Association of Duration of Smoking Cessation or Cumulative Smoking Amount with Serum hs-CRP Level in Korean Adults: A Nationwide Population-Based Cross-Sectional Study.

This study investigates the association between the duration of smoking cessation or cumulative smoking amount with serum high-sensitivity C-reactive protein (hs-CRP) levels. We assessed the decreasing risk for cardiovascular disease (CVD) and cancer following smoking cessation in Korean adults who were former smokers compared with current smokers. This study used data from the 2016−2018 Korea National Health and Nutrition Examination Survey. A total of 5411 participants were included. The duration of smoking cessation and cumulative smoking amount were classified into cut-offs for 6 and 17 months, and 5 and 20 pack-years, respectively, using tertile values. Elevated serum hs-CRP level was defined as ≥1 mg/L. Multivariate logistic regression analysis was performed. The odds ratio (OR) for elevated serum hs-CRP level was 0.73 times lower in the group whose duration of smoking cessation was 17 months or more than that in the group who were current smokers after adjusting for confounding variables (95% confidence interval (CI): 0.57−0.92; p < 0.01). The OR for elevated serum hs-CRP level was 0.71 and 0.67 times lower in the groups whose cumulative smoking amounts were less than 5 and 5−20 pack-years than that in the group who were current smokers (95% CI: 0.50−0.99 and 0.50−0.92, respectively; both p < 0.05). This study reveals that a duration of smoking cessation of more than 17 months and a cumulative smoking amount of less than 20 pack-years were significantly associated with a decreased risk of elevated serum hs-CRP levels in Korean adults who were former smokers. Therefore, quitting smoking early and a low cumulative smoking amount are a potential preventive strategy for CVD and cancer that can be easily accessible using serum hs-CRP.