Mediterranean-like Dietary Pattern and Serum Phosphorus in Hemodialysis: Beyond Food Phosphorus Content.

BACKGROUND: Disturbances in mineral and bone metabolism are common in hemodialysis (HD) patients, increasing the risk of hyperphosphatemia. Dietary phosphorus restriction remains a cornerstone of management, often leading to stringent dietary recommendations. This study aimed to explore whether adopting a Mediterranean-like dietary pattern (Med-LDP), compared to a Western-like dietary pattern (West-LDP) was associated with serum phosphorus levels. METHODS: This cross-sectional multicenter study included 564 HD patients from 37 dialysis centers. Dietary intake was assessed using a food frequency questionnaire, and dietary patterns were identified through principal component analysis based on 22 food groups. Associations between dietary patterns, phosphorus intake, and serum phosphorus levels were evaluated using correlations tests and linear regression analyses adjusted for demographic, clinical, nutritional, and dialysis-related factors. RESULTS: Two different dietary patterns were identified: a "Mediterranean-like" pattern characterized by a higher intake of vegetables, legumes, fruit, starchy products, fish, olive oil, eggs, bakery products, and alcohol; and a "Western-like" characterized by a higher intake of soft drinks, red meat, fried and salted foods, fast food, and caffeine. Despite significantly higher intakes of energy, protein, carbohydrates, phosphorus, potassium, and fiber, patients following the Med-LDP exhibited lower serum phosphorus levels, calcium-phosphorus product, and PTHi concentrations. No differences were observed in serum potassium levels. The correlation between phosphorus intake and serum phosphorus was weak and not statistically significant. The West-LDP was positively associated with serum phosphorus levels and remained an independent predictor after adjustment for potential confounders. However, after further adjustment for the prescribed dosages of phosphate binders, vitamin D supplementation and analogs, as well as calcimimetics, the association was no longer statistically significant. CONCLUSIONS: HD patients following a Med-LDP exhibited lower serum phosphorus levels despite a higher phosphorus intake. These findings suggest that the overall dietary pattern may be a more important determinant of phosphorus homeostasis than total phosphorus intake alone.