Hypothetical midlife interventions in women and risk of type 2 diabetes

Epidemiology. 2013 Jan;24(1):122-8. doi: 10.1097/EDE.0b013e318276c98a.


Background: Randomized trials have examined short-term effects of lifestyle interventions for diabetes prevention only among high-risk individuals. Prospective studies have examined the associations between lifestyle factors and diabetes in healthy populations but have not characterized the intervention. We estimated the long-term effects of hypothetical lifestyle interventions on diabetes in a prospective study of healthy women, using the parametric g-formula.

Methods: Using data from the Nurses' Health Study, we followed 76,402 women from 1984 to 2008. We estimated the risk of type 2 diabetes under eight hypothetical interventions: quitting smoking, losing weight by 5% every 2 years if overweight/obese, exercising at least 30 minutes a day, eating less than three servings a week of red meat, eating at least two servings a day of whole grain, drinking two or more cups of coffee a day, drinking five or more grams of alcohol a day, and drinking less than one serving of soda a week.

Results: The 24-year risk of diabetes was 9.6% under no intervention and 4.3% when all interventions were imposed (55% lower risk [95% confidence interval = 47 to 63%]). The most effective interventions were weight loss (24% lower risk), physical activity (19%), and moderate alcohol use (19%). Overweight/obese women would benefit the most, with 10.8 percentage point reduction in 24-year risk of diabetes. The validity of these estimates relies on the absence of unmeasured confounding, measurement error, and model misspecification.

Conclusion: A combination of dietary and nondietary lifestyle modifications, begun in midlife or later in relatively healthy women, could have prevented at least half of the cases of type 2 diabetes in this cohort of U.S. women.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Diabetes Mellitus, Type 2 / etiology
  • Diabetes Mellitus, Type 2 / prevention & control*
  • Diet*
  • Exercise*
  • Female
  • Follow-Up Studies
  • Health Surveys
  • Humans
  • Kaplan-Meier Estimate
  • Life Style*
  • Middle Aged
  • Models, Statistical
  • Monte Carlo Method
  • Prospective Studies
  • Regression Analysis
  • Risk Factors
  • Smoking Cessation*
  • Surveys and Questionnaires
  • Weight Loss*