Objective: To evaluate the dietary habits of hemodialysis patients with hyperphosphatemia and the effects of a dietetic intervention focused on limiting dietary phosphate load.
Design: Cross-sectional dietary evaluation and prospective intervention study.
Setting: Hospital hemodialysis units of Pisa and Pistoia, Italy. Subjects Forty-three stable adult hemodialysis patients, 20 of whom had phosphorus serum levels >5.5 mg/dL.
Intervention: Analysis of dietary composition and of the effects of individual dietetic counseling in an attempt to reduce phosphorus intake while preserving the same protein intake.
Main outcome measures: Differences in nutrient intake between normophosphatemic and hyperphosphatemic patients, and changes in dietary phosphorus and phosphorus-protein ratio, serum phosphate, and calcium-phosphate product after dietetic intervention.
Results: No major differences in nutrient intake were detected between hyperphosphatemia and normophosphatemia patients, apart from a lower phosphorus-protein ratio (13.1 +/- 1.7 versus 14.1 +/- 2.1 mg/g, P < .05) in the former. After dietetic intervention in the hyperphosphatemia patients, phosphate and calcium intake decreased significantly (by 100 mg on average), whereas dietary protein did not change. A further decrease of the dietary phosphate-protein ratio (12.5 +/- 1.8 mg/g, P < .05) also occurred. Serum phosphate showed a trend to decrease in the intervention group, whereas the serum calcium-phosphate product decreased significantly (from 66.8 +/- 13.1 to 61.0 +/- 13.8 mg2 /dL2 , P < .05).
Conclusions: In compliant and motivated patients, individual dietetic counseling may be useful in reducing phosphate load and in limiting the phosphate burden related to an adequate protein intake, with a potentially favorable impact on calcium-phosphate retention. A phosphate-controlled diet has a role in an integrated therapeutic approach to hyperphosphatemia and positive calcium-phosphorus balance in hemodialysis patients.