In individuals with chronic kidney disease, high dietary phosphorus (P) burden may worsen hyperparathyroidism and renal osteodystrophy, promote vascular calcification and cardiovascular events, and increase mortality. In addition to the absolute amount of dietary P, its type (organic versus inorganic), source (animal versus plant derived), and ratio to dietary protein may be important. Organic P in such plant foods as seeds and legumes is less bioavailable because of limited gastrointestinal absorption of phytate-based P. Inorganic P is more readily absorbed by intestine, and its presence in processed, preserved, or enhanced foods or soft drinks that contain additives may be underreported and not distinguished from the less readily absorbed organic P in nutrient databases. Hence, P burden from food additives is disproportionately high relative to its dietary content as compared with natural sources that are derived from organic (animal and vegetable) food proteins. Observational and metabolic studies indicate nutritional and longevity benefits of higher protein intake in dialysis patients. This presents challenges to providing appropriate nutrition because protein and P intakes are closely correlated. During dietary counseling of patients with chronic kidney disease, the absolute dietary P content as well as the P-to-protein ratio in foods should be addressed. Foods with the least amount of inorganic P, low P-to-protein ratios, and adequate protein content that are consistent with acceptable palatability and enjoyment to the individual patient should be recommended along with appropriate prescription of P binders. Provision of in-center and monitored meals during hemodialysis treatment sessions in the dialysis clinic may facilitate the achievement of these goals.

Objective: To determine whether dry weight gain accompanied by an increase in muscle mass is associated with a survival benefit in patients receiving maintenance hemodialysis (HD). Patients and MethOds:In a nationally representative 5-year cohort of 121,762 patients receiving HD 3 times weekly from July 1, 2001, through June 30, 2006, we examined whether body mass index (BMI) (calculated using 3-month averaged post-HD dry weight) and 3-month averaged serum creatinine levels (a likely surrogate of muscle mass) and their changes over time were predictive of mortality risk.Results: In the cohort, higher BMI (up to 45) and higher serum creatinine concentration were incrementally and independently associated with greater survival, even after extensive multivariate adjustment for available surrogates of nutritional status and inflammation. Dry weight loss or gain over time exhibited a graded association with higher rates of mortality or survival, respectively, as did changes in serum creatinine level over time. Among the 50,831 patients who survived the first 6 months and who had available data for changes in weight and creatinine level, those who lost weight but had an increased serum creatinine level had a greater survival rate than those who gained weight but had a decreased creatinine level. These associations appeared consistent across different demographic groups of patients receiving HD.cOnclusiOn: In patients receiving long-term HD, larger body size with more muscle mass appears associated with a higher survival rate. A discordant muscle gain with weight loss over time may confer more survival benefit than weight gain while losing muscle. Controlled trials of muscle-gaining interventions in patients receiving HD are warranted. Mayo Clin Proc. 2010;85(11):991-1001From the harold simmons center for chronic disease Research and epidemiology (K.K.-Z., e.s., j.j., n.n.) and division of nephrology and hypertension (K.K.-Z., j.d.K., R.M.), los angeles biomedical Research institute at harborucla Medical center, torrance, ca; ucla david Geffen school of Medicine (K.K.-Z., a.R.n., j.d.K., R.M.); department of Family health and/or epidemiology, ucla school of Public health, los angeles, ca (K.K.-Z., e.s., j.d.K.); salem veterans affairs Medical center, salem, va (c.P.K.); davita, el segundo, ca (a.R.n, M.K.); university of alberta, edmonton, alberta, canada (a.O.); and charité university school of Medicine, berlin, Germany and centre for clinical and basic Research, iRccs san Raffaele, Rome, italy (s.d.a.) the study was supported by dr Kalantar-Zadeh's research grants from the national institute of diabetes and digestive and Kidney diseases of the national institutes of health (R01 dK078106), the american heart association (0655776Y), and davita clinical Research (dcR), as well as a philanthropic grant from Mr harold simmons and an additional dcR grant for the division of nephrology & hypertension at harbor-ucla Medical center. drs nissenson and Krishnan are employees of davita. dr Kalantar-Zadeh is the medical director ...