Association between cumulative pack-year smoking exposure and sarcopenia: a KoGES cohort study.

Background: Sarcopenia is the age-related involuntary loss of skeletal muscle mass and strength. Many factors, such as ageing and behaviour, may affect the risk of sarcopenia. However, no study had confirmed the association between cumulative exposure to smoking and the risk of developing sarcopenia. Therefore, in this study we investigated the association between cumulative smoking exposure and the risk of sarcopenia.

Methods: After excluding some invalid data, 8818 participants aged 40-69 years were included in the Korean Genomics and Epidemiology Study (KoGES) cohort, spanning 16 years (2001-2016). Sarcopenia was diagnosed based on biennial measurements of the appendicular lean mass index using bioelectrical impedance analysis following the Asian Working Group for Sarcopenia (AWGS) criteria. Smoking status and cumulative smoking exposure were self-reported at baseline. Cox proportional hazards regression analysis was conducted to assess sarcopenia occurrence based on smoking status and cumulative smoking amount after adjusting for age, sex, medical history, marital status, alcohol consumption and smoking habits, protein intake, and physical activity.

Results: The study induced 8818 participants with an average age of 51.9 years; 44.5% were men, and the mean follow-up duration was 8.4 years. After adjusting for covariates, smokers exhibited a higher risk of sarcopenia than non-smokers, with a hazard ratio of 1.279 (95% confidence interval: 1.064-1.657). Moreover, there was a dose-response relationship between cumulative smoking exposure and sarcopenia risk, with hazard ratios increasing with higher pack-year values relative to non-smokers.

Conclusion: Cumulative smoking exposure, measured in pack-years, was associated with increased sarcopenia incidence in a Korean cohort.