Trends in diabetes prevalence. The Tromsø Study 1994-2016.

Introduction: The prevalence of type 2 diabetes is increasing worldwide. In Norway, register-based studies have reported an increased prevalence of type 2 diabetes and, recently, a decrease in incidence of type 2 diabetes. Aim: To investigate long-term trends in self-reported diabetes, HbA1c levels and medication use in a population-based study. Methods: We used self-report and laboratory data from adult women and men participating in one or more of four consecutive surveys of the population-based Tromsø Study; Tromsø 4 1994-95 (n=27158), Tromsø 5 2001 (n=8130), Tromsø 6 2007-08 (n=12984) and Tromsø 7 2015-16 (n=21083). Participants answered questionnaires including questions on diabetes and medication use. Non-fasting blood samples were collected and analysed for HbA1c at Department of Laboratory Medicine University Hospital North Norway. We included participants aged 40-89 years at each survey without missing values on the diabetes question in Tromsø 4 (n=16830), Tromsø 5 (n=7206), Tromsø 6 (n=12200), Tromsø 7 (n=20434) to study trends in diabetes prevalence. Moreover, we used HbA1c levels in Tromsø 4 (n=6720), Tromsø 5 (n=5833), Tromsø 6 (n=12003) and Tromsø 7 (n=20174) to study trends in diabetes unawareness (HbA1c =6.5% & no self-reported diabetes), and to study treatment target achievement (HbA1c=7.0% & self-reported diabetes). We used generalized estimating equation models to study overall and group-specific age-adjusted trends in women and men in 10-year age-groups. Results: In preliminary analyses, we found a statistically significant increase in prevalence of selfreported diabetes in both sexes and all age-groups. More results will be available. Conclusion: In these preliminary analyses, using self-report and laboratory data from repeated crosssectional surveys of an adult general population, we found an increase in prevalence of self-reported diabetes over the last two decades. [ABSTRACT FROM AUTHOR]