Study on French MS Population Reveals Long Disease Duration is Associated with Higher Mortality
A study recently published in the journal PLoS One revealed an excess mortality rate among French patients with multiple sclerosis (MS) that experience the disease for more than 20 years. The study was conducted by researchers at several institutes and hospitals in France, and is entitled “Excess Mortality in Patients with Multiple Sclerosis Starts at 20 Years from Clinical Onset: Data from a Large-Scale French Observational Study.”
MS is a chronic, progressive neurodegenerative disorder that results from an attack on the central nervous system (brain, spinal cord and optical nerves) by the body’s own immune system, causing inflammation and damage to the myelin layer that covers and protects neurons resulting in motor function impairment (coordination, balance, speech and vision), irreversible neurological disability and paralysis. MS mainly affects young adults, with the majority of the patients experiencing their first symptoms between 20 and 40 years of age. More than 2.3 million people in the world are estimated to suffer from MS, and there is currently no cure for the disease.
It was previously reported that MS patients have a reduced life expectancy in comparison to the general population. Researchers have now conducted a large-scale, observational, multicenter study (SURVIMUS) to analyze the specific mortality rate associated with MS in France. In total, 27,603 MS patients (mean age at onset of 33 years) were assessed in terms of life expectancy, mortality rates, causes of death, and prognostic factors in comparison to the French general population. All patients analyzed had clinical onset of the disease at least one year prior to the study.
The team found that 1,569 (5.7%) patients succumbed during the follow-up period of the study (mean 15.2 years), with half of the mortalities being related to MS. The mortality rate was found to be significantly higher among men, in patients with progressive MS (a form of the disease characterized by a gradual, steady progression of disability affecting at least 40% of all MS patients), and patients with later clinical onset. Researchers also observed that the excess mortality rates were moderate in comparison to the general population, although after 20 years of disease, excess mortality increased significantly among MS patients.
The research team concluded that in this French cohort, MS patients have a moderate decrease in life expectancy by approximately 7 years in comparison to the general population. In addition, the mortality rate was found to be strongly correlated to the patient’s disability and disease duration, with patients living with the disease for more than 20 years having an excess mortality rate. The team emphasized that an early intervention is required to slow disability progression and offer an extended life expectancy in MS patients.
While insights such as these may seem discouraging to the MS patient population, the findings from the SURVIMUS study are in fact helpful to researchers in focusing research efforts to develop next-generation MS therapies. Given that the study reveals that excess mortality occurs 20 years after disease onset, researchers underscore the need to slow down the progression of the disease. With novel experimental therapies focusing on neuroprotection and myelin regeneration, there are promising therapeutic approaches moving through the MS drug development pipeline that will further decrease MS progression, which in turn may lower mortality rates caused by the disease.