DASH diet, Reduced Rank Regression Dietary Patterns and relations with kidney function in the CHRIS general population study

ObjectiveWe assessed dietary patterns (DPs) using the pre-defined Dietary Approaches to Stop Hypertension (DASH) score and reduced rank regression (RRR) to evaluate their association with estimated glomerular filtration rate (eGFR) in a general population sample. MethodsWe analysed cross-sectional data from 6,133 healthy adult participants of the Cooperative Health Research In South Tyrol (CHRIS) study. Using self-reported food frequency questionnaire data, we derived the DASH-score and two RRR-based sex-specific DP-scores based on nine cardio-renal-metabolic parameters. We fitted sex-stratified linear and non-linear models to assess associations with creatininebased eGFR. ResultsMales with higher intake of cereals, whole grains, sugar, fruits, and legumes, and lower intake of beer, and red and processed meat (MDP1), exhibited higher eGFR levels. Coherently, high adherence to the DASH-style diet was associated with higher eGFR. In females, the associations varied by menstrual status. Among those with ceased menstruation, a low intake of meat, spirits, refined grains, beer, and fish, and a high intake of whole grains and dairy products was associated with higher eGFR. In females still experiencing regular menstruation, a high intake of beef, nuts, beer, legumes, fish, and coffee, and low intake of refined grains, (FDP2) was associated with lower eGFR. No association was observed with the DASH score in females. ConclusionOur findings confirm the DASH-style diet is associated with better kidney function in males, but not in females. By identifying sex-specific kidney function-oriented DPs, the RRR approach provides new insights into the diet-eGFR relation, highlighting in addition potential effect modification by menstrual status.