The Role Of Low-protein Diet On Hyperphosphatemia In Maintenance Hemodialysis Patients

Hyperphosphatemia is a common complication with maintenancehemodialysis patients that can lead to vascular and soft tissue calcification,it is an independent risk factor for increased mortality. Dietary intervention,phosphate（P） removal during dialysis and, especially, phosphate bindersare current methods for the management of hyperphosphatemia. A highlysignificant correlation was observed between protein and P, so we canprescribe a low-protein diet with low-phosphate to controlhyperphosphatemia. Additional protein restriction may impose the risk ofprotein malnutrition, which is also a common complication withmaintenance hemodialysis patients. In this study, nutritional status wereinvestigated first, learning the incidence of malnutrition and the nutritionalstatus of maintenance hemodialysis patients. Based on the above outcomes,patients with hyperphosphatemia and well nutritional condition wereselected to the next section. Patients received low-protein diet under theclosely observation of nutritional status. The patients were forced towithdraw immeediately if the nutritional status tend to be terrible.The malnutrition-inflammation score, bioelectrical impedanceanalysis, anthropometric, laboratory values and dietary intake were used toevaluate the nutritional status of patients. A total of74patients werereceived the evaluation. The mean malnutrition-inflammation score was（3.42±0.27）.12.16%of patients studied were malnourished. According tothe score of MIS, patients were distributed to3groups. Compared to thegroup of0to2patients, the group of greater than or equal to5patients lessthan the body protein index, body fat index (P<0.05). Patients were distributed as age and sex. Compared to the resident of Beijing urban andrural areas with same sex, age and ethnic, the youth, the middle-aged, theold male patients, the middle-aged and the old female patients were lessthan the average value of body protein index（P<0.05）, the middle-agedmale patients were less than body fat index（P<0.05）,the old male patientswere more than body fat index（P<0.05）. It is clear that, among themaintenance hemodialysis patients, as the nutritional status trend worse, theprotein and body fat were reduced. Compared to the healthy, the proteinwas consumed in the maintenance hemodialysis patients.A total of28patients with hyperphosphatemia from74patients withless than5of MIS were randomized to low protein diet group (group A,n=16, the protein intake was0.8g·kg-1·d-1) and normal protein dietgroup(group B, n=12，the protein intake was1.2g·kg-1·d-1)，the nutritionstatus, serum calcium, phosphrous and intact parathyroid hormone wereevaluated before and after three months and six months of treatment. Therewere no significant differences in serum phosphorus, corrected calciumbetween2groups before treatment (P>0.05). There was difference inserum phosphorus, calcium-phosphorus products6months after treatment(P<0.05)，and lower in group A than in group B (P<0.05), but there was notdifference between pre-and post-treatments in group B (P>0.05). Thenutritional status of group A，including albumin, prealbumin, transferrin,total cholesterol levels and malnutrition-inflammation score were stable,not differing from group B (P>0.05). There were no significant differencesin anthropometric indicators between2groups before and after treatment(P>0.05). In summary, long-term treatment with low protein diet caneffectively and safety reduce the level of serum phosphorus, improving themetabolic acidosis and inflammatory state, not effecting nutritional statusremarkably.