Impact of comorbidities on the disability progression in multiple sclerosis

Objectives Investigation of the comorbidity burden in persons with multiple sclerosis (PwMS) has become increasingly important. The aim of this study was to investigate the relationships of cardiovascular disease (CVD) comorbidities and type 2 diabetes with the disability progression. Materials & Methods The retrospective cohort study was conducted at the Clinic of Neurology, Belgrade. The Belgrade MS population Registry, which comprises 2725 active MS cases, was used as the source of data. The mean duration of the disease was 21.6 +/- 12.5 years. Expanded Disability Status Scale (EDSS) was followed in all PwMS in the Registry. In the statistical analysis, the Cox proportional hazard regression analysis and Kaplan-Meier curve were performed. Results Hypertension statistically significantly contributed to more rapid reaching investigated levels of irreversible disability (EDSS 4.0, 6.0, and 7.0), while the presence of any of the investigated CVD comorbidities and type 2 diabetes significantly contributed to faster reaching EDSS 4.0 and EDSS 6.0. In a multivariable model, progression index (PI) was singled out (HR = 3.171, p < .001), indicating that higher progression index (PI) was an independent predictor of CVD occurrence in MS patients. In the case of type 2 diabetes, PI (p < .001) and MS phenotype (p = .015) were statistically significant in multivariable Cox regression analysis. Conclusions Our study confirms the impact of CVD comorbidities and type 2 diabetes in MS on the progression of disability as measured by EDSS in the large cohort of PwMS from the population Registry.

Automated summary

The study found that hypertension significantly accelerated reaching irreversible disability levels (EDSS 4.0, 6.0, and 7.0), while the presence of any cardiovascular disease comorbidities and type 2 diabetes significantly accelerated reaching EDSS 4.0 and EDSS 6.0. In a multivariable model, higher progression index (PI) was identified as an independent predictor of cardiovascular disease occurrence in multiple sclerosis (MS) patients. In the case of type 2 diabetes, PI and MS phenotype were statistically significant in multivariable Cox regression analysis.