By Robert Preidt
TUESDAY, Sept. 8, 2015 (HealthDay News) -- Multiple sclerosis progresses faster in people who continue to smoke compared to smokers who quit after their diagnosis, a new study finds.
"This study demonstrates that smoking after MS diagnosis has a negative impact on the progression of the disease, whereas reduced smoking may improve patient quality of life, with more years before [progression to secondary disease]," wrote Dr. Jan Hillert, of the Karolinska Institute in Sweden, and colleagues.
"Evidence clearly supports advising patients with MS who smoke to quit. Health care services for patients with MS should be organized to support such a lifestyle change," the study authors concluded in the report published online Sept. 8 in the journal JAMA Neurology.
Multiple sclerosis is a disease of the nervous system that affects your brain and spinal cord. Symptoms can include vision problems, muscle weakness, coordination and balance trouble, and thinking and memory problems.
Smoking is a known risk factor for MS, the study authors said. MS begins with irregular and worsening relapses, but usually changes after about 20 years into what is called secondary progressive (SP) disease. The time from disease onset to secondary progressive disease is a widely used measure of MS progression, the authors explained in a journal news release.
The study included more than 700 MS patients in Sweden who were smokers at the time of their diagnosis. Some patients continued smoking while others quit within a year, the researchers said.
Each additional year of smoking after MS diagnosis accelerated the time to secondary progressive disease by nearly 5 percent, the findings showed. People who continued to smoke each year after diagnosis converted to secondary progressive disease earlier (average age 48) than those who quit smoking (average age 56), the research revealed.
The study adds to evidence that smoking is a major modifiable risk factor for MS, Dr. Myla Goldman, of the University of Virginia in Charlottesville, and Dr. Olaf Stuve, of the University of Texas Southwestern Medical Center at Dallas, wrote in an accompanying editorial.
"Most importantly, it provides the first evidence, to our knowledge, that quitting smoking appears to delay onset of secondary progressive MS and provide protective benefit. Therefore, even after MS diagnosis, smoking is a risk factor worth modifying," Goldman and Stuve wrote.