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Diabetes and RA: Further Explanations for Comorbidity

This post was last updated on December 2, 2019 at 9:41 pm

Doctor speaking with man

Why, how, and what might be next?

By Jason Bhan, MD, Fernando Schwartz, PhD, and Lauren Wiener

If you’ve been following along with us through this series, you know the team at Prognos has been investigating diabetes and rheumatoid arthritis.  Our goal has been to find evidence that diabetes and RA, which are both systemic inflammatory diseases, are also comorbid conditions, while also investigating how this is impacted by disease severity.

In our last blog, we talked you through how our analysis did find evidence of a diabetes and rheumatoid arthritis comorbidity.  Within the Prognos Registry, nearly 30% of patients suffering from RA also suffer from diabetes.  We also found that those RA patients with a double positive diagnosis were actually less likely to also suffer from diabetes.

What This Means

The results of our comorbidity analysis show a strong comorbidity between diabetes and RA, which has yet to be reported with a sample size on this scale. A striking 28.79% of RA patients were found to be diagnosed with diabetes, and 2.51% of diabetes patients were found to have RA. These significant comorbidities could be reflected in standards of care, which would enable physicians to more effectively monitor their diabetes or RA patients for progression of the other disease.

We must admit, it was somewhat surprising to find that a double positive diagnosis was more common in patients who are diagnosed with only RA as compared to comorbid patient with diabetes and RA. Furthermore, our p value was very strong and the observed difference of double positive diagnosis between the two populations is statistically significant. There are a variety of reasons why we may have observed such a difference between a population with only RA and a comorbid population.

One possibility is that this difference is associated with lifestyle choices. It is possible that patients who are more conscious of their health go to the doctor more frequently for tests and monitoring of their RA and are more likely to catch a double positive diagnosis. This health-conscious and doctor compliant population could also be less likely to have diabetes.

Another particularly exciting possibility is that our analysis has uncovered a true independent difference between comorbid and RA only patients. Perhaps diabetes provides some sort of protection against having a double positive RA diagnosis.

What’s Next

The results of our investigation certainly beg the question “what’s next?”.  While we can’t say for sure, our comorbidity results could be reflected in standards of care in the future. Physicians could monitor diabetic patients for progression of RA, which can benefit from early intervention.

If we were to further our investigation, an interesting direction for Prognos to pursue could be to only include patients that are diagnosed with RA by lab tests, and exclude patients diagnosed by only ICD codes. This approach could yield more accurate rates of a double positive diagnosis, and could ameliorate the bias over-reporting non-double positive RA patients.

Another option would be further research and consultation with endocrine and rheumatology specialists to examine the possibility of a physiological relationship between a double positive diagnosis and diabetes. A physiological link may explain why a double positive diagnosis would be less common in a comorbid population than a population of patients with only RA.

Thanks for Reading!

>We appreciate your joining us to explore the comorbidity between diabetes and RA.  As always, we encourage you to follow along with us and to reach out to us with questions or to request additional information.

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