Trends in prevalence of diabetes mellitus and mean fasting glucose in Portugal (1987-2009): a systematic review.

OBJECTIVES: To assess time trends of the prevalence of diabetes and mean blood glucose in Portuguese adults. STUDY DESIGN: Systematic review. METHODS: The search strategy included Pubmed search and screening of bibliographic references of the review articles. Sex-specific linear regression models, with survey year and participants' age as independent variables, were used to predict prevalence estimates of self-reported diabetes and mean fasting glucose. RESULTS: Twenty-seven eligible studies were identified. Time trends of objectively defined diabetes could not be quantified due to the heterogeneity of the diagnostic criteria. Between 1987 and 2009, the prevalence of self-reported diabetes remained approximately constant in young adults, while it increased in middle-aged and older adults, more than two-fold among women and three-fold among men. In the same period, mean fasting glucose increased 7 mg/dL among women and 8 mg/dL among men. CONCLUSIONS: The prevalence of self-reported diabetes and mean fasting glucose increased in the last two decades, demanding for effective strategies to reverse this tendency and to manage the increasing number of people with diabetes in the Portuguese population.