In this study, the prevalence of IBD patients with multimorbidity, defined as two or more comorbidities in the same individual, excluding IBD was 10.3%. We also showed that 23.9% of IBD patients had at least one comorbidity. Patients with UC were more likely to have multimorbidity than patients with CD (46.8% vs 44.3%; P = 0.009). Although published research on comorbidities among IBD patients is limited, our findings agree with a previous Finnish study by Johanna et al. (13) reporting a percentage of 29% of IBD patients with at least one comorbidity. A further Swiss study by Carolin et al. (12) reported a percentage of 78% of IBD patients with at least one comorbidity, and a median of three comorbidities. The latter study also concluded that IBD patients have a higher prevalence of comorbidities compared to non-IBD patients. We believe that the variation in the proportions of IBD patients with comorbidities in the literature is due to the differences in the average age of IBD patients in each study as older IBD patients are generally more likely to have other age-related comorbidities.
Characterization of the comorbidities among patients with IBD is clinically relevant. We found that DM was the most common comorbidity among IBD patients (4.9%). In contrast, the Swiss study (12) found that DM was the eighth most common comorbidity among IBD patients with cardiovascular disorders being the most common comorbidity. The Finnish study (13) ranked DM fifth and chronic hypertension first in the comorbidities list among IBD patients. The different rankings of comorbidities among IBD patients can be explained by the natural epidemiological difference of diseases in different populations around the world. Moreover, the ranking of DM as the most common comorbidity in our study could point towards the high prevalence of DM in the general population of Saudi Arabia (14, 15).
One of the significant statistical relationships we found in our sample is the relationship of multimorbidity and the occurrence of thrombosis (P < 0.000). This finding was also supported by several studies (16, 17) which have shown an increased risk of venous thromboembolism (VTE) in patients with IBD. One cohort study showed a higher 3-year incidence of recurrent thrombosis in multimorbid patients (18). However, dissimilar to our sample, the previously mentioned cohort study included acute VTE patients aged ≥ 65 years. Interestingly, our sample also showed a statical significance despite it not being formed of mainly old age patients with previous VTE. Since multimorbidity in IBD patients and thrombosis were statistically associated, physician should also have low threshold for suspecting thrombotic events in the multimorbid IBD population. Furthermore, we believe that developing a specialized criteria for multimorbidity in IBD patients would be a beneficial tool to assess the risk of thrombosis and enhance the overall management of IBD patients.
The prevalence of multimorbidity in IBD patients is considerably worrisome as concomitant comorbidities can strongly influence the quality of life negatively in IBD patients (12). Physicians treating IBD patients should be aware that appropriate management of comorbidities in IBD patients can lead to better IBD management outcomes and enhanced holistic patient-centered care. Furthermore, identifying certain comorbidities could significantly impact treatment selection, specifically by avoiding medications that predispose to infections or even thrombosis. For example, patients who are older than 55 and have DM might be better served by treatment with a leukocyte trafficking inhibitor such as vedolizumab rather than an anti-tumor necrosis factor agent (anti-TNF), which have been associated with higher risk of serious infections (19). A recent recommendation by the European Crohn’s and Colitis Organization (ECCO) suggested that the use of Janus kinase inhibitor tofacitinib should be avoided in elderly patients who have multiple cardiovascular risk factors as data from open label studies conducted in rheumatoid arthritis suggest a higher risk of venous thromboembolism in this patient cohort (20).
There is also increasing evidence to support a plausible association between IBD and several comorbidities, related to poor disease outcomes, higher mortality, and increased hospitalization rates (2, 12). We suggest further research on the prevalence of multimorbidity among IBD patients on wider scales in terms of both sample size and demographics, and we also urge researchers to further investigate the effects of multimorbidity and polypharmacy on IBD patients. Major strengths of the present study include the limited published research on the topic of multimorbidity among IBD patients and the reliable comprehensive data set available for analyses. Nevertheless, a major limitation of our study is the usual challenge in retrospective studies to obtain accurate conclusive patient outcomes and to determine the precise timeline of events after the diagnosis. Another major limitation is the absence of some variables such as the type and number of IBD medications and non-IBD medications used in different time points which would have been beneficial in assessing the impact of polypharmacy on IBD course, management and patient care outcomes.
In conclusion, our findings demonstrate that multimorbidity is not uncommon among IBD patients, especially females diagnosed with UC. Thrombosis and multimorbidity in IBD were statistically associated; therefore, scales for the assessment of thrombosis might be beneficial for improving the overall management of multimorbid IBD patients. Our study also highlights the importance of recognizing common comorbidities in IBD patients to develop a multidisciplinary management approach. Future studies evaluating the impact of multimorbidity on IBD course, management and patient care outcomes are needed to enhance the holistic care of patients.