Hansjörg Baurecht1, Dennis Freuer2, Christine Welker1, Lam C Tsoi3,4,5, James T Elder3,6, Benjamin Ehmke7, Michael F Leitzmann1, Birte Holtfreter8, Sebastian-Edgar Baumeister9. 1. Department of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany. 2. Chair of Epidemiology, University of Augsburg, University Hospital Augsburg, Augsburg, Germany. 3. Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA. 4. Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA. 5. Department of Biostatistics, Center for Statistical Genetics, University of Michigan, Ann Arbor, Michigan, USA. 6. Ann Arbor Veterans Affairs Hospital, Ann Arbor, Michigan, USA. 7. Clinic for Periodontology and Conservative Dentistry, University of Münster, Münster, Germany. 8. Department of Restorative Dentistry, Periodontology, Endodontology, and Preventive and Pediatric Dentistry, University Medicine Greifswald, Greifswald, Germany. 9. Institute of Health Services Research in Dentistry, University of Münster, Münster, Germany.
Abstract
AIM: Observational research suggests that periodontitis affects psoriasis. However, observational studies are prone to reverse causation and confounding, which hampers drawing causal conclusions and the effect direction. We applied the Mendelian randomization (MR) method to comprehensively assess the potential bi-directional association between periodontitis and psoriasis. MATERIALS AND METHODS: We used genetic instruments from the largest available genome-wide association study of European descent for periodontitis (17,353 cases, 28,210 controls) to investigate the relationship with psoriasis (13,229 cases, 21,543 controls), and vice versa. Causal Analysis Using Summary Effect (CAUSE) estimates and inverse variance-weighted (IVW) MR analyses were used for the primary analysis. Robust MR approaches were used for sensitivity analyses. RESULTS: Both univariable methods, CAUSE and IVW MR analyses, did not reveal any impact of periodontitis on psoriasis (CAUSE odds ratio [OR] = 1.00, p = 1.00; IVW OR = 1.02, p = .6247), or vice versa (CAUSE OR = 1.01, p = .5135; IVW OR = 1.00, p = .7070). The null association was corroborated by pleiotropy-robust methods with ORs close to 1 and p-values >.59. Overall, MR analyses did not suggest any effect of periodontitis on psoriasis. Similarly, there was no evidence to support an effect of psoriasis on periodontitis. CONCLUSIONS: Within the limitations of this MR study, the outcomes supported neither periodontitis affecting psoriasis nor psoriasis affecting periodontitis.
AIM: Observational research suggests that periodontitis affects psoriasis. However, observational studies are prone to reverse causation and confounding, which hampers drawing causal conclusions and the effect direction. We applied the Mendelian randomization (MR) method to comprehensively assess the potential bi-directional association between periodontitis and psoriasis. MATERIALS AND METHODS: We used genetic instruments from the largest available genome-wide association study of European descent for periodontitis (17,353 cases, 28,210 controls) to investigate the relationship with psoriasis (13,229 cases, 21,543 controls), and vice versa. Causal Analysis Using Summary Effect (CAUSE) estimates and inverse variance-weighted (IVW) MR analyses were used for the primary analysis. Robust MR approaches were used for sensitivity analyses. RESULTS: Both univariable methods, CAUSE and IVW MR analyses, did not reveal any impact of periodontitis on psoriasis (CAUSE odds ratio [OR] = 1.00, p = 1.00; IVW OR = 1.02, p = .6247), or vice versa (CAUSE OR = 1.01, p = .5135; IVW OR = 1.00, p = .7070). The null association was corroborated by pleiotropy-robust methods with ORs close to 1 and p-values >.59. Overall, MR analyses did not suggest any effect of periodontitis on psoriasis. Similarly, there was no evidence to support an effect of psoriasis on periodontitis. CONCLUSIONS: Within the limitations of this MR study, the outcomes supported neither periodontitis affecting psoriasis nor psoriasis affecting periodontitis.
Authors: Julie T Marchesan; Mustafa Saadat Girnary; Kevin Moss; Eugenia Timofeev Monaghan; Grant Joseph Egnatz; Yizu Jiao; Shaoping Zhang; Jim Beck; Karen V Swanson Journal: Periodontol 2000 Date: 2020-02 Impact factor: 7.589
Authors: Stephen Burgess; George Davey Smith; Neil M Davies; Frank Dudbridge; Dipender Gill; M Maria Glymour; Fernando P Hartwig; Michael V Holmes; Cosetta Minelli; Caroline L Relton; Evropi Theodoratou Journal: Wellcome Open Res Date: 2020-04-28