The presence of cardiovascular disease (CVD) comorbidities and type 2 diabetes (T2D) increased the rate of disability progression in patients with MS, according to study findings published in Acta Neurologica Scandinavica.

For the retrospective cohort study, researchers aimed to determine the impact of CVD comorbidities—including hypertension, hyperlipidemia, ischemic heart disease, and cerebrovascular disease, and T2D—on disability progression in MS. The study team used an MS population registry that included 2,725 active cases as the data source. The Expanded Disability Status Scale (EDSS) was reported for all patients in the registry.

The mean duration of disease was 21.6±12.5 years. Most participants (69.8%) were women, and the mean age was 55.8 years. Relapsing-remitting MS was the most common phenotype (62.9%), followed by secondary progressive (24.1%) and primary progressive (13.0%). Median EDSS at baseline was 4.00. Among participants, 311 (11.4%) had one CVD comorbidity, 43 had two (1.6%), and six (0.2%) had three. T2D was reported in 56 patients (2.1%).

Hypertension had a statistically significantly impact on more rapid progression to investigated levels of irreversible disability. Further, the incidence of any CVD comorbidity and T2D had a significant impact on more rapid progression to EDSS 4.0 and EDSS 6.0. Specifically, regarding the contribution of CVD and T2D in reaching different levels of clinical disability in MS, 37.9% of patients reached EDSS 4.0, 24.9% reached EDSS 6.0, and 12.3% reached EDSS 7.0.

A multivariable model singled out the progression index (PI; HR=3.171; P<0.001), demonstrating that a higher PI served as an independent predictor of CVD in patients with MS, according to the study team. For T2D, PI (HR=6.052; P<0.001) and MS phenotype (HR=3.584; P<0.001) were statistically significant in univariable Cox regression analysis. These variables remained significant in multivariable analyses (HR=5.568 [P<0.001] and HR=2.339 [P=0.15], respectively), indicating that increased PI and the primary-progressive MS phenotype were independently tied to the incidence of T2D in people with MS.

The investigators acknowledged several limitations of their study, including the exclusion of smoking status, BMI, and vitamin D levels in the analyses. However, they also noted that data regarding these variables were lacking in the MS population registry used for the research.

The study team also pointed to directions for future research. Specifically, they suggested increasing the breadth of current investigations on the incidence of CVD comorbidities and T2D in MS through examination of the effect of adequate treatment and control of these comorbidities on slowing disability progression.