Smoking history and all-cause, ischaemic heart disease and lung cancer mortality: follow-up study of 358 551 men and women aged 40–43 years
Menée en Norvège par questionnaire auprès de 358 551 participants à un programme de dépistage des maladies cardiovasculaires (âge : 40-43 ans), cette étude prospective analyse l'association entre les pratiques tabagiques (nombre d'années de tabagisme, nombre de cigarettes consommées par jour), un sevrage tabagique avant l'âge de 43 ans et la mortalité par cancer du poumon
Aims: We studied the health consequences of quitting smoking before age 43 by time since quitting, number of years smoked and cigarettes smoked per day. The outcomes were all-cause, ischaemic heart disease and lung cancer mortality. Design: Prospective study. Setting: Norwegian counties. Participants: Men and women aged 40–43 years who participated in a national cardiovascular screening programme and who were followed from 1985 to 2018. Measurements: Self-reports from questionnaire on time since quitting smoking, years smoked and number of cigarettes per day, and measurements of height, weight and blood pressure, and a blood sample where serum was analysed for total serum cholesterol and triglycerides. Findings: The all-cause mortality rate was 30% higher among quitters less than 1 year ago compared with never smokers (adjusted HR=1.30, 95% CI 1.18–1.43 in men and HR=1.31, 95% CI 1.16 to 1.50 in women). Quitters who had smoked longer than 20 years had 23% higher mortality in men (HR=1.23, 95% CI 1.14 to 1.34) and 32% higher mortality in women (HR=1.32, 95% CI 1.18 to 1.49). Past smoking of more than 20 cigarettes/day was associated with HR=1.14 (1.05–1.23) in men and HR=1.16 (1.01–1.32) in women. The HR for lung cancer was 6.77 (95% CI 4.86 to 9.45) for quitting men who had smoked for more than 20 years compared with never smokers. The corresponding figure for women was 5.75 (95% CI 4.08 to 8.09). Conclusions :The mortality among quitters was close to that of never smokers, except for a higher mortality for lung cancer, which on the other hand was much lower than the lung cancer mortality in current smokers.