MO593CONTROLLING DIETARY PHOSPHORUS IN CHRONIC KIDNEY DISEASE STAGES 1 AND 2 DECREASES PROTEINURIA AND PREVENTS DECLINE IN RENAL FUNCTION
Authors: Saxena Anita , Gupta Amit , Sachan Trisha , Kapoor Vishwas , Kumar Anup , Sharma Sachin 
Published: May 2021

Abstract

Background and Aims
High phosphorus intake is known to cause renal and vascular calcification and renal tubular injury and albuminuria. Dietary phosphorus restriction is therapeutic for controlling disordered phosphorus homeostasis and for improving cardiovascular outcomes in CKD. However, early restriction of dietary phosphorus is not advocated Aim: To evaluate if early control of dietary phosphorus ameliorates proteinuria, prevents decline in glomerular filtration rate and prevents increase in FGF-23

Method
One year longitudinal study on 79 CKD patients in stages 1 and 2. eGFR, serum creatinine , phosphorus, calcium, FGF-23, soluble α-Klotho iPTH FGF 23, blood pressure, were evaluated and compared with 35 controls. 3 days dietary intake was taken using standard methodology on first visit, 6 and 12 months. CKD patients were grouped based on dietary phosphorus intake: Group 1 (n 42): normal phosphorous intake (&lt;1000mg/day) and Group 2 (n=37; 17 in CKD 1; 20 CKD 2): high phosphorous intake (&gt;1000mg/d). Patients in Group 2 were educated on high and low phosphorus foods and counselled to avoid fresh and frozen and processed meat, eggs, nuts and seeds, chocolates, packaged food, phosphorus-containing food additives and counselled to adopt a plant-based diet, for low phosphorus availability/absorption diet with directed diet plan. Lentils and pulses, milk and milk products (hard cheese, ice-creams, custards, cottage cheese, pudding, yoghurt), bran and whole wheat cereals were restricted up to 1-2 servings a day Data were analysed using SPSS.

Results
At baseline there was no significant difference in the GFR (group1 85.00±18.64 ml/min vs group 2 82.53±16.30ml/min), serum creatinine between groups. In group2 ; GFR, sKlotho, serum phosphorus and FGF-23 correlated significantly with dietary phosphorus intake. In group 2, FGF-23, Serum phosphorus, dietary protein and phosphorus intake were significantly higher and sKlotho was significantly lower than group 1. There was significant difference in serum phosphorus (p 0.000), iPTH, (p 0.004), FGF23 (p0.000), Klotho (p0.000), urinary protein (p0.000), dietary protein (Group 1 37.57±3.40; Group 248.79±5.86 p 0.000) and phosphorus (Group 1868.96±69.99 mg/d and Group 2 1312.26±137.57 mg/d p 0.000) intake and dietary phosphorous to protein ratio (p 0.000) between groups 1 and 2.. After dietary intervention in group 2 GFR increased from 80.93±15.34 to 84.11±15.38 in six months and to 87.43±18.27 ml/min at 12 months p 0.012, and urinary protein declined to 22.01±3.39 mg/mL. FGF 23 declined from 60.67±6.26 to 58.00±7.07 to 53.29±9.48 pg/mL at 12 months. Urinary phosphorus excretion increased from 574.37±214.22 to 624.64±137.67 at 12 months. Dietary phosphorus protein to ratio reduced from 27.16±4.35 to24.75±4.34 p 0.000 at 12 months

Conclusion
CKD patients should be cautioned and counselled on their first visit on the impact of dietary phosphorus intake on the progression of CKD and development of CVD.