title: Association of cigarette smoking with diabetic retinopathy.
abstract: OBJECTIVE
  To determine whether cigarette smoking is associated with the incidence and progression of diabetic retinopathy.
  
  
  METHODS
  Younger-onset diabetic subjects who had been diagnosed at less than 30 yr of age and taking insulin (n = 1210) and a random sample of older-onset diabetic subjects diagnosed at greater than or equal to 30 yr of age (n = 1780) were selected. Baseline examinations were conducted on 996 younger- and 1370 older-onset subjects. Incidence of retinopathy was based on 138 younger-onset and 154 older-onset insulin-taking subjects and 321 older-onset non-insulin-taking subjects who were free of retinopathy at baseline. Progression of retinopathy was based on 530 younger-onset and 418 older-onset insulin-taking subjects and 486 older-onset non-insulin-taking subjects with less than proliferative diabetic retinopathy at baseline.
  
  
  RESULTS
  Baseline smoking history was categorized by status (nonsmoker, ex-smoker, current smoker) and pack-years smoked while diabetic. Retinopathy was documented by stereoscopic fundus photography. In univariate analyses, the only significant association was between pack-years and progression to proliferative diabetic retinopathy in older-onset insulin-taking subjects (P less than 0.01). After controlling for known risk factors for the incidence and progression of retinopathy, pack-years smoked was borderline significant (P = 0.052) in predicting incidence of retinopathy in younger-onset subjects. Smoking was not associated with incidence in older-onset subjects or with progression or progression to proliferative diabetic retinopathy in any of the groups.
  
  
  CONCLUSIONS
  Smoking is not likely to be an important risk factor for diabetic retinopathy.
authors.affiliation: Department of Ophthalmology, University of Wisconsin Medical School, Madison.
authors.forename: S E
authors.initials: SE
authors.lastname: Moss
authors.forename: R
authors.initials: R
authors.lastname: Klein
authors.forename: B E
authors.initials: BE
authors.lastname: Klein
mesh_terms: D000328:Adult; D000367:Age Factors; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D011897:Random Allocation; D012907:Smoking / Q000009:adverse effects*