title: Smoking, smoking cessation, and risk for type 2 diabetes mellitus: a cohort study.
abstract: BACKGROUND
  Cigarette smoking is an established predictor of incident type 2 diabetes mellitus, but the effects of smoking cessation on diabetes risk are unknown.
  
  
  OBJECTIVE
  To test the hypothesis that smoking cessation increases diabetes risk in the short term, possibly owing to cessation-related weight gain.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  The ARIC (Atherosclerosis Risk in Communities) Study.
  
  
  METHODS
  10,892 middle-aged adults who initially did not have diabetes in 1987 to 1989.
  
  
  METHODS
  Smoking was assessed by interview at baseline and at subsequent follow-up. Incident diabetes was ascertained by fasting glucose assays through 1998 and self-report of physician diagnosis or use of diabetes medications through 2004.
  
  
  RESULTS
  During 9 years of follow-up, 1254 adults developed type 2 diabetes. Compared with adults who never smoked, the adjusted hazard ratio of incident diabetes in the highest tertile of pack-years was 1.42 (95% CI, 1.20 to 1.67). In the first 3 years of follow-up, 380 adults quit smoking. After adjustment for age, race, sex, education, adiposity, physical activity, lipid levels, blood pressure, and ARIC Study center, compared with adults who never smoked, the hazard ratios of diabetes among former smokers, new quitters, and continuing smokers were 1.22 (CI, 0.99 to 1.50), 1.73 (CI, 1.19 to 2.53), and 1.31 (CI, 1.04 to 1.65), respectively. Further adjustment for weight change and leukocyte count attenuated these risks substantially. In an analysis of long-term risk after quitting, the highest risk occurred in the first 3 years (hazard ratio, 1.91 [CI, 1.19 to 3.05]), then gradually decreased to 0 at 12 years.
  
  
  CONCLUSIONS
  Residual confounding is possible even with meticulous adjustment for established diabetes risk factors.
  
  
  CONCLUSIONS
  Cigarette smoking predicts incident type 2 diabetes, but smoking cessation leads to higher short-term risk. For smokers at risk for diabetes, smoking cessation should be coupled with strategies for diabetes prevention and early detection.
authors.affiliation: Welch Center for Prevention, Epidemiology, and Clinical Research, The Johns Hopkins University, Baltimore, Maryland 21205, USA. hyeh1@jhmi.edu
authors.forename: Hsin-Chieh
authors.initials: HC
authors.lastname: Yeh
authors.forename: Bruce B
authors.initials: BB
authors.lastname: Duncan
authors.forename: Maria Inês
authors.initials: MI
authors.lastname: Schmidt
authors.forename: Nae-Yuh
authors.initials: NY
authors.lastname: Wang
authors.forename: Frederick L
authors.initials: FL
authors.lastname: Brancati
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000503:physiopathology; D016540:Smoking Cessation; D013997:Time Factors; D015430:Weight Gain