Survival
in MS has increased during the era of disease modifying therapies, but
life expectancy in MS patients is still reduced by several years.
Increased risk for common comorbidities related to brain health, such as
risk for circulatory diseases have been reported in MS and could affect
survival. In this paper, we studied age- and gender adjusted risks for
circulatory diseases and related disorders, and their impact on overall
MS survival in population of Southwest Finland.

The
ICD-10 codes for hospital visits were searched from the administrative
data pool from 1.1.2004 up to 31.12.2012 for the resident MS and control
cases at the Hospital District of Southwest Finland. The MS population
under study consisted of prevalent cases in 1.1.2004 and new cases from
1.1.2004 followed up to death or 31.12.2012. Patient documents were
scrutinized to confirm the MS diagnosis (G 35) by the McDonald´s
criteria and to confirm the diagnoses and causes of death for the
cerebro- and cardiovascular diagnoses under study. The randomly chosen
10-fold control population was matched by birth year and gender to
calculate the coincident risks (odds ratio, OR) with 95% confidence
intervals (95% CI) and another separate control population from the same
patient pool was used to verify the stability of the results. P-values
were calculated using Pearson's χ2 test. The Kaplan- Meier analysis log
rank test was applied to study survival.

During
the follow-up 1074 confirmed MS cases were treated in the hospital
district, including the deceased cases after 1.1.2004 (5.9%). The
probability of survival was 82.4 years among MS and 85.6 years among the
control cases, log rank p < 0.001. The survival disadvantage within
MS was associated with comorbidity for circulatory disease codes in ICD
-10: I06-I71, log rank p < 0.001. The specific risk for ischemic and
haemorrhagic stroke was significant with high OR of 1.49 (95% CI 1.03-
2.35) and 2.5 (1.24-5.06) respectively. The two-fold risk for type 1
diabetes in MS was significant, OR 2.1 (1.3-3.36). The main causes of
death among the MS cases were infections and the coincident high risk
for several infections was significant. There was no difference in the
risk for acute myocardial infarct, transient ischemic attack, atrial
fibrillation, hypertension, or obesity in comparison with the control
cases.

Given
the high risk for stroke in this MS population and the observed
complexity among the coincident common risk factors for circulatory
diseases, the high risk for type 1 diabetes and common infections raise a
need to recognize patients at risk with these conditions and with the
other known risk factors such as metabolic syndrome and smoking. The
survival disadvantage related to circulatory diseases observed in
general population is true also in MS and should be recognized to reduce
the burden of disease and premature mortality in MS.