Smoking Cessation in Type 2 Diabetes – Weight Gain Impacts Outcomes

Does Quitting Smoking Help to Reduce Cardiovascular Risk in Type 2 Diabetes?

A recent study was published evaluating the effect of smoking cessation on cardiovascular disease incidence and mortality in type 2 diabetes.  This study analyzed the people with type 2 diabetes from the Nurses’ Health Study and the Health Professionals Follow-Up study.  They wanted to see the impact of the patient quitting smoking and cardiovascular outcomes.

Quick Summary of the Findings:

  • Compared to current smokers:
    • Cardiovascular disease
      • Recent Quitters (2-6 consecutive years of smoking cessation)
        • 17% lower risk in all recent quitters (HR 0.83; 95%CI 0.70-0.99)
        • Without weight gain  – 23% lower risk  (HR 0.77; 95%CI 0.62-0.95)
        • If gaining 0.1-5.0 kg – No reduction in risk (HR 0.99; 95%CI 0.70-1.41)
      • Long-term quitters (> 6 consecutive years of smoking cessation)
        • 28% lower risk in long-term quitters (HR 0.72; 95%CI 0.61-0.84)
    • Cardiovascular mortality
      • 31% lower all-cause mortality in long-term quitters (> 6 years) compared to smokers
      • Benefits of smoking cessation on all-cause mortality occurred even if the patient gained weight in the first 2-6 years after smoking cessation

What does this Mean for Practice?

  • Smoking significantly increases the cardiovascular disease risk and all-cause mortality in people with type 2 diabetes
  • If a patient can quit smoking for 2-6 years and does not gain weight
    • They have a lower risk of cardiovascular disease
  • If a patient quits for 2-6 years but gains weight
    • They don’t see the beneficial drop in cardiovascular disease risk
  • Long-term quitters (> 6 years)
    • Have a lower risk of cardiovascular, cancer and all-cause mortality regardless of any weight gain after quitting
  • Bottom Line – Smoking cessation can improve CV outcomes in patients with type 2 diabetes.  Minimizing weight gain when quitting (by counselling, using smoking cessation therapy and using therapies like GLP-1 RA’s or SGLT2i’s) can lead to a more positive effect on cardiovascular risk. 


Liu G, Hu Y, Zong G, et al. Smoking cessation and weight change in relation to cardiovascular disease incidence and mortality in people with type 2 diabetes: a population-based cohort study. The Lancet Diabetes & Endocrinology. January 2020:S2213858719304139. doi:10.1016/S2213-8587(19)30413-9