Geospatial analysis of sodium and potassium intake: a Swiss population-based study

David De Ridder, Fabiën N. Belle,Pedro Marques-Vidal, Belén Ponte,Murielle Bochud, Silvia Stringhini, Stéphane Joost, and Idris Guessous.
Geospatial Analysis of Sodium and Potassium Intake: A Swiss Population-Based StudyNutrients, May 2021, doi: 108.3390/nu1306179

Abstract

Background: Inadequate dietary intakes of sodium and potassium are associated with major preventable health consequences. Local public health interventions can be facilitated and informed by fine-scale geospatial analyses.

Method: In this study, we evaluate the existence of spatial groupings, or clusters (i.e. an unusual concentration of individuals with a specific outcome in space) of estimated intakes of sodium (Na), potassium (K), and the Na:K ratio in the annual population surveys of the Bus Santé study (1992 to 2018), including 22,495 participating individuals aged 20 to 74 residing in the canton of Geneva. The study uses Moran's I local spatial statistics. We also investigate whether socio-demographic and food environment characteristics are associated with the spatial clusterings identified, using both global ordinary least squares (OLS) modelling and local geographically weighted regression (GWR) modelling.

Results: We identified clear spatial clusters of Na:K ratios and Na and K intakes. RGP modelling outperformed OLS models and revealed spatial variation in associations between explanatory and outcome variables. Older age, being female, higher education and less access to supermarkets were associated with a higher Na:K ratio, while the opposite was observed for Swiss nationals. Socio-demographic characteristics explained a large proportion of the clusters identified. Socio-demographic characteristics and the food environment differed significantly between individuals in the clusters of high and low Na:K ratios, and high and low Na and K intakes.

Conclusions: These results could guide priority interventions based on location and adapted to the characteristics of the populations identified.

Link to the article in English