Strategies for Phosphate Control in Patients With CKD

Abstract

Hyperphosphatemia is a common complication in patients with chronic kidney disease (CKD), particularly in those requiring renal replacement therapy. The importance of controlling serum phosphate has long been recognized based on observational epidemiological studies that linked increased phosphate levels to adverse outcomes and higher mortality risk. Experimental data further supported the role of phosphate in the development of bone and cardiovascular diseases. Recent advances in our understanding of the mechanisms involved in phosphate homeostasis have made it clear that the serum phosphate concentration depends on a complex interplay among the kidneys, intestinal tract, and bone, and is tightly regulated by a complex endocrine system. Moreover, the source of dietary phosphate and the use of phosphate-based additives in industrialized foods are additional factors that are of particular importance in CKD. Not surprisingly, the management of hyperphosphatemia is difficult, and, despite a multifaceted approach, it remains unsuccessful in many patients. An additional issue is the fact that the supposedly beneficial effect of phosphate lowering on hard clinical outcomes in interventional trials is a matter of ongoing debate. In this review, we discuss currently available treatment approaches for controlling hyperphosphatemia, including dietary phosphate restriction, reduction of intestinal phosphate absorption, phosphate removal by dialysis, and management of renal osteodystrophy, with particular focus on practical challenges and limitations, and on potential benefits and harms.

Inflammation and Premature Ageing in Chronic Kidney Disease

“…Because of the above-mentioned evidence of a direct association between P i and premature ageing in CKD, non-pharmaceutical prevention strategies could potentially reduce the burden of disease, including changes in lifestyle. However, there is a lack of studies linking diets that lower P i levels to a beneficial clinical outcome [86,87]. Furthermore, whereas low-P i diets can reduce FGF-23 levels in CKD [88], there was no dose-dependent effect of P i lowering on FGF-23 reduction when low-and very low phosphate diets were compared in a recent short-term, randomized, crossover trial in 35 ESKD patients [89].…”

Phosphate clearance in peritoneal dialysis

“…( *** ) and ( ** ) denote global p value < 0.001 and < 0.01, respectively, during multicomparison procedure. (1,2,3) Superscripts mean significant difference (p < 0.05) between the current value and the therapy listed in bracket. Number of measurements 120 (33%) 61 (17%) 187 (51%) 368…”

“…Urine volume, mL/day ( *** ) 427.54 ± 472.38 (2) 59.43 ± 149.96 (1,3) 381.43 ± 492.54 (2) 343.09 ± 464.15…”

Subjective global assessment of nutrition, dialysis quality, and the theory of the scientific method in Nephrology practice

“…96,97 Dietary restriction of phosphorus, unsurprisingly, has not been clearly demonstrated to correlate with decreased mortality on dialysis. 96,98 Furthermore, one could argue that a higher serum phosphorus level may mean different things in different patients. If much of the phosphorus load is taken as food additives, the association of serum phosphorus and increased cardiovascular mortality risk may partially reflect the harmful effects of the latter or it may be a marker of poor dietary habits (ie, eating junk food).…”