Search

Background: Co-occurrence of inflammatory bowel disease (IBD) and type 1 diabetes (T1D) has been linked to poor clinical outcomes, but evidence on their bidirectional associations remain scarce. This study aims to investigate their bidirectional associations., Methods: A nationwide matched cohort and case-control study with IBD patients identified between 1987 and 2017. The cohort study included 20,314 IBD patients (≤28 years; Crohn's disease [CD, n = 7277], ulcerative colitis [UC, n = 10,112], and IBD-unclassified [IBD-U, n = 2925]) and 99,200 individually matched reference individuals, with a follow-up until December 2021. The case-control study enrolled 87,001 IBD patients (no age restriction) and 431,054 matched controls. We estimated adjusted hazard ratio (aHR) of incident T1D in the cohort study with flexible parametric survival model and adjusted odds ratio (aOR) of having a prior T1D in the case-control study with conditional logistic regression model, with 95% confidence intervals (CI)., Findings: During a median follow-up of 14 years, 116 IBD patients and 353 reference individuals developed T1D. Patients with IBD had a higher hazard of developing T1D (aHR = 1.58 [95% CI = 1.27-1.95]). The hazard was increased in UC (aHR = 2.02 [1.51-2.70]) but not in CD or IBD-U. In the case-control study, a total of 1018 (1.2%) IBD patients and 3496 (0.8%) controls had been previously diagnosed with T1D. IBD patients had higher odds of having prior T1D (aOR = 1.36 [1.26-1.46]). Such positive association was observed in all IBD subtypes. The sibling comparison analyses showed similar associations between IBD and T1D (aHR = 1.44 [0.97-2.15] and aOR = 1.32 [1.18-1.49])., Interpretation: Patients with IBD had a moderately increased hazard of developing T1D and higher odds of having prior T1D. Their bidirectional associations may be partially independent of shared familial factors., Funding: European Crohn's and Colitis Organisation, Stiftelsen Professor Nanna Svartz Fond, SSMF (project#: PG-23-0315-H-02), Ruth and Richard Julin Foundation; and FORTE (project#: 2016-00424)., Competing Interests: All authors have completed the ICMJE uniform disclosure form and declare: OO has been PI on projects at Karolinska Institutet financed by grants from Janssen, Pfizer, AbbVie, Takeda, Galapagos/Alfasigma, Ferring, and Bristol Myer Squibb. JH served as speaker and/or advisory board member for AbbVie, BMS, Celltrion, Eli Lilly, Ferring, Galapagos, Gilead, Index Pharma, Janssen, Medtronic, Merck, MSD, Novartis, Pfizer, Sandoz, Shire, Takeda, Thermo Fisher Scientific, Tillotts Pharma, and Vifor Pharma and received grant support from Takeda, Janssen, and MSD. FE has served as an advisory board member for Boehringer Ingelheim. JFL has coordinated a study on behalf of the Swedish IBD quality register (SWIBREG). That study received funding from Janssen Corporation. JFL has also received financial support from MSD developing a paper reviewing national healthcare registers in China. JFL has a research collaboration on celiac disease with Takeda. The other authors report no disclosures relevant to the manuscript., (© 2024 The Author(s).)

Objectives: Crohn's disease (CD) is characterized by overproduction of proinflammatory cytokines like interleukin (IL)-1beta. Production of mature IL-1beta is dependent on a caspase-1-activating protein complex called the NALP3 inflammasome, composed of NALP3, ASC, and CARD8. NALP3 shares structural similarities with Nod2, and both of these proteins are required for bacteria-induced IL-1beta secretion. The combination of the polymorphisms CARD8 (C10X)and NALP3 (Q705K) was recently shown to be associated with rheumatoid arthritis.Our aim was to investigate whether these combined polymorphisms play a role in the susceptibility to CD., Methods: The study included 498 CD patients in two cohorts from different regions and 742 control individuals from a Swedish population. DNA was isolated from whole blood. Polymorphisms of (Q705K) NALP3 and (C10X) CARD8, as well as the Nod2 variants, R702W and G908R, were genotyped using the Taqman single nucleotide polymorphism assay. The Nod2 frameshift mutation, L1007fs, was detected by Megabace SNuPe genotyping., Results: Our results show that men who have both the C10X and Q705K alleles in CARD8 and NALP3, and who express wild-type alleles of Nod2 are at an increased risk of developing CD (odds ratio, OR: 3.40 range: 1.32-8.76); P = 0.011). No association with these polymorphisms was found in women (OR: 0.89 (range: 0.44-1.77); P = 0.74)., Conclusions: We suggest a role for combined polymorphisms in CARD8 and NALP3 in the development of CD in men, with obvious sex differences in the genetic susceptibility pattern. These findings give further support to the importance of innate immune responses in CD.