Sodium intake in Germany estimated from sodium excretion measured in spot urine samples

Abstract

Background: Population sodium intake and its impact on public health has been a subject of a critical scientific debate for many years. The German Health Interview and Examination Survey for Adults (DEGS1) facilitate the biomarker-based estimation of sodium intake of the German population, although using spot urine concentrations to extrapolate to daily excretion estimates is associated with uncertainties that should be considered. Methods: Casual spot urine samples of 6910 German adults collected in DEGS1 were used to representatively estimate sodium intake of the German population. To extrapolate from spot urine concentrations to daily sodium excretion, five published equations were applied, and the results were compared to recommended sodium intake values. Results: The estimated means range from 166-230 mmol/d (men) and from 124-194 mmol/d (women). The variability of results also differs between applied equations; interquartile ranges vary between 41 and 133 mmol (men) and 21 and 118 mmol (women). Conclusions: Regardless of the applied equation, most German adults consume much more sodium than recommended by several institutions. To reduce uncertainty and to fully exploit the potential of biomarker-based estimates of sodium intake, either the sampling strategy should be expanded or the extrapolation from spot urines to daily intake should be refined.