2018. We compared patients discontinuing thiopurine therapy within 90 days of anti-TNF initiation to those continuing. Our primary outcome was a composite of any new oral corticosteroid use, IBD-related hospitalization, surgery or death. We used Cox regression models to calculate adjusted hazard ratios (aHR) and 95% confidence intervals (CI).

RESULTS

Of the 10,352 anti-TNF exposed patients, 2,630 (1590 Crohn's disease (CD) and 1040 ulcerative colitis (UC)) received thiopurines prior to anti-TNF. After anti-TNF initiation, 979 patients discontinued thiopurines. Discontinuing thiopurines within 90 days of anti-TNF initiation, increased the risk of the primary outcome (aHR: 1.22; 95% CI: 1.10-1.36), particularly for IBD-related hospitalization (aHR: 1.14; 95% CI: 1.00-1.31) and oral corticosteroid use (aHR: 1.27; 95% CI: 1.13-1.44). This increased risk of the primary outcome was seen in both CD (aHR: 1.17; 95% CI 1.02-1.34) and UC (aHR: 1.32; 95% CI: 1.12-1.55).

CONCLUSIONS

In a nationwide cohort study of IBD patients, we observed that discontinuing thiopurines after anti-TNF initiation was associated with an increased risk of adverse outcomes, in particular an increase in hospitalizations. Further interventional studies exploring this common clinical scenario are required.

Increased risk of genital warts in inflammatory bowel disease: A Danish registry-based cohort study (1996-2018)

Background

Patients with inflammatory bowel disease (IBD) are at increased risk of human papillomavirus (HPV) related cancers such as anal squamous cell carcinoma. However, risk of non‐malignant HPV infection has never been systematically studied in IBD. This study aims to assess the risk of genital warts (GW) in IBD patients.

Methods

Using the Danish nationwide registries, we identified 49,163 patients with IBD between 1996 and 2018 and matched them to 491,665 individuals from the general population by age, sex, and HPV immunisation. Cumulative incidence rates for GW in IBD and non‐IBD patients were calculated by age. Cox proportional regression analysis was used to calculate hazard ratios (HR) for GW in IBD compared to matched population and in Crohn's disease (CD) compared to ulcerative colitis (UC). We undertook subgroup analysis for risk of GW by sex, year of IBD diagnosis, contraceptive exposure and IBD treatment exposure.

Results

The fully adjusted HR for GW in IBD patients compared to the matched non‐IBD population was 1.33 (95% CI: 1.19–1.49) and 1.13 (95% CI: 1.01, 1.27) in CD as compared to UC. This increased risk was particularly observed in female (HR: 1.54, 95% CI: 1.33–1.79) over male (HR: 1.14, 95% CI: 0.97–1.34) IBD patients, but was also found across all periods of diagnosis with IBD, regardless of contraceptive treatment exposure, and also seen in IBD patients who had never been exposed to immunosuppressive treatment (HR: 1.33, 95% CI: 1.19–1.49).

Conclusion

In this nationwide, population‐representative cohort study, we observed a 33% increased risk of GW in patients with IBD compared to the matched population and a 13% increased risk of GW in CD compared with UC. This risk was particularly increased in female over male IBD patients and seen independent of IBD treatment exposure.

Development of Cancer Among Patients With Pediatric-Onset Inflammatory Bowel Disease: A Meta-analysis of Population-Based Studies

IMPORTANCE

Because the incidence of pediatric-onset inflammatory bowel disease (IBD) is increasing, knowledge of the long-term risk of cancer in this patient population is required.

OBJECTIVE

To evaluate the relative rate of cancer among patients with pediatric-onset IBD.

DATA SOURCES

A comprehensive systematic search was performed of MEDLINE and Embase from the date of database inception to October 31, 2021.

STUDY SELECTION

All unselected, population-based cohort studies of pediatric-onset IBD assessing the risk of cancer were included. Tertiary center referrals and insurance database studies were excluded. All articles were assessed by 2 independent reviewers.

DATA EXTRACTION AND SYNTHESIS

The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline for data extraction and used the Newcastle-Ottawa Scale for assessment of the risk of bias and the quality of included articles.

MAIN OUTCOMES AND MEASURES

A random-effects model meta-analysis was conducted of included studies using the inverse-variance method to assess the relative rate of cancer overall and by IBD subtype (Crohn disease or ulcerative colitis), sex, and thiopurine exposure among patients with pediatric-onset IBD. Pooled relative rates (pRRs) along with 95% CIs were calculated for combined studies.

RESULTS

Of 4628 articles screened, 5 population-based studies from North America and Europe were eligible for inclusion. These studies comprised 19 812 individuals with pediatric-onset IBD followed up for 283 540 person-years in which 715 cases of cancer were identified. Meta-analysis of pRR estimates showed a 2.4-fold increased rate of cancer among patients with pediatric-onset IBD (pRR, 2.46; 95% CI, 2.06-2.93), seen among patients with Crohn disease (pRR, 2.03; 95% CI, 1.67-2.46) and those with ulcerative colitis (pRR, 2.61; 95% CI, 2.00-3.40). This increased rate is primarily due to an increased rate of liver (pRR, 55.45; 95% CI, 19.59-156.99), colorectal (pRR, 20.29; 95% CI, 15.90-25.90), and small bowel (pRR, 16.20; 95% CI, 3.52-74.66) cancers. The incidence rate of cancer among patients with pediatric-onset IBD was reported by 4 studies and ranged from 1.0 to 3.3 cases per 1000 person-years.

CONCLUSIONS AND RELEVANCE

This meta-analysis of unselected, population-based studies showed a greater than 2-fold increased rate of cancer among patients with pediatric-onset IBD compared with the general pediatric populations, primarily owing to an increased rate of gastrointestinal cancers.

Development of Inflammatory Bowel Disease in HIV Patients: A Danish Cohort Study (1983–2018) With American Validation (1999–2018)

BACKGROUND AND AIMS

Human immunodeficiency virus (HIV) infection is associated with several immune-mediated disorders. However, the risk of inflammatory bowel disease (IBD) in people living with HIV (PLWH) remains unclear. We aimed to assess the risk of IBD among PLWH using a nationwide, population-based Danish cohort and to validate findings in a large American insurance-based database.

METHODS

Using Danish registries (1983-2018), we identified 8995 PLWH and age- and sex-matched them to 449,750 HIV-negative individuals. Cox regression analysis was undertaken to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for IBD diagnosis. Results were stratified by sex, age, and year of HIV diagnosis. Using an American insurance-based cohort, Explorys (1999-2018), we assessed the prevalence odds ratio (OR) and 95% CI of IBD diagnosis in PLWH compared with HIV-negative individuals.

RESULTS

IBD diagnosis among PLWH in Denmark was increased (HR: 2.25, 95% CI: 1.78-2.83) compared with matched HIV-negative individuals. This was seen for both Crohn's disease (HR: 2.25, 95% CI: 1.47-3.44) and ulcerative colitis (HR: 2.24, 95% CI: 1.70-2.96) and in male (HR: 2.75, 95% CI: 2.15-3.52) but not female (HR: 0.93, 95% CI: 0.48-1.79) PLWH. Explorys analysis also showed an increased odds of IBD diagnoses among PLWH (OR: 1.41; 95% CI: 1.35-1.49).

CONCLUSION

This study finds an increased risk of IBD diagnosis among PLWH in both a Danish and US cohort, highlighting a need to consider IBD in PLWH with new-onset gastrointestinal symptoms. Further research into the role of antiretroviral therapy in this relationship is required.

The Risk of Type 2 Diabetes in Patients With Inflammatory Bowel Disease After Bowel Resections: A Nationwide Cohort Study

BACKGROUND AND AIMS:

Patients with inflammatory bowel disease (IBD) are at increased risk of type 2 diabetes (T2D), but the underlying mechanisms remain elusive. We aimed to determine the impact of small and large bowel resections on the risk of developing T2D in patients with IBD.

METHODS:

We conducted a nationwide, prospective study of all IBD patients undergoing small bowel resection (Crohn’s disease [CD]) and large bowel resection (CD and ulcerative colitis [UC]) in Denmark (1996–2018). Each patient was matched with up to 5 patients with IBD and no history of bowel resection. We used Cox proportional hazards regression models to estimate adjusted hazard ratios (aHRs) of T2D.

RESULTS:

We included 2469 patients with CD and small bowel resection, 1361 patients with CD and large bowel resection, and 3787 patients with UC and large bowel resection. Small bowel resection in CD patients was associated with lower risk of T2D (aHR 0.65, 95% CI, 0.44–0.92), compared with matched patients with CD and no bowel resection. Large bowel resection in patients with CD or UC was associated with aHRs of 0.95 (95% CI, 0.67–1.31) and 1.25 (95% CI, 1.03–1.51), respectively, compared with matched patients with CD or UC and no bowel resection.

CONCLUSION:

Patients with CD and small bowel resection have a lower risk of T2D, whereas patients with UC and large bowel resection have a higher risk of T2D, compared with patients with IBD and no bowel resection history. The underlying mechanisms remain to be explored.

Profiles of Glucose Metabolism in Different Prediabetes Phenotypes, Classified by Fasting Glycemia, 2-Hour OGTT, Glycated Hemoglobin, and 1-Hour OGTT: An IMI DIRECT Study

Differences in glucose metabolism among categories of prediabetes have not been systematically investigated. In this longitudinal study, participants (N = 2,111) underwent a 2-h 75-g oral glucose tolerance test (OGTT) at baseline and 48 months. HbA_1c was also measured. We classified participants as having isolated prediabetes defect (impaired fasting glucose [IFG], impaired glucose tolerance [IGT], or HbA_1c indicative of prediabetes [IA1c]), two defects (IFG+IGT, IFG+IA1c, or IGT+IA1c), or all defects (IFG+IGT+IA1c). β-Cell function (BCF) and insulin sensitivity were assessed from OGTT. At baseline, in pooling of participants with isolated defects, they showed impairment in both BCF and insulin sensitivity compared with healthy control subjects. Pooled groups with two or three defects showed progressive further deterioration. Among groups with isolated defect, those with IGT showed lower insulin sensitivity, insulin secretion at reference glucose (ISR_r), and insulin secretion potentiation (P < 0.002). Conversely, those with IA1c showed higher insulin sensitivity and ISR_r (P < 0.0001). Among groups with two defects, we similarly found differences in both BCF and insulin sensitivity. At 48 months, we found higher type 2 diabetes incidence for progressively increasing number of prediabetes defects (odds ratio >2, P < 0.008). In conclusion, the prediabetes groups showed differences in type/degree of glucometabolic impairment. Compared with the pooled group with isolated defects, those with double or triple defect showed progressive differences in diabetes incidence.

Airway hyperresponsiveness to inhaled mannitol identifies a cluster of non-eosinophilic asthma patients with high symptom burden

BACKGROUND

Patients with asthma are heterogeneous in clinical presentation and in response to treatment. Despite this, tools to guide treatment are limited and include mainly measures of eosinophilic inflammation and symptoms. Airway hyperresponsiveness (AHR) to mannitol is present in patients across inflammatory phenotypes and improve with inhaled cortico-steroids.

OBJECTIVE

To investigate whether measuring AHR to mannitol in addition to eosinophilic inflammation and symptoms add information to the phenotypic characterization of patients with asthma.

METHODS

A total of 317 patients with asthma from six different cohorts were included in the analysis. All patients had measures of AHR to mannitol, blood eosinophils and ACQ-5 available. A cluster analysis using Wards minimum variance method was performed. The distribution of FeNO, IgE, lung function, induced sputum inflammatory cell count, age of onset and severity of disease was compared between clusters.

RESULTS

Four clusters were identified. Three of the clusters had proportionate levels of AHR, eosinophilic inflammation and symptoms, but one cluster presented with low levels of eosinophilic inflammation and a significant symptom burden. Half of the subjects in this cluster presented with AHR to inhaled mannitol. Lung function, fractional exhaled nitric oxide, Body Mass Index and IgE were normal.

CONCLUSION

Information on AHR to mannitol in addition to blood eosinophils and symptoms identifies a subgroup of asthma patients with symptomatic, non-eosinophilic disease. AHR to mannitol may provide a treatable trait in a subgroup of patients with non-eosinophilic asthma.

Bariatric Surgery and Risk of New-onset Inflammatory Bowel Disease: A Nationwide Cohort Study

BACKGROUND AND AIMS

The aim of this study was to examine the risk of new-onset inflammatory bowel disease [IBD] following bariatric surgery.

METHODS

We conducted a nationwide population-based prospective cohort study of the entire Danish population 18 to 60 years of age, alive, and residing in Denmark, from 1996 to 2018. Bariatric surgery was included as a time-dependent variable, and Cox proportional hazards regression models were used to estimate hazard ratios [HRs] of IBD. We used a model adjusting for age, sex, and birth cohort and a multifactor-adjusted model additionally including educational status and number of obesity-related comorbidities.

RESULTS

We followed 3 917 843 individuals of whom 15 347 had a bariatric surgery, for development of new-onset IBD. During 106 420 person-years following bariatric surgery, 100 IBD events occurred [incidence rate 0.940/1000 person-years]. During 55 553 785 person-years without bariatric surgery, 35 294 events of IBD occurred [incidence rate 0.635/1000 person-years]. This corresponded to a multifactor-adjusted hazard ratio [HR] of 1.15 (95% confidence interval[CI], 0.94-1.40) for IBD. Multifactor-adjusted HRs of Crohn's disease [CD] and ulcerative colitis [UC] were 1.85 [95% CI, 1.40-2.44] and 0.81 [95% CI, 0.61-1.08], respectively. Among women, the multifactor-adjusted HR for CD was 2.18 [95% CI, 1.64-2.90]. When limiting the study population to individuals with a diagnosis of overweight/obesity, bariatric surgery remained associated with increased risk of CD, multifactor-adjusted HR 1.59 [95% CI, 1.18-2.13].

CONCLUSIONS

This nationwide cohort study shows that bariatric surgery is associated with increased risk of development of new-onset CD, but not of UC. The underlying mechanisms remain elusive.

Processes Underlying Glycemic Deterioration in Type 2 Diabetes: An IMI DIRECT Study

OBJECTIVE

We investigated the processes underlying glycemic deterioration in type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

A total of 732 recently diagnosed patients with T2D from the Innovative Medicines Initiative Diabetes Research on Patient Stratification (IMI DIRECT) study were extensively phenotyped over 3 years, including measures of insulin sensitivity (OGIS), β-cell glucose sensitivity (GS), and insulin clearance (CLIm) from mixed meal tests, liver enzymes, lipid profiles, and baseline regional fat from MRI. The associations between the longitudinal metabolic patterns and HbA_1c deterioration, adjusted for changes in BMI and in diabetes medications, were assessed via stepwise multivariable linear and logistic regression.

RESULTS

Faster HbA_1c progression was independently associated with faster deterioration of OGIS and GS and increasing CLIm; visceral or liver fat, HDL-cholesterol, and triglycerides had further independent, though weaker, roles (R ² = 0.38). A subgroup of patients with a markedly higher progression rate (fast progressors) was clearly distinguishable considering these variables only (discrimination capacity from area under the receiver operating characteristic = 0.94). The proportion of fast progressors was reduced from 56% to 8-10% in subgroups in which only one trait among OGIS, GS, and CLIm was relatively stable (odds ratios 0.07-0.09). T2D polygenic risk score and baseline pancreatic fat, glucagon-like peptide 1, glucagon, diet, and physical activity did not show an independent role.

CONCLUSIONS

Deteriorating insulin sensitivity and β-cell function, increasing insulin clearance, high visceral or liver fat, and worsening of the lipid profile are the crucial factors mediating glycemic deterioration of patients with T2D in the initial phase of the disease. Stabilization of a single trait among insulin sensitivity, β-cell function, and insulin clearance may be relevant to prevent progression.

Antibiotics during childhood and development of appendicitis-a nationwide cohort study

BACKGROUND

Appendicitis is a common disease with a lifespan risk of approximately 8%. The full range of specific causes for the disease remains elusive, but an aberrant microbiota have been identified as a potential risk factor.

AIM

To investigate if use of antibiotics in a paediatric population increases the risk of appendicitis in childhood and adolescence METHODS: We conducted a cohort study from 1 January 1995 to 31 December 2014. A total of 1 385 707 children (0-19 years of age) including 7 406 397 antibiotic prescriptions and 11 861 cases of appendicitis were included. Primary outcome was appendicitis requiring appendectomy according to previous use of antibiotics. Appendicitis and appendectomy were identified from nationwide hospital records, and exposure to antibiotics was identified from nationwide prescription register. Rate ratios (RRs) with 95% confidence intervals were estimated from Poisson and logistic regression models.

RESULTS

Children who received at least one course of antibiotics were at increased risk of developing appendicitis compared to unexposed children (adjusted RR 1.72 [95% confidence interval 1.61-1.85]), mean age of developing appendicitis was 9.8 years (SD 4.1 years). The RR of appendicitis increased by 1.04 (1.04-1.04) per antibiotic course. A higher risk of appendicitis was observed in children exposed to antibiotics within the first 6 months of life (RR 1.46 [1.36-1.56]) and children exposed to broad-spectrum antibiotics (RR 1.33 [1.27-1.39]). After adjustment for number of antibiotic courses, the association between early age of antibiotic exposure and risk of appendicitis and the association between exposure to broad-spectrum antibiotics and the risk of appendicitis both disappeared.

CONCLUSION

Children who receive antibiotics are at increased and dose-dependent risk of appendicitis. The underlying mechanisms merit further investigation.

Stopping Mesalamine Therapy in Patients With Crohn's Disease Starting Biologic Therapy Does Not Increase Risk of Adverse Outcomes

BACKGROUND & AIMS

Little is known about the effects of discontinuing mesalamine therapy for patients with Crohn's disease (CD) who initiate therapy with an anti-tumor necrosis factor (anti-TNF) agent. We analyzed data from 2 national population cohorts to compare outcomes of patients with CD already on mesalamine therapy who started treatment with an anti-TNF agent and then either stopped or continued mesalamine.

METHODS

The primary outcome was any adverse clinical event, defined as a composite of new corticosteroid use or CD-related hospitalization or surgery. We collected data from the Truven MarketScan (IBM, Armonk, NY) health claims database in the United States and the Danish health registers. Our analysis included patients with CD who started anti-TNF therapy after at least 90 days of oral mesalamine therapy. Patients were classified as stopping mesalamine if therapy was discontinued within 90 days of starting anti-TNF. We performed multivariable Cox regression models controlling for demographics, clinical factors, and health care utilization. Adjusted hazard ratios with 95% CIs were calculated, comparing stopping mesalamine with continuing mesalamine.

RESULTS

A total of 3178 patients with CD were included in our final analysis (2960 in the United States and 218 in Denmark). Stopping mesalamine after initiating anti-TNF therapy was not associated with an increased risk of adverse clinical events in the US cohort (adjusted hazard ratio, 0.89; 95% CI, 0.77-1.03; P = .13) or in the Danish cohort (adjusted hazard ratio, 1.13; 95% CI, 0.68-1.87; P = .63). Similar results were obtained from sensitivity analyses of concomitant immunomodulator use and duration of mesalamine treatment before initiation of anti-TNF therapy.

CONCLUSIONS

In a retrospective analysis of 2 national databases, we found that stopping mesalamine therapy for patients with CD who were starting anti-TNF therapy did not increase their risk of adverse clinical events. These results should be validated in a prospective study.

Inflammatory Bowel Diseases Increase Risk of Type 2 Diabetes in a Nationwide Cohort Study

BACKGROUND & AIMS

The intestine regulates glucose homeostasis, but it is not clear whether chronic intestinal inflammation affects risk for type 2 diabetes. We investigated the long-term risk of type 2 diabetes in patients with inflammatory bowel diseases (IBD) in a nationwide cohort study in Denmark.

METHODS

In a nationwide population-based cohort of 6,028,844 persons in Denmark, we compared data from individuals with a diagnosis of IBD (Crohn's disease [CD] or ulcerative colitis UC]) with data from individuals from the general population from 1977 through 2014. Persons with type 2 diabetes were identified in the National Patient Register. Risk is presented as standardized incidence ratios (SIR) with 95% CIs.

RESULTS

During 736,072 person-years of follow-up, 3436 patients with IBD developed type 2 diabetes vs 2224 expected (SIR, 1.54; 95% CI, 1.49-1.60). The risk was significantly increased in patients with UC (SIR, 1.54; 95% CI, 1.48-1.60), in patients with CD (SIR, 1.57; 95% CI, 1.47-1.67), in women (SIR, 1.51; 95% CI, 1.44-1.59), and in men (SIR, 1.57; 95% CI, 1.50-1.65). The risk was highest the first year after a diagnosis of IBD (SIR, 4.48; 95% CI, 4.16-4.83), but remained increased for 20 or more years following the diagnosis (SIR, 1.26; 95% CI, 1.16-1.38). The increased risk could not be accounted for by frequency of health care contacts or corticosteroid exposure. Patients who received a diagnosis of IBD from 2003 through 2014 (SIR, 1.79; 95% CI, 1.67-1.91) had a significantly higher risk of type 2 diabetes than patients who received a diagnosis of IBD from 1977 through 1988 (SIR, 1.47; 95% CI, 1.39-1.56) or 1989 through 2002 (SIR, 1.48; 95% CI, 1.41-1.56) (P < .001).

CONCLUSIONS

In a population-based cohort study, we found an increased risk of type 2 diabetes in patients with UC or CD, with highest risk estimates from 2003 through 2014, compared with earlier years. Studies are needed to determine the effects of IBD treatment on risk of type 2 diabetes.

Risk of pancreatitis in patients with inflammatory bowel disease - a meta-analysis

INTRODUCTION

Patients with inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are believed to be at increased risk of pancreatitis. The objective of the present study was to investigate the association between IBD and risk of pancreatitis in a systematic review and meta-analysis.

METHODS

We conducted a systematic literature search in the PubMed and Embase databases. Data were extracted using predefined data fields, and risk of bias was assessed using the Risk of Bias Assessment tool for Non-randomized Studies. Random-effects meta-analyses were conducted.

RESULTS

Four studies with acute pancreatitis as outcome met the eligibility criteria. The overall estimated risk ratio revealed an increased risk for acute pancreatitis in patients with IBD of 2.78 (95% confidence interval (CI): 2.40-3.22). The risk ratio was increased for both CD and UC, with estimated risk ratios of 3.62 (95% CI: 2.99-4.38) and 2.24 (95% CI: 1.85-2.71), respectively. No studies meeting the eligibility criteria had chronic pancreatitis as outcome.

CONCLUSIONS

The risk of acute pancreatitis is increased in patients with IBD and higher for patients with CD. Due to the observational design of the studies included in our meta-analysis, the mechanisms underlying the increased risk of pancreatitis are unknown and remain to be investigated. Studies of the risk of chronic pancreatitis among patients with IBD are warranted.

FUNDING

This work was supported by a grant from the Novo Nordisk Foundation (NNF16OC0022586). The funder had no role in the study design, collection, analysis, interpretation of the data, or the writing of the manuscript.

TRIAL REGISTRATION

not relevant.

Gestational diabetes and the human salivary microbiota: a longitudinal study during pregnancy and postpartum

Background

An aberrant composition of the salivary microbiota has been found in individuals with type 2 diabetes, and in pregnant women salivary microbiota composition has been associated with preeclampsia and pre-term birth. Pregnant women, who develop gestational diabetes (GDM), have a high risk of developing type 2 diabetes after pregnancy. In the present study we assessed whether GDM is linked to variation in the oral microbial community by examining the diversity and composition of the salivary microbiota.

Method

In this observational study the salivary microbiota of pregnant women with GDM (n = 50) and normal glucose regulation (n = 160) in third trimester and 9 months postpartum was assessed by 16S rRNA gene amplicon sequencing of the V1-V3 region. GDM was diagnosed in accordance with the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria. Cross-sectional difference in alpha diversity was assessed using Student’s t-test and longitudinal changes were assessed by mixed linear regression. Cross-sectional and longitudinal difference in beta diversity was assessed by permutational multivariate analyses of variance. Differentially abundant genera and OTUs were identified by negative binomial regression.

Results

In the third trimester, two species-level operational taxonomic units (OTUs), while eight OTUs postpartum were differentially abundant in women with GDM compared with normoglycaemic women. OTU richness, Shannon diversity and Pielou evenness decreased from late pregnancy to 9 months after delivery regardless of glycaemic status.

Conclusion

GDM is associated with a minor aberration of the salivary microbiota during late pregnancy and postpartum. For unknown reasons richness of the salivary microbiota decreased from late pregnancy to postpartum, which might be explained by the physiological changes of the immune system during human pregnancy.

Anti-tumour necrosis factor-α therapy and recurrent or new primary cancers in patients with inflammatory bowel disease, rheumatoid arthritis, or psoriasis and previous cancer in Denmark: a nationwide, population-based cohort study

BACKGROUND

Safety of anti-tumour necrosis factor-α (TNFα) therapy in people with a history of cancer and with an immune-mediated disease is unknown. We aimed to assess the risk of recurrence of initial cancer or development of a new primary cancer after treatment with anti-TNFα therapy.

METHODS

In this Danish, population-based cohort study we recruited adults (≥18 years) with inflammatory bowel disease (IBD), rheumatoid arthritis, or psoriasis and a primary cancer diagnosed between Jan 1, 1999 and Dec 31, 2016. Patients were recruited from the prospectively recorded Danish National Patient Registry and the Danish Cancer Registry. Participants were matched 1:10 between the treatment group who received anti-TNFα therapy and the control group (no anti-TNFα therapy) and we excluded individuals with a cancer diagnosed before their first anti-TNFα treatment (or before matching date for controls), individuals diagnosed with IBD, rheumatoid arthritis, or psoriasis after anti-TNFα initiation (or respective match date for controls), and individuals who received anti-TNFα with fewer than five matched controls. Using adjusted Cox proportional hazards regression, we estimated the primary outcome of development of recurrent or new primary cancer in patients who received anti-TNFα therapy compared with patients who did not receive this therapy, matched by sex, immune-mediated disease type, cancer type, and time from initial cancer diagnosis to first anti-TNFα registration.

FINDINGS

Overall, 25 738 patients with immune-mediated disease and a history of cancer were identified. 434 patients who received anti-TNFα therapy after their initial cancer were matched to 4328 patients in the control group. During 18 752 person-years (median 5·6 years [IQR 2·8-7·9]) of follow up, 635 individuals developed recurrent or new primary cancer, 72 of whom had received anti-TNFα therapy and 563 of whom were in the control group. The median time between anti-TNFα treatment and recurrent or new primary cancer diagnosis was 2·8 years (IQR 1·7-5·4). The incidence of recurrent or new primary cancer development was 30·3 cases (95% CI 24·0-38·2) per 1000 person-years in the anti-TNFα treatment group and 34·4 cases (31·7-37·3) per 1000 person-years in the control group, yielding an adjusted hazard ratio of 0·82 (95% CI 0·61-1·11).

INTERPRETATION

Use of anti-TNFα therapy was not associated with recurrent or new primary cancer development in patients with previous cancer. Timing of anti-TNFα therapy after an initial cancer diagnosis did not influence recurrent or new primary cancer development. This observation might guide clinical decision making among providers treating immune-mediated diseases with anti-TNFα medications.

FUNDING

None.

Phosphatidylcholine and its relation to apolipoproteins A-1 and B changes after Roux-en-Y gastric bypass: a cohort study

Background

Phosphatidylcholine (PC), the most abundant of the phospholipids, has several metabolic functions in organs such as the liver and the intestine, important structural- and signaling functions in biological membranes, and might have a role in the effects of Roux-en-Y gastric bypass (RYGB), an operation known to ameliorate metabolic diseases, including type 2 diabetes. We hypothesized that serum PC, as a reflection of phospholipid metabolism, changes after RYGB, and that changes are related to weight loss and possibly to changes in glucose metabolism (reflected in the HbA1c-level) as well as to changes in serum Apo A1, Apo B and Apo B/Apo A1 ratio.

Methods

In a cohort of 220 RYGB patients, we studied changes in serum PC after RYGB in relation to serum Apo A1 and Apo B, the main apolipoproteins in HDL- and LDL/VLDL-particles, respectively, up to 2 years following RYGB-surgery.

Results

Serum PC reached its lowest levels 3 months postoperatively to later rebound to preoperative levels 24 months after RYGB. No difference was seen between patients with or without type 2 diabetes. Serum Apo A1 showed a similar pattern whereas serum Apo B concentrations stayed low after the initial decrease after RYGB. As a result, the Apo B / Apo A1 ratio constantly decreased during follow-up. There was a strong positive correlation between PC and Apo A1, and between PC and Apo B, but none between Apo A1 and Apo B. After RYGB surgery, both PC and Apo A1, but not Apo B, correlated positively to weight loss. In relation to total cholesterol, the molar ratio between serum PC and plasma cholesterol increased steadily after RYGB.

Conclusions

We conclude that changes in PC and apolipoproteins after RYGB are highly dynamic, reflecting a large plasticity and capability of accommodating lipid metabolism including PC-, cholesterol- and apolipoprotein metabolism imposed by RYGB surgery, independent of glucose tolerance. We suggest that after RYGB and major weight loss, PC and Apo A1 might have a special role in the altered metabolism of lipoproteins.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1111-7) contains supplementary material, which is available to authorized users.

Discovery of biomarkers for glycaemic deterioration before and after the onset of type 2 diabetes: descriptive characteristics of the epidemiological studies within the IMI DIRECT Consortium

AIMS/HYPOTHESIS

Here, we describe the characteristics of the Innovative Medicines Initiative (IMI) Diabetes Research on Patient Stratification (DIRECT) epidemiological cohorts at baseline and follow-up examinations (18, 36 and 48 months of follow-up).

METHODS

From a sampling frame of 24,682 adults of European ancestry enrolled in population-based cohorts across Europe, participants at varying risk of glycaemic deterioration were identified using a risk prediction algorithm (based on age, BMI, waist circumference, use of antihypertensive medication, smoking status and parental history of type 2 diabetes) and enrolled into a prospective cohort study (n = 2127) (cohort 1, prediabetes risk). We also recruited people from clinical registries with type 2 diabetes diagnosed 6-24 months previously (n = 789) into a second cohort study (cohort 2, diabetes). Follow-up examinations took place at ~18 months (both cohorts) and at ~48 months (cohort 1) or ~36 months (cohort 2) after baseline examinations. The cohorts were studied in parallel using matched protocols across seven clinical centres in northern Europe.

RESULTS

Using ADA 2011 glycaemic categories, 33% (n = 693) of cohort 1 (prediabetes risk) had normal glucose regulation and 67% (n = 1419) had impaired glucose regulation. Seventy-six per cent of participants in cohort 1 was male. Cohort 1 participants had the following characteristics (mean ± SD) at baseline: age 62 (6.2) years; BMI 27.9 (4.0) kg/m²; fasting glucose 5.7 (0.6) mmol/l; 2 h glucose 5.9 (1.6) mmol/l. At the final follow-up examination the participants' clinical characteristics were as follows: fasting glucose 6.0 (0.6) mmol/l; 2 h OGTT glucose 6.5 (2.0) mmol/l. In cohort 2 (diabetes), 66% (n = 517) were treated by lifestyle modification and 34% (n = 272) were treated with metformin plus lifestyle modification at enrolment. Fifty-eight per cent of participants in cohort 2 was male. Cohort 2 participants had the following characteristics at baseline: age 62 (8.1) years; BMI 30.5 (5.0) kg/m²; fasting glucose 7.2 (1.4) mmol/l; 2 h glucose 8.6 (2.8) mmol/l. At the final follow-up examination, the participants' clinical characteristics were as follows: fasting glucose 7.9 (2.0) mmol/l; 2 h mixed-meal tolerance test glucose 9.9 (3.4) mmol/l.

CONCLUSIONS/INTERPRETATION

The IMI DIRECT cohorts are intensely characterised, with a wide-variety of metabolically relevant measures assessed prospectively. We anticipate that the cohorts, made available through managed access, will provide a powerful resource for biomarker discovery, multivariate aetiological analyses and reclassification of patients for the prevention and treatment of type 2 diabetes.

Metformin-induced changes of the gut microbiota in healthy young men: results of a non-blinded, one-armed intervention study

AIMS/HYPOTHESIS

Individuals with type 2 diabetes have an altered bacterial composition of their gut microbiota compared with non-diabetic individuals. However, these alterations may be confounded by medication, notably the blood-glucose-lowering biguanide, metformin. We undertook a clinical trial in healthy and previously drug-free men with the primary aim of investigating metformin-induced compositional changes in the non-diabetic state. A secondary aim was to examine whether the pre-treatment gut microbiota was related to gastrointestinal adverse effects during metformin treatment.

METHODS

Twenty-seven healthy young Danish men were included in an 18-week one-armed crossover trial consisting of a pre-intervention period, an intervention period and a post-intervention period, each period lasting 6 weeks. Inclusion criteria were men of age 18-35 years, BMI between 18.5 kg/m² and 27.5 kg/m², HbA_1c < 39 mmol/mol (5.7%) and plasma creatinine within the normal range. No prescribed medication, including antibiotics, for 2 months prior to recruitment were allowed and no previous gastrointestinal surgery, discounting appendectomy or chronic illness requiring medical treatment. During the intervention the participants were given metformin up to 1 g twice daily. Participants were examined five times in the fasting state with blood sampling and recording of gastrointestinal symptoms. Examinations took place at Frederiksberg Hospital, Denmark before and after the pre-intervention period, halfway through and immediately after the end of intervention and after the wash-out period. Faecal samples were collected at nine evenly distributed time points, and bacterial DNA was extracted and subjected to 16S rRNA gene amplicon sequencing in order to evaluate gut microbiota composition. Subjective gastrointestinal symptoms were reported at each visit.

RESULTS

Data from participants who completed visit 1 (n=23) are included in analyses. For the primary outcome the relative abundance of 11 bacterial genera significantly changed during the intervention but returned to baseline levels after treatment cessation. In line with previous reports, we observed a reduced abundance of Intestinibacter spp. and Clostridium spp., as well as an increased abundance of Escherichia/Shigella spp. and Bilophila wadsworthia. The relative abundance at baseline of 12 bacterial genera predicted self-reported gastrointestinal adverse effects.

CONCLUSIONS/INTERPRETATION

Intake of metformin changes the gut microbiota composition in normoglycaemic young men. The microbiota changes induced by metformin extend and validate previous reports in individuals with type 2 diabetes. Secondary analyses suggest that pre-treatment gut microbiota composition may be a determinant for development of gastrointestinal adverse effects following metformin intake. These results require further investigation and replication in larger prospective studies.

TRIAL REGISTRATION

Clinicaltrialsregister.eu 2015-000199-86 and ClinicalTrials.gov NCT02546050 FUNDING: This project was funded by Danish Diabetes Association and The Novo Nordisk Foundation.

Associations between adult height and type 2 diabetes mellitus: a systematic review and meta-analysis of observational studies

Background

Although short adult height is generally associated with increased risks of type 2 diabetes mellitus (T2DM), there are large inconsistencies across studies. The aims of this study were to describe and quantify currently available evidence on the association between adult height and T2DM, to examine whether the reported associations differ by sex, and to examine the shapes of the height and T2DM associations.

Methods

Relevant literature was identified using PubMed (1966–May 2018), EMBASE (1947–May 2018) and Google Scholar (May 2018). We identified cross-sectional and cohort studies with original publications on human subjects, which were included in a random-effects meta-analysis.

Results

From 15 971 identified sources, 25 studies met the inclusion criteria for the systematic review (N=401 562 individuals). From these 25 studies, 16 (9 cross-sectional studies and 7 cohort studies) were included in the meta-analysis (n=261 496 individuals). The overall random-effects meta-analysis indicated an inverse association between adult height and T2DM (effect estimate=0.88, 95% CI 0.81 to 0.95). No sex differences in the associations between adult height and T2DM were found (effect estimate for men: 0.86, 95% CI 0.75 to 0.99; effect estimate for women: 0.90; 95% CI 0.80 to 1.01; p value for sex interaction=0.80). Due to lack of data, results on the shape of the association between height and T2DM were inconclusive.

Conclusions

Shorter height is associated with an increased risk of T2DM and the association does not significantly differ by sex. The currently available data are insufficient to support conclusions regarding the shape of the association between height and T2DM.

Trial registration number

CRD42017062446.

Cardiovascular Risk Profile Among Patients With Inflammatory Bowel Disease: A Population-based Study of More Than 100 000 Individuals

BACKGROUND AND AIMS

Patients with inflammatory bowel disease have increased risks of cardiovascular diseases, but the role of traditional and non-traditional cardiovascular risk factors remains unclear. We investigated if the cardiovascular risk profile differs between patients with inflammatory bowel disease and individuals in the general population.

METHODS

We included a population of 108789 participants from the Copenhagen General Population Study of individuals of Danish descent aged 20-100 years. The population included 1203 individuals with prevalent inflammatory bowel disease [347 with Crohn's disease and 856 with ulcerative colitis]. The cardiovascular risk profile was assessed by traditional risk factors [plasma lipids and glucose, body composition measures, and blood pressure] and non-traditional risk factors [inflammatory markers and biomarkers of liver and pancreas function].

RESULTS

Even though patients with inflammatory bowel disease more frequently are diagnosed with cardiovascular diseases, traditional cardiovascular risk factors were not increased. Indeed, patients with inflammatory bowel disease had slightly lower plasma levels of total cholesterol and low-density lipoprotein cholesterol. Levels of inflammatory markers, particularly high-sensitivity C-reactive protein, were higher in individuals with versus without a diagnosis of inflammatory bowel disease, when assessed at a random point in time during the disease course.

CONCLUSIONS

The increased risk of cardiovascular diseases in patients with inflammatory bowel disease may be linked to chronic systemic inflammation rather than to traditional cardiovascular risk factors. Further studies need to examine whether cardiovascular-preventive strategies should focus on optimising management of inflammation in patients with inflammatory bowel disease rather than focusing on traditional cardiovascular risk factors.

The effect of drinking water pH on the human gut microbiota and glucose regulation: results of a randomized controlled cross-over intervention

Studies in rodent models have shown that alterations in drinking water pH affect both the composition of the gut microbiota and host glucose regulation. To explore a potential impact of electrochemically reduced alkaline (pH ≈ 9) versus neutral (pH ≈ 7) drinking water (2 L/day) on human intestinal microbiota and host glucose metabolism we conducted a randomized, non-blinded, cross-over study (two 2-week intervention periods, separated by a 3-week wash-out) in 29 healthy, non-smoking Danish men, aged 18 to 35 years, with a body mass index between 20.0 to 27.0 kg m-2. Volunteers were ineligible if they had previously had abdominal surgery, had not been weight stabile for at least two months, had received antibiotic treatment within 2 months, or had a habitual consumption of caloric or artificially sweetened beverages in excess of 1 L/week or an average intake of alcohol in excess of 7 units/week. Microbial DNA was extracted from faecal samples collected at four time points, before and after each intervention, and subjected to 16S rRNA gene amplicon sequencing (Illumina MiSeq, V4 region). Glycaemic regulation was evaluated by means of an oral glucose tolerance test.No differential effect of alkaline versus neutral drinking water was observed for the primary outcome, overall gut microbiota diversity as represented by Shannon's index. Similarly, neither a differential effect on microbiota richness or community structure was observed. Nor did we observe a differential effect on the abundance of individual operational taxonomic units (OTUs) or genera. However, analyses of within period effects revealed a significant (false discovery rate ≤5%) increase in the relative abundance of 9 OTUs assigned to order Clostridiales, family Ruminococcaceae, genus Bacteroides, and species Prevotella copri, indicating a potential effect of quantitative or qualitative changes in habitual drinking habits. An increase in the concentration of plasma glucose at 30 minutes and the incremental area under the curve of plasma glucose from 0 30 and 0 120 minutes, respectively, was observed when comparing the alkaline to the neutral intervention. However, results did not withstand correction for multiplicity. In contrast to what has been reported in rodents, a change in drinking water pH had no impact on the composition of the gut microbiota or glucose regulation in young male adults. The study is registered at www.clinicaltrials.gov (NCT02917616).

Increase in clinically recorded type 2 diabetes after colectomy

The colon hosts gut microbes and glucagon-like peptide 1 secreting cells, both of which influence glucose homeostasis. We tested whether colectomy is associated with development of type 2 diabetes. Using nationwide register data, we identified patients who had undergone total colectomy, partial colectomy, or proctectomy. For each colectomy patient, we selected 15 non-colectomy patients who had undergone other surgeries. Compared with non-colectomy patients, patients with total colectomy (n = 3,793) had a hazard ratio (HR) of clinically recorded type 2 diabetes of 1.40 (95% confidence interval [CI], 1.21 to 1.62; p<0.001). Corresponding HRs after right hemicolectomy (n = 10,989), left hemicolectomy (n = 2,513), and sigmoidectomy (n = 13,927) were 1.08 (95% CI, 0.99 to 1.19; p=0.10), 1.41 (95% CI, 1.19 to 1.67; p<0.001) and 1.30 (95% CI, 1.21 to 1.40; p<0.001), respectively. Although we were not able to adjust for several potential confounders, our findings suggest that the left colon may contribute to maintenance of glucose homeostasis.

Recovery of gut microbiota of healthy adults following antibiotic exposure

To minimize the impact of antibiotics, gut microorganisms harbour and exchange antibiotics resistance genes, collectively called their resistome. Using shotgun sequencing-based metagenomics, we analysed the partial eradication and subsequent regrowth of the gut microbiota in 12 healthy men over a 6-month period following a 4-day intervention with a cocktail of 3 last-resort antibiotics: meropenem, gentamicin and vancomycin. Initial changes included blooms of enterobacteria and other pathobionts, such as Enterococcus faecalis and Fusobacterium nucleatum, and the depletion of Bifidobacterium species and butyrate producers. The gut microbiota of the subjects recovered to near-baseline composition within 1.5 months, although 9 common species, which were present in all subjects before the treatment, remained undetectable in most of the subjects after 180 days. Species that harbour β-lactam resistance genes were positively selected for during and after the intervention. Harbouring glycopeptide or aminoglycoside resistance genes increased the odds of de novo colonization, however, the former also decreased the odds of survival. Compositional changes under antibiotic intervention in vivo matched results from in vitro susceptibility tests. Despite a mild yet long-lasting imprint following antibiotics exposure, the gut microbiota of healthy young adults are resilient to a short-term broad-spectrum antibiotics intervention and their antibiotics resistance gene carriage modulates their recovery processes.

Population-based studies of relationships between dietary acidity load, insulin resistance and incident diabetes in Danes

BACKGROUND

It has been suggested that the acidity of the diet may be related to increased risk of type 2 diabetes. To investigate this hypothesis, we tested if the acidity of the diet, measured as the Potential Renal Acid Load (PRAL) score, was associated with incident diabetes and diabetes-related intermediary traits.

METHODS

A total of 54,651 individuals from the Danish Diet, Cancer and Health (DCH) cohort were included in the prospective cox regression analyses of incident diabetes over a 15 years follow-up period. Moreover, 5724 Danish individuals with baseline data from the Inter99 cohort were included in the cross sectional, multivariate and logistic regression analyses of measures of insulin sensitivity, insulin release and glucose tolerance status derived from an oral glucose tolerance test (OGTT).

RESULTS

In the DCH cohort a trend analysis showed that quintiles of PRAL score were, after multifactorial adjustment, associated with a higher incidence of diabetes (p_trend = 6 × 10^- 7). HR for incident diabetes was 1.24 (1.14; 1.35) (p = 7 × 10^- 7) between first and fifth PRAL score quintile. In Inter99 higher PRAL score associated with insulin resistance as estimated by lower BIGTT-Si (an OGTT-derived index of insulin sensitivity) (p = 4 × 10^- 7) and Matsuda index of insulin sensitivity (p = 2 × 10^- 5) as well as higher HOMA-IR (p = 0.001). No association was observed for measures of insulin release, but higher PRAL score was associated with lower OGTT-based disposition index.

CONCLUSIONS

A high dietary acidity load is associated with a higher risk of diabetes among middle-aged Danes. Although adjustment for BMI attenuated the effect sizes the association remained significant. The increased risk of diabetes may be related to our finding that a high dietary acidity load associates with impaired insulin sensitivity.

Antibiotic exposure in early life and childhood overweight and obesity: A systematic review and meta-analysis

We conducted a systematic review and meta-analysis of observational studies investigating the association between antibiotic exposure in infancy and risk of childhood overweight and obesity. Thirteen studies, including a total of 527 504 children, were included in the systematic review and 8 were included in meta-analyses. Exposure to antibiotics in infancy was associated with an increased odds ratio (OR) of childhood overweight and obesity (OR 1.11, 95% confidence interval [CI] 1.02-1.20). Whereas exposure to 1 treatment only and exposure between 6 and 24 months were not associated with increased risk of childhood overweight and obesity, exposure to >1 treatment was associated with an OR of 1.24 (95% CI 1.09-1.43) and exposure within the first 6 months of life was associated with an OR of 1.20 (95% CI 1.04-1.37). In conclusion, antibiotic exposure in infancy was associated with a slightly increased risk of childhood overweight and obesity, mainly if children were exposed to repeated treatments or treatment within the first 6 months of life. It is unclear whether this association is mediated via direct effects of antibiotics on the gut microbiota.

Aberrant intestinal microbiota in individuals with prediabetes

AIMS/HYPOTHESIS

Individuals with type 2 diabetes have aberrant intestinal microbiota. However, recent studies suggest that metformin alters the composition and functional potential of gut microbiota, thereby interfering with the diabetes-related microbial signatures. We tested whether specific gut microbiota profiles are associated with prediabetes (defined as fasting plasma glucose of 6.1-7.0 mmol/l or HbA_1c of 42-48 mmol/mol [6.0-6.5%]) and a range of clinical biomarkers of poor metabolic health.

METHODS

In the present case-control study, we analysed the gut microbiota of 134 Danish adults with prediabetes, overweight, insulin resistance, dyslipidaemia and low-grade inflammation and 134 age- and sex-matched individuals with normal glucose regulation.

RESULTS

We found that five bacterial genera and 36 operational taxonomic units (OTUs) were differentially abundant between individuals with prediabetes and those with normal glucose regulation. At the genus level, the abundance of Clostridium was decreased (mean log₂ fold change -0.64 (SEM 0.23), p _adj  = 0.0497), whereas the abundances of Dorea, [Ruminococcus], Sutterella and Streptococcus were increased (mean log₂ fold change 0.51 (SEM 0.12), p _adj  = 5 × 10^-4; 0.51 (SEM 0.11), p _adj  = 1 × 10^-4; 0.60 (SEM 0.21), p _adj  = 0.0497; and 0.92 (SEM 0.21), p _adj  = 4 × 10^-4, respectively). The two OTUs that differed the most were a member of the order Clostridiales (OTU 146564) and Akkermansia muciniphila, which both displayed lower abundance among individuals with prediabetes (mean log₂ fold change -1.74 (SEM 0.41), p _adj  = 2 × 10^-3 and -1.65 (SEM 0.34), p _adj  = 4 × 10^-4, respectively). Faecal transfer from donors with prediabetes or screen-detected, drug-naive type 2 diabetes to germfree Swiss Webster or conventional C57BL/6 J mice did not induce impaired glucose regulation in recipient mice.

CONCLUSIONS/INTERPRETATION

Collectively, our data show that individuals with prediabetes have aberrant intestinal microbiota characterised by a decreased abundance of the genus Clostridium and the mucin-degrading bacterium A. muciniphila. Our findings are comparable to observations in overt chronic diseases characterised by low-grade inflammation.