title: Coffee consumption and the incidence of type 2 diabetes in men and women with normal glucose tolerance: the Strong Heart Study.
abstract: OBJECTIVE
  It was reported that high coffee consumption was related to decreased diabetes risk. The aim of this study is to examine the association between coffee consumption and the incidence of type 2 diabetes in persons with normal glucose tolerance in a population with a high incidence and prevalence of diabetes.
  
  
  RESULTS
  In a prospective cohort study, information about daily coffee consumption was collected at the baseline examination (1989-1992) in a population-based sample of American Indian men and women 45-74 years of age. Participants with normal glucose tolerance (N = 1141) at the baseline examination were followed for an average of 7.6 years. The incidence of diabetes was compared across the categories of daily coffee consumption. The hazard ratios of diabetes related to coffee consumption were calculated using Cox proportional hazards models, adjusted for potential confounders. Levels of coffee consumption were positively related to levels of current smoking and inversely related to body mass index, waist circumference, female gender, and hypertension. Compared to those who did not drink coffee, participants who drank 12 or more cups of coffee daily had 67% less risk of developing diabetes during the follow-up (hazard ratio: 0.33, 95% confidence interval: 0.13, 0.81).
  
  
  CONCLUSIONS
  In this population, a high level of coffee consumption was associated with a reduced risk of deterioration of glucose metabolism over an average 7.6 years of follow-up. More work is needed to understand whether there is a plausible biological mechanism for this observation.
authors.affiliation: Center for American Indian Health Research, College of Public Health, University of Oklahoma Health Sciences Center, P.O. Box 26901, Oklahoma City, OK 73190, USA. Ying-zhang4@ouhsc.edu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: E T
authors.initials: ET
authors.lastname: Lee
authors.forename: L D
authors.initials: LD
authors.lastname: Cowan
authors.forename: R R
authors.initials: RR
authors.lastname: Fabsitz
authors.forename: B V
authors.initials: BV
authors.lastname: Howard
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000032:analysis*; D015992:Body Mass Index; D003069:Coffee; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006801:Humans; D006973:Hypertension / Q000473:pathology; D015994:Incidence; D007198:Indians, North American; D008019:Life Style; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking; D014481:United States; D055105:Waist Circumference
chemical_list: D001786:Blood Glucose; D003069:Coffee