The preventable proportion of type 2 diabetes by ethnicity: the multiethnic cohort.

Purpose: To estimate the population-attributable risk (PAR) associated with modifiable risk factors for diabetes among Caucasians, Native Hawaiians, and Japanese Americans in the Hawaii component of the Multiethnic Cohort.

Methods: This analysis is based on 74,970 cohort participants ages 45-75 years who completed a questionnaire on demographics, diet, and lifestyle factors in 1993-1996. After a mean follow-up time of 12.1 (0.01-14.4) years, 8,559 diabetes cases were identified by self-report, a medication questionnaire, and through health plan linkages. Hazard ratios for diabetes and partial PARs for single and different combinations of modifiable risk factors were estimated.

Results: Overweight, physical inactivity, high meat intake, no alcohol consumption, and smoking were positively associated with diabetes risk in all ethnic groups. The estimated PARs suggested that among men, 78%, and among women, 83%, of new diabetes cases could have been avoided if all individuals had been in the low risk category for all of the modifiable risk factors. The slightly lower PARs in Japanese Americans were not significantly different from those in Caucasian and Native Hawaiian subjects.

Conclusions: Although PARs varied slightly over ethnicity, our findings do not support ethnic-specific prevention strategies; interventions targeted at multiple behaviors are needed in all ethnic groups.