Long COVID and smoking: magnitude of the problem in an outpatient respiratory unit
More details
Hide details
Servicio de Neumología, Hospital Universitario de La Princesa, Madrid, Spain
Institut Català d’Oncologia, Barcelona, Spain
Joan B. Soriano   

Servicio de Neumología, Hospital Universitario de La Princesa, Madrid, Spain
Publication date: 2023-04-25
Tob. Prev. Cessation 2023;9(Supplement):A130
Up to 16% of patients continue to have symptoms one year after overcoming acute COVID-19. It is estimated there are 400,000 to 800,000 Long COVID patients in Spain. Although the relationship between COVID-19 and smoking was initially highly controversial, the evidence that smoking is a risk factor for infection, increased severity, and mortality in COVID-19 is now overwhelming. However, the role of current- and former-smoking in patients with Long COVID is unknown. Our main objective is to determine the prevalence of current- and former smokers, and the effect of associated variables, in patients with Long COVID.

Material and Methods:
Cross-sectional study of patients with Long COVID enrolled for a prospective follow-up. All were identified in the post-COVID Outpatient Consultation of the Respiratory Department of Hospital de La Princesa, in Madrid, Spain. Smoking status was assessed via standardised questionnaires. Socio-demographic variables, comorbidities, and laboratory biomarkers at baseline, plus treatments and COVID-related use of health services, were also assessed.

Out of 473 patients with Long COVID, 28 (5.9%) were active smokers and 121 (25.6%) were ex-smokers. Compared with never-smokers, Long COVID patients who were current-smokers were younger (62.2 y) and more frequently male (64.3%) (both p<0.001), but with no significant differences in body mass index. Current-smokers had more COPD (32.1%), malnourishment (14.3%), rheumatism (7.1%), and solid tumours (7.1%) compared to never-smokers (all p<0.05); they also had higher D-dimer 4.9±15.6 (p=0.012), and C-Reactive Protein 15.4±9.1 (p=0.005), and a variable use of health services during hospitalization, but with no differences in drugs received.

Smoking is frequent in Long COVID patients, 5.9% active smokers and 25.6% ex-smokers in our series, and it is associated with largely negative consequences in the acute and long-term care of these patients.