A new study entitled “Effect of Smoking Cessation on Multiple Sclerosis Prognosis” recently revealed that smoking by patients with multiple sclerosis (MS) post diagnosis accelerates their disease progression course. The study was published in the journal JAMA Neurology and was led by researchers at the Karolinska Institutet in Sweden.
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, resulting in motor function, irreversible neurological disability and paralysis. It is estimated that more than 2.3 million people in the world suffer from the disease.
Progressive MS is estimated to affect at least 40% of all MS patients. It is characterized by a gradual, steady progression of disability, leading to impaired vision and walking, pain, fatigue and cognitive changes. Progressive MS can be either primary, where patients develop this form of the disease from the time of diagnosis, or secondary, where patients initially experience a relapsing-remitting phase of neurological dysfunction that later evolves into a secondary progressive disease. Primary progressive MS only affects 10 to 15% of the MS patients, while the majority (85%) develops secondary progressive MS (SPMS).
One well-established risk factor for developing MS is smoking tobacco; however, it is not clear if smoking after the disease diagnosis is detrimental.
In order to address this question and assess whether smoking after an MS diagnosis alters the time of disease progression to SPMS, researchers conducted a study with a cohort of 728 MS Swedish patients who were smokers and participated in the Genes and Environment in Multiple Sclerosis Study, part of the Swedish National MS Registry. Data was collected between November 2008 and December 2011 through questionnaires. After the diagnosis, 332 MS patients out of the 728 continued to smoke.
Researchers found that each additional year of smoking after an MS diagnosis accelerated the time needed for the disease to progress into SPMS by 4.7%. In the cohort analyzed, MS patients who continued to smoke after their diagnosis developed SPMS faster (at 48 years of age) in comparison to MS patients who quit smoking (56 years of age).
In conclusion, the research team showed, for the first time, that MS patients who continue to smoke after their diagnosis are at an increased risk of progressing faster to SPMS. The authors suggest that patients diagnosed with MS should be advised to stop smoking in order to reduce the risk of comorbidities and also to avoid aggravating MS-related disability. The team also proposes that healthcare services should support such lifestyle change for MS patients.