Background and aimsThis study aimed to examine the association between dynamic smoking habit change and cardiovascular risk in a population newly diagnosed with hypertension, diabetes, and dyslipidemia.MethodsThis study included 49,320 individuals who had received health examinations provided by the Korea National Health Insurance Service. To determine the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident major adverse cardiac events (MACE) and all-cause mortality based on dynamic smoking habit changes for 2 years, multivariable Cox proportional hazard models were utilized.ResultsDuring the follow-up, there were 1,004 (2.2%), 3,483 (7.6%), and 334 (0.7%) cases of myocardial infarction, stroke events, and cardiovascular death, respectively. The group with worsening smoking habits had an increased risk of cardiovascular events and death (HR: 1.33, 95% CI: 1.26–1.40) compared to improved smoking habits. The robustness of the results determined by a series of sensitivity analyses further strengthened the main findings.ConclusionsOur findings suggest that worsening of smoking habits, even for a short period of time, may increase the risk of myocardial infarction, stroke, and cardiovascular death in patients diagnosed with hypertension, diabetes, and dyslipidemia. For the primary prevention of cardiovascular events in patients with underlying diseases, dynamic modification of smoking habits should be actively considered.