The German LAKE-score reliably predicts urinary and dietary potential renal acid load: a three-armed translational...

Evidence supports kidney injury from a high potential renal acid load (PRAL). Existing predictive equations to estimate the PRAL have important limitations and require either a 24-h urine collection or the estimation of an individual's nutrient intake. The LAKE (load of acid to kidney evaluation) score offers a more pragmatic solution; however, the score has never been translated into the German language.

We translated the LAKE score into German, and validated it in a three-armed study in a healthy population comprised of omnivores, lacto-ovo-vegetarians and vegans. Using weighed food diaries, we estimated the participants' dietary PRAL (PRAL_R). The urinary PRAL (_UPRAL) was calculated based on 24-h urine collection-derived ionogram data. Correlation analyses were run to examine the score's validity. Intraclass correlation coefficients (ICC) were calculated to determine the score's reliability.

The study sample comprised 89 individuals. Results suggested a strong correlation between the long version of the LAKE score and the _UPRAL (r_p = 0.54, p < 0.001), which is considered an objective measure for the dietary exposure to precursors of non-volatile acids. Likewise, we observed a significant correlation between the PRAL_R and the LAKE score (r_p = 0.65, p < 0.001). Associations were comparable when using the short version of the LAKE score. Both scores indicated good reliability (ICC of the long version: 0.86; ICC of the short version: 0.87).

The German version of the LAKE score is a rapid, inexpensive and feasible tool for an initial PRAL evaluation in a clinical context, characterized by a good validity and reliability. Results suggest that the German LAKE score could be suitable as an estimate for an individual's PRAL, and could also guide clinicians to make dietary recommendations and monitor PRAL-relevant changes in individual patients.