title: Stress increases the risk of type 2 diabetes onset in women: A 12-year longitudinal study using causal modelling.
abstract: BACKGROUND
  Type 2 diabetes is associated with significant morbidity and mortality. Modifiable risk factors have been found to contribute up to 60% of type 2 diabetes risk. However, type 2 diabetes continues to rise despite implementation of interventions based on traditional risk factors. There is a clear need to identify additional risk factors for chronic disease prevention. The aim of this study was to examine the relationship between perceived stress and type 2 diabetes onset, and partition the estimates into direct and indirect effects.
  
  
  RESULTS
  Women born in 1946-1951 (n = 12,844) completed surveys for the Australian Longitudinal Study on Women's Health in 1998, 2001, 2004, 2007 and 2010. The total causal effect was estimated using logistic regression and marginal structural modelling. Controlled direct effects were estimated through conditioning in the regression model. A graded association was found between perceived stress and all mediators in the multivariate time lag analyses. A significant association was found between hypertension, as well as physical activity and body mass index, and diabetes, but not smoking or diet quality. Moderate/high stress levels were associated with a 2.3-fold increase in the odds of diabetes three years later, for the total estimated effect. Results were only slightly attenuated when the direct and indirect effects of perceived stress on diabetes were partitioned, with the mediators only explaining 10-20% of the excess variation in diabetes.
  
  
  CONCLUSIONS
  Perceived stress is a strong risk factor for type 2 diabetes. The majority of the effect estimate of stress on diabetes risk is not mediated by the traditional risk factors of hypertension, physical activity, smoking, diet quality, and body mass index. This gives a new pathway for diabetes prevention trials and clinical practice.
authors.affiliation: Research Centre for Generational Health and Ageing, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Melissa L
authors.identifier: http://orcid.org/0000-0002-5733-9684
authors.initials: ML
authors.lastname: Harris
authors.affiliation: Clinical Research Design, IT and Statistical Support Unit, Hunter Medical Research Institute, Newcastle, New South Wales, Australia.|School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Oldmeadow
authors.affiliation: Research Centre for Generational Health and Ageing, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.|School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Alexis
authors.initials: A
authors.lastname: Hure
authors.affiliation: School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.|Division of Medicine, John Hunter Hospital, Hunter New England Health, Newcastle, New South Wales, Australia.
authors.forename: Judy
authors.initials: J
authors.lastname: Luu
authors.affiliation: Research Centre for Generational Health and Ageing, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.
authors.forename: Deborah
authors.initials: D
authors.lastname: Loxton
authors.affiliation: Clinical Research Design, IT and Statistical Support Unit, Hunter Medical Research Institute, Newcastle, New South Wales, Australia.|School of Medicine and Public Health, Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia.|Division of Medicine, John Hunter Hospital, Hunter New England Health, Newcastle, New South Wales, Australia.
authors.forename: John
authors.identifier: http://orcid.org/0000-0001-9800-1308
authors.initials: J
authors.lastname: Attia
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology*; D015444:Exercise; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008137:Longitudinal Studies; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D012307:Risk Factors; D013315:Stress, Psychological / Q000150:complications*