Multiple sclerosis is an autoimmune disease that destroys the fatty insulation of nerve cells, but many therapeutic techniques can improve quality of life for patients. Tettey and colleagues found that being overweight worsens multiple sclerosis symptoms and disability, and losing weight could slow down disease progression.
Multiple sclerosis (MS) is an autoimmune disease that results in degeneration of the central nervous system by eating away at myelin, the fatty insulation that covers nerve cells. This process is called demyelination and results in the breakdown of signal transmission among nerve cells. MS can lead to blindness, muscular weakness, and mental symptoms that include anxiety, depression, and cognitive impairment. MS can occur in a progressive fashion or as a series of isolated incidents over time.
Being able to predict the progression of MS is vital to designing treatments and therapies that reduce its negative effects and improve quality of life. Previous work has suggested that high blood lipid levels (including cholesterol and triglycerides) and body fat are potentially linked to a faster progression of MS. Understanding these links could help improve outcomes for individuals.
Tettey and colleagues published a study in the Journal of Neurology, Neurosurgery, and Psychiatry tracking the relationship of overweight and obesity to MS progression. The researchers specifically tracked blood lipid levels, BMI, and hip and waist circumference starting at the ‘first demyelinating event’—the first sign of MS. The total sample size was 279 individuals, including 190 individuals who were diagnosed with MS after a experiencing a second demyelinating event. These individuals were followed for five years, when they were also given a disability assessment using the Kurtzke Expanded Disability Status Scale. This scale was used to estimate the severity of their MS. BMI, blood lipid levels, and hip and waist circumferences were measured at the starting point, and at the 2-, 3-, and 5-year reviews. Tettey and colleagues then used a series of regression models to estimate the relationships of these variables to MS severity.
Tettey and colleagues found that among the group of 279 individuals, there was no evidence that blood lipid levels, BMI, or hip and waist circumference were linked to a second demyelinating event and the onset of MS. However, BMI was linked to a greater risk of additional demyelinating events—every 5 points of BMI increase were linked to a 25% risk increase. A similar link was found with hip circumference—for every 10cm increase in hip circumference there was a 29% risk increase. Higher blood triglyceride levels were also linked to a 22% risk increase, but cholesterol was not.
In addition, BMI at the time of the first demyelinating event was significantly linked to disability progression, so that individuals with higher BMI had faster increases in their disability scores. Similar links were found to blood cholesterol and triglyceride levels.
Together, these results show that being overweight does not increase the risk of getting MS, but being overweight worsens MS symptoms and disease progression. It may be that high blood lipid levels increase inflammation that is present in MS, resulting in faster nerve cell demyelination. Losing weight could slow down the onset of disability in MS patients. Future work will focus on the links between blood lipid levels, BMI, and hip and waist circumference and other symptoms of MS.
Written By: C.I. Villamil