SummaryDiabetes type 2 (T2D) is assumed to have a multifactorial pathogenesis, including genetic dispositions, adiposity, physical inactivity and environmental factors. However, while abundant evidence supports the first three factors, limited evidence is available on the potential effects of environmental factors particularly availability of green spaces in the residential area on T2D incidence risk. Furthermore, although green spaces have been associated with increased physical activity and reduced body mass index (BMI), there is scant evidence supporting the role of these two factors as mediators in the association between green spaces and T2D risk. Using longitudinal data from the German National Cohort (NAKO), we therefore aim to assess whether green spaces near residential areas influence the risk of developing T2D and whether this relationship is mediated by increased physical activity and BMI. For exposure assessment. we will use geocoded data on greenness which is linked to NAKO participants’ residences by the Environmental data unit. During follow-up, the occurrence of T2D will be determined by self-reports of the study participants as well as increased HbA1c levels in blood analyses. To estimate the probability of developing T2D in relation to greenspace exposure and to assess the potential mediating role of BMI and physical activity, Cox proportional hazards models and causal mediation analyses will be used, respectively. A sensitivity analysis will be performed to validate our classification of type 2 diabetes using diagnosis codes recorded in insurance claims data.

Keywords diabetes-mellitus environment exposome greenness lifestyle

InstitutionsLeibniz-Institut für Präventionsforschung und Epidemiologie - BIPS GmbH, Leibniz-Institut für Präventionsforschung und Epidemiologie - BIPS, Leibniz Institute for Prevention Research and Epidemiology - BIPS