title: Smoking and the Risk of LADA: Results From a Swedish Population-Based Case-Control Study.
abstract: Smoking is an established risk factor for type 2 diabetes. In contrast, it has been proposed that smoking may reduce the risk of latent autoimmune diabetes in adults (LADA), but studies are scarce. We aimed to study the impact of smoking on LADA and type 2 diabetes risks.
  
  
  
  We used data from a Swedish case-control study including incident case patients with LADA (GAD antibody [GADA] positive, n = 377) and type 2 diabetes (GADA negative, n = 1,188) and control subjects randomly selected from the population (n = 1,472). We calculated odds ratios (ORs) with 95% CIs by logistic regression, adjusted for age, sex, BMI, family history of diabetes, and alcohol consumption.
  
  
  
  There was no indication of reduced risk of LADA in smokers; instead, heavy smoking was associated with an increased risk of LADA (OR 1.37, 95% CI 1.02-1.84). Heavy smokers had higher levels of HOMA of insulin resistance (9.89 vs. 4.38, P = 0.0479) and HOMA of β-cell function (55.7 vs. 42.5, P = 0.0204), but lower levels of GADA (75 vs. 250, P = 0.0445), compared with never smokers. Smokers also displayed an increased risk of type 2 diabetes (OR in ever smokers 1.53, 95% CI 1.25-1.88).
  
  
  
  In this large population of LADA patients, we did not observe a protective effect of smoking on autoimmunity and the risk of LADA. A protective effect could possibly be masked by a smoking-induced aggravation of insulin resistance, akin to the diabetogenic effect seen in individuals with type 2 diabetes.
authors.affiliation: Epidemiology Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden bahareh.rasouli@ki.se.
authors.forename: Bahareh
authors.initials: B
authors.lastname: Rasouli
authors.affiliation: Epidemiology Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden Center for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Andersson
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Per-Ola
authors.initials: PO
authors.lastname: Carlsson
authors.affiliation: NTNU Institute of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway Department of Endocrinology, Trondheim University Hospital, Trondheim, Norway.
authors.forename: Valdemar
authors.initials: V
authors.lastname: Grill
authors.affiliation: Department of Clinical Sciences in Malmö, Clinical Research Centre, Lund University, Malmö, Sweden.
authors.forename: Leif
authors.initials: L
authors.lastname: Groop
authors.affiliation: Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Martinell
authors.affiliation: Department of Clinical Sciences in Malmö, Clinical Research Centre, Lund University, Malmö, Sweden.
authors.forename: Petter
authors.initials: P
authors.lastname: Storm
authors.affiliation: Division of Endocrinology, Helsinki University Hospital; Finnish Institute for Molecular Medicine and Research Program for Diabetes and obesity, University of Helsinki; and Folkhalsan Research Center, Helsinki, Finland.
authors.forename: Tiinamaija
authors.initials: T
authors.lastname: Tuomi
authors.affiliation: Epidemiology Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Sofia
authors.initials: S
authors.lastname: Carlsson
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology / Q000276:immunology; D015551:Autoimmunity / Q000502:physiology; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology; D005260:Female; D006801:Humans; D000071698:Latent Autoimmune Diabetes in Adults / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology* / Q000276:immunology; D013548:Sweden / Q000453:epidemiology