1 g greater LVMI (95% CI 0.5–1.6).118 However, analysis of the NHANES III data did not show any association between high dietary phosphate intake and mortality in 1105 CKD patients (HR 0.98 per 100 mg/dL increase (95% CI 0.93–1.03)).119

Few clinical trials have looked at lowering dietary phosphate absorption in participants with normal phosphate levels to prevent the complications of CKD-MBD. An experimental study using a rat model of CKD-MBD reported animals with reduced GFR fed a grain-based diet, see more compared with standard synthetic casein animal diets, had lower serum phosphate, urinary phosphate excretion and serum levels of FGF-23.120 The same investigators conducted a cross-over trial in nine patients (mean eGFR 32 mL/min) and compared vegetarian and meat diets. They reported decreased urine phosphate excretion, lower serum phosphate and decreased FGF-23 levels with a vegetarian diet

after 1 week.121 This study also highlighted that higher dietary phosphate intake was associated with increased FGF-23. Dietary phosphate counselling for CKD patients can be complex and patients are often confused by the multitude of recommendations. Simplifying the approach by asking them to eat more grains and less meat and less pre-prepared or packaged foods may potentially lead to increased dietary adherence and subsequent improved phosphate homeostasis. One study educating ESKD patients on dialysis to avoid phosphate-containing food additives resulted in modest improvements in hyperphosphataemia.122 However, further dietary studies are required in CKD patients as additives are increasingly being added PI3K inhibitor to processed and fast foods and the effect of dietary modifications on serum phosphate levels in early CKD is unclear. Despite the rapidly growing body of literature suggesting phosphate dysregulation is associated with increased morbidity and mortality in CKD, what remains to be established is whether early intervention

to prevent phosphate retention can impact on the development of the adverse clinical outcomes associated with CKD-MBD. To date, there has not been an adequately powered, placebo-controlled, multicentre RCT evaluating Dipeptidyl peptidase the effects of phosphate-lowering therapy on reduction of CVD burden in CKD patients. One of the first questions to help design an RCT addressing phosphate homeostasis in early CKD would be to determine the trigger for intervention or the abnormality that one should aim to correct. Hyperphosphataemia occurs late in CKD, at which point arterial or ventricular function may be impaired, so the approach should probably be to intervene before this occurs. Rising phosphate levels within the normal range maybe both a trigger for intervention and its target, but phosphate levels undergo circadian and dietary variation and fasting levels may also be uninformative, so this approach may not prove valuable.