Study shows increased risk of diabetes after smoking cessation lasts for 12 years

Yeh HC, Duncan BB, Schmidt MI, Wang NY, Brancati FL. Smoking, smoking cessation, and risk for type 2 diabetes mellitus: a cohort study. Ann Intern Med. 2010 Jan 5;152(1):10-7. doi: 10.7326/0003-4819-152-1-201001050-00005. PMID: 20048267; PMCID: PMC5726255.

Smoking cessation treatment is associated with increased incidence of diabetes and chronic obstructive pulmonary disease (in males) within

Baliunas D, Voci S, Selby P, de Oliveira C, Kurdyak P, Rosella L, Zawertailo L, Fu L, Sutradhar R. Incidence of chronic disease following smoking cessation treatment: A matched cohort study using linked administrative healthcare data in Ontario, Canada. PLoS One. 2023 Jul 26;18(7):e0288759. doi: 10.1371/journal.pone.0288759. PMID: 37494345; PMCID: PMC10370896.

Men who gave up smoking during the first 5 years of follow-up showed significant weight gain and subsequently higher risk of diabetes than continuing smokers. The benefit of giving up smoking was only apparent after 5 years of smoking cessation, and risk reverted to that of never-smokers only after 20 years. 

Wannamethee SG, Shaper AG, Perry IJ; British Regional Heart Study. Smoking as a modifiable risk factor for type 2 diabetes in middle-aged men. Diabetes Care. 2001 Sep;24(9):1590-5. doi: 10.2337/diacare.24.9.1590. PMID: 11522704.

Heavy smoking moderately increases the risk for DM in obese men. But, light smoking reduces the risk in lean men.

Nagaya T, Yoshida H, Takahashi H, Kawai M. Heavy smoking raises risk for type 2 diabetes mellitus in obese men; but, light smoking reduces the risk in lean men: a follow-up study in Japan. Ann Epidemiol. 2008 Feb;18(2):113-8. doi: 10.1016/j.annepidem.2007.07.107. PMID: 18083537.

Among former smokers, the risk of diabetes decreased significantly as the time since quitting increased and was equal to that of never smokers following a cessation period of 10 years. 

Luo, Juhua et al. “Smoking and diabetes: does the increased risk ever go away?.” American journal of epidemiology vol. 178,6 (2013): 937-45. doi:10.1093/aje/kwt071