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Evidence summaries

Dietary Interventions for Mineral and Bone Disorder in People with Chronic Kidney Disease

Low phosphorus intake may decrease serum phosphorus compared to normal diet in chronic kidney disease. Level of evidence: "C"

Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and blinding and incomplete outcome data), by imprecise results (few patients).

Summary

A Cochrane review [Abstract] 1 included 9 studies with a total of 634 subjects. Study duration ranged from 4 to 24 weeks. Only one study reported death; none of the included studies reported cardiovascular events or fractures. Calcium-enriched bread increased serum calcium (MD 0.16 mmol/L, 95% CI 0.51 to 0.31;1 trial, n=53, low-quality evidence), decreased serum phosphorus (MD -0.41 mmol/L, 95% CI -0.51 to -0.31; n=53, low-quality evidence) and decreased the calcium × phosphate product (MD -0.62 mmol²/L², 95% CI -0.77 to -0.47; n=53, low-quality evidence).

Very low protein intake was not superior to conventional low protein intake in terms of effect on serum phosphorus (MD -0.12 mmol/L, 95% CI -0.50 to 0.25; 2 studies, n=41), serum calcium (MD 0.00 mmol/L, 95% CI -0.17 to 0.17), or alkaline phosphatase (MD -22.00 U/L, 95% CI -78.25 to 34.25). PTH was significantly lower in the very low protein intake group (MD -69.64 pmol/L, 95% CI -139.83 to 0.54; 2 studies, n=41).

One study reported no significant difference in the number of deaths between low phosphorus intake and normal diet (RR 0.18, 95% CI 0.01 to 3.82; n=279). Low phosphorus intake decreased serum phosphorus (MD -0.18 mmol/L, 95% CI -0.29 to -0.07; 2 studies, 359 participants; I²=0%).One study reported post-haemodialysis supplements did not increase serum phosphorus compared to normal diet (MD 0.12 mmol/L, 95% CI -0.24 to 0.49; n=40).One study reported low phosphorus intake plus lanthanum carbonate significantly decreased fibroblast growth factor 23 (19 participants: MD -333.80 RU/mL, 95% CI -526.60 to -141.00), but did not decrease serum phosphorus (MD -0.10 mg/dL, 95% CI -0.38 to 0.58; n=19) or PTH (MD 31.60 pg/mL, 95% CI -29.82 to 93.02; n=19).

Clinical comments

Note

Date of latest search: 27 August 2015

    References

    • Liu Z, Su G, Guo X et al. Dietary interventions for mineral and bone disorder in people with chronic kidney disease. Cochrane Database Syst Rev 2015;(9):CD010350. [PubMed]

Primary/Secondary Keywords