Many of you will have registered themselves on the UK MS registry. This is an online registry that aims to monitor the motor, mood and treatment status of pwMS based on what we call patient-reported outcomes or PRO’s. This means that pwMS voluntarily fill out simplified MS questionnaires every 6 months after being prompted by MS email spam of the most honourable kind. Based on the responses of thousands of pwMS, UK researchers have looked into the association of current, former or never smoking and MS disease course.
The UK MS register verdict:
1. Smoking is associated with worsening of motor function and walking range compared to non-smokers. Importantly, a direct relationship between smoking and the worsening of PRO’s is hinted by the fact that heavy smokers (for all the people still in denial: > 13 cigarettes per day) experience an accelerated rate of worsening compared to light smokers (<7 cigarettes). Moreover, there was a deceleration in the rate of motor deterioration following smoking cessation and the disease course became similar to pwMS who had never smoked. One of the reasons to explain these associations might be that nicotine activates white blood cells and leads to increased inflammation throughout the body. This theory also explains why smoking is not only linked to MS as an autoimmune disease, but also to rheumatoid arthritis, lupus erythematous, thyroid disease, …
2. Although anxiety levels did not increase in pwMS experiencing worsening motor function, anxiety was consistently higher in current smokers and improved with smoking cessation. This implies that for at least a number of smokers it would be very valuable to be referred for psychological support as part of a smoking cessation strategy in which cigarettes are replaced by other coping strategies.
3. The frequency of smoking among pwMS is unfortunately on par with the national UK average. These numbers emphasise neurologists need to invest time in increasing awareness about the negative effects of smoking on the MS disease course. The first step would be to systematically query about smoking status in clinics and to set up collaborations with smoking cessation clinics.
As smoking is undeniably a form of addiction, I am well aware that rational arguments (read: evidence from a large UK MS registry, stroke risk, cancer risk, costs) are unlikely to make a difference to pwMS currently still smoking. Moreover, it is confronting to realise that smoking habits are not equally distributed among pwMS, and that people from non-white ethnic background who are already more vulnerable socio-economically are also more likely to smoke. Nonetheless, it would be a good idea to put more weight on lifestyle measures such as smoking cessation in MS guidelines. As any indoor smoker would reasonably say: let’s open the window!
Were you aware of the association? Do you consider to stop smoking? What kind of information would make a difference for you? Please share your thoughts!
Disclaimer: Please note that the opinions expressed here are those of dr. Ide Smets and do not necessarily reflect the position of the Barts and The London School of Medicine and Dentistry nor Barts Health NHS Trust.
Jeff Rodgers 1, Tim Friede 2, Frederick W Vonberg 3, Cris S Constantinescu 4, Alasdair Coles 5, Jeremy Chataway 6 7, Martin Duddy 8, Hedley Emsley 9 10, Helen Ford 11, Lennora Fisniku 12, Ian Galea 13, Timothy Harrower 14, Jeremy Hobart 15, Huseyin Huseyin 16, Christopher M Kipps 13, Monica Marta 17 18, Gavin V McDonnell 19, Brendan McLean 20, Owen R Pearson 21, David Rog 22, Klaus Schmierer 18 23, Basil Sharrack 24, Agne Straukiene 25, Heather C Wilson 26, David V Ford 1, Rod M Middleton 1, Richard Nicholas 1 3 27, MS Register groupAffiliations expand
- PMID: 34623418
- DOI: 10.1093/brain/awab385
The negative impact of smoking in MS is well established, however, there is much less evidence as to whether smoking cessation is beneficial to progression in MS. Adults with MS registered on the United Kingdom MS Register (2011-2020) formed this retrospective and prospective cohort study. Primary outcomes were changes in 3 patient reported outcomes (PROs): normalised MS Physical Impact Scale (MSIS-29-Phys), normalised MS Walking Scale (MSWS-12) and the Hospital Anxiety and Depression Scale (HADS-Anxiety and HADS-Depression). Time to event outcomes were clinically significant increases in the PROs. 7983 participants were included, 4130 (51.7%) of these had ever smoked; of whom 1315 (16.5%) were current smokers and 2815/4130 (68.2%) were former smokers. For all PROs, current smokers at the time of completing their first questionnaire had higher PRO scores indicating higher disability compared to those who had never smoked (∼10 points difference in MSIS-29-Phys and MSWS-12; 1.5-1.8 point for HADS-anxiety and HADS-depression). There was no improvement in PRO scores with increasing time since quitting in former smokers. 923 participants formed the prospective parallel group, which demonstrated that MSIS-29-phy 5.03, [3.71, 6.34], MSWS-12 5.28, [3.62, 6.94] and HADS-depression 0.71, [0.47, 0.96] worsened over a period of 4 years, whereas HADS-anxiety remained stable. Smoking status was significant at year 4; current smokers had higher MSIS-29-Phys and HADS-Anxiety scores (3.05 [0.22, 5.88], 1.14 [0.52,1.76]) while former smokers had a lower MSIS-29 score of -2.91[-5.03, -0.79]. 4642 participants comprised the time to event analysis. Still smoking was associated with a shorter time to worsening event in all PROs (MSIS-29-Phys: n = 4436, p = 0.0013; MSWS-12: n = 3902, p = 0.0061; HADS-anxiety: n = 4511, p = 0.0017; HADS-depression: n = 4511, p < 0.0001). Worsening in motor disability (MSIS-29-Phys and MSWS-12) was independent of baseline HADS-anxiety and HADS-depression scores. There was no statistically significant difference in the rate of worsening between never and former smokers. When smokers quit, there is a slowing in the rate of motor disability deterioration so that it matches the rate of motor decline in those who have never smoked. This suggests that smoking cessation is beneficial for people with MS.