ASSOCIATION BETWEEN PASSIVE AND ACTIVE SMOKING AND RISK OF HIP FRACTURE: DATA FROM THE FRENCH E3N COHORT

Background: Active smoking is a risk factor for osteoporosis and osteoporotic fractures. Passive smoking has been shown to have a deleterious effect on bone in mouse models. Objectives: The aim was to assess the association between active and/or passive smoking and the risk of hip fracture in postmenopausal women in a large French prospective cohort. Methods: The E3N study (Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale) is a prospective French cohort of women included in 1990 and followed prospectively by self-reported questionnaires sent out every 2 to 3 years until 2018 (date of the 12th questionnaire). Exposures to passive and active smoking were assessed using self-reported questionnaires. Fractures were collected prospectively from the follow-up questionnaires. Cox proportional hazards regression models adjusted for age and for potential confounders were used to estimate HRs and 95% CIs for incident hip fracture. Results: Among the 94,389 women, the mean age at inclusion was 50.5 years (3.9), 53.6% were non-smokers or had never smoked, 14.7% were active smokers and 58.7% had been exposed to passive smoking (child + adult). A history of pre-menopausal fracture was found in 16.9% of the women. The mean duration of follow-up was 20.6 years (6.9). During follow-up, 2339 women had a postmenopausal hip fracture (mean age 71.8 years (9.52)). Active smoking was associated with an increased risk of hip fracture (HR 1.20; 95% CI 1.02-1.41) after adjustment for age and confounding factors (active and passive smoking, BMI, level of education, diabetes, history of cancer and fracture, history of rheumatoid arthritis, early menopause and menopausal hormone therapy). Passive smoking in childhood and adulthood was not associated with an increased risk of hip fracture (HR 1.09 95% CI (0.96-1.23) and 1.02 95% CI (0.93-1.11) respectively). Others factors associated with an increased risk of hip fracture were low BMI (< 18.5 kg/m2) (HR 1.54; 95% CI 1.28-1.89), a history of rheumatoid arthritis (HR 1.58; 95% CI 1.12-2.22) and a history of fracture (all types) before the menopause (HR 1.46; 95% CI 1.31-1.61). Early menopause was not associated with an increased risk of hip fracture. Hormonal treatment of the menopause was associated with a reduced risk of hip fracture (HR 0.91 95% CI 0.83-0.99). Conclusion: Active smoking in adulthood is associated with an increased risk of postmenopausal hip fracture. Passive smoking in childhood and adulthood was not significantly associated with an increased risk of postmenopausal hip fracture. A history of pre-menopausal fracture (mainly non-osteoporotic) was associated with a significant increased risk of fracture. Hormonal treatment of the menopause was associated with a reduced risk of hip fracture. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared. DOI: 10.1136/annrheumdis-2024-eular.4366 Keywords: Epidemiology, Bone Citation: , volume 83, supplement 1, year 2024, page 145Session: Clinical Abstract Sessions: Risk factors and treatment in osteoporosis (Oral Abstract Presentations)

Epidemiology, Bone