OKLAHOMA CITY — While multiple sclerosis (MS) itself remains incurable, development of more effective treatments over the past 25 years has increased life expectancy for patients with the disease. Today, MS patients have a life expectancy only about seven years less than individuals without the disease, according to the National Multiple Sclerosis Society.
Still, most individuals with MS die not of the disease but of its complications or comorbidities. As a result, attention to preventive care may delay mortality, according to a study by researchers at the Oklahoma City VAMC. That might be particularly important for veterans.
More than 28,000 veterans currently receive MS care through the VA. “Veterans with MS have a number of features that are different from the civilian population,” according to Alicia Sloan, MPH, MSW, of the VA’s Multiple Sclerosis Center of Excellence-West in Seattle. “They also tend to be more disabled and more likely to have a progressive form of MS. This is in part because men tend to have more aggressive MS.”
The Oklahoma researchers sought to identify factors in MS mortality that are treatable and, as a result, improve care for veterans with the neurological disorder. For their study, published in the International Journal of MS Care, they conducted a retrospective review of 229 veterans registered in the MS program at the Oklahoma City VAMC between Jan. 1, 2000, and Dec. 31, 2014.1
The study team found that, while the disease itself contributed to the majority of deaths (57%) during the period, infection (43%), cancer (18%) and respiratory failure (18%) strongly influenced mortality, as well.
The researchers attributed the increase in infection and cancer rates indirectly to the disease modifying therapies that enabled patients to live longer, noting, “The availability of DMT increased the life expectancy of patients with MS, leading to an increase in age-related immune system change, which is less effective in dealing with micro-organisms and cancer cells, thus increasing their susceptibility to infections and cancer as causes of death.” The most common infections in the study were pneumonia and septicemia.
“Infection risk can be mitigated by annual vaccination against influenza and pneumonia and keeping a watch on their co-morbidities, in particular, diabetes,” explained lead author Meheroz H. Rabadi, MD, medical director, Oklahoma City VAMC Spinal Cord Injury and Disease, Multiple Sclerosis and ALS Program. The Oklahoma MS clinic aims to keep blood glucose levels (A1c) for diabetic veterans with MS at or below 6%, he added.
Diabetes poses a particular problem for MS patients throughout the course of the disease. “The presence of diabetes mellitus first delays MS diagnosis—as they share common sensory, motor and visual complaints—and second, it increases the risk of infection, which contributes to urinary and pneumonia-related deaths,” Rabadi pointed out.
The risk posed by infection can also be reduced by checking veterans’ complete blood counts for lymphocytes and leucocytes when they come in for their follow-up visits every four months, he told U.S. Medicine.
Reducing the risk of cancer poses more challenges. “As for the increased cancer risk, we have no mitigating approach other than surveillance on their follow-up visits. Since veterans with MS have often had the disease for 20 years or more and are now living longer, their risk is approaching that of the general population,” Rabadi said. In the study, skin, prostate and renal cancers occurred most frequently.
Previous studies had found that “vascular risk factors are the leading cause of both morbidity and mortality in the U.S. population. Patients with MS who have had one or more vascular risk factors had a more rapid disability progression” in a large study led by Canadian researcher Ruth Ann Marrie, MD, PhD, Rabadi said.2 Consequently, the Oklahoma program increased the focus on vascular risk factors for MS patients starting in 2007, which resulted in a reduction in cardiovascular-related deaths among clinic patients after 2008. The MS clinic closely monitors veterans’ hypertension, diabetes, hyperlipidemia and smoking during follow-up visits in addition to their MS care.
Overall, “appropriate treatment of both MS with disease modifying therapies (aiming for no evidence of disease activity or NEDA) and working with the veteran’s primary care provider to better control their comorbidities will help reduce their morbidity and mortality in the long run,” Rabadi said.
Over the 15 years of the study, mortality was 14%. Patients with progressive MS were far more likely to die: All 18 deaths among the 180 patients in the study from 2000 to 2009 were in patients who had progressive MS, as did 12 of the 15 patients who died in the 2010 to 2014 period.
Other factors associated with increased risk of death during the study included motor involvement, neurogenic bladder, pressure ulcers, greater disability, diabetes and lower body mass index. The standardized mortality rate in the study was 1.35 times greater than in the general Oklahoma population, a relatively modest increase in mortality compared to previous studies, which found standardized mortality rates approximately 2.5 times greater than their base population. The authors suggested that the lower rate to a “better access to medical care, better medical care … and access to rehabilitation services, resulting in veterans with MS having a near-normal life expectancy.”
- Rabadi MH, Aston CE. Predictors of Mortality in Veterans with Multiple Sclerosis in an Outpatient Clinic Setting. Int J MS Care. 2017 Sep-Oct;19(5):265-273. doi:10.7224/1537-2073.2016-067. PubMed PMID: 29070968; PubMed Central PMCID: PMC5649351.
- Marrie RA, Rudick R, Horwitz R, Cutter G, Tyry T, Campagnolo D, Vollmer T. Vascular comorbidity is associated with more rapid disability progression in multiple sclerosis. Neurology. 2010 Mar 30;74(13):1041-7. doi:10.1212/WNL.0b013e3181d6b125. PubMed PMID: 20350978; PubMed Central PMCID:PMC2848107.