Very low-protein diet plus ketoacids in chronic kidney disease and risk of death during end-stage renal disease: a historical cohort controlled study.

BACKGROUND: Very low-protein intake during chronic kidney disease (CKD) improves metabolic disorders and may delay dialysis start without compromising nutritional status, but concerns have been raised on a possible negative effect on survival during dialysis. This study aimed at evaluating whether a very low-protein diet during CKD is associated with a greater risk of death while on dialysis treatment. METHODS: This is an historical, cohort, controlled study, enrolling patients at dialysis start previously treated in a tertiary nephrology clinic with a very low-protein diet supplemented with amino acids and ketoacids (s-VLPD group, n = 184) or without s-VLPD [tertiary nephrology care (TNC) group, n = 334] and unselected patients [control (CON) group, n = 9.092]. The major outcome was survival rate during end-stage renal disease associated to s-VLPD treatment during CKD. The propensity score methods and Cox regression model were used to match groups at the start of dialysis to perform survival analysis and estimate adjusted hazard ratio (HR). RESULTS: In s-VLPD, TNC and CON groups, average age was 67.5, 66.0 and 66.3 years, respectively (P = 0.521) and male prevalence was 55, 55 and 62%, respectively (P = 0.004). Diabetes prevalence differed in the three groups (P < 0.001), being 18, 17 and 31% in s-VLPD, CON and TNC, respectively. A different prevalence of cardiovascular (CV) disease was found (P < 0.001), being similar in TNC and CON (31 and 25%) and higher in s-VLPD (41%). Median follow-up during renal replacement therapy (RRT) was 36, 32 and 36 months in the three groups. Adjusted HR estimated on matched propensity patients was 0.59 (0.45-0.78) for s-VLPD versus CON. Subgroup analysis showed a lower mortality risk in s-VLPD versus matched-CON in younger patients (<70 years) and those without CV disease. No significant difference in HRs was found between s-VLPD and TNC. CONCLUSION: s-VLPD during CKD does not increase mortality in the subsequent RRT period.

Cost-benefit analysis of supplemented very low-protein diet versus dialysis in elderly CKD5 patients.

BACKGROUND: Dialysis increases patient life expectancy but is associated with clinically severe and costly complications. Health and economic benefits could derive from postponing dialysis with a supplemented very low-protein diet (sVLPD). METHODS: An economic evaluation was conducted to compare benefits and costs of sVLPD versus dialysis in elderly CKD5 patients. Data from 57 patients aged >or=70 years, with glomerular filtration rate (GFR) 5-7 mL/min, previously participating in a clinical trial demonstrating non-inferior mortality and morbidity of starting sVLPD compared to dialysis treatment, were analysed: 30 patients were randomized to dialysis and 27 to sVLPD. A cost-benefit analysis was conducted, in the perspective of the National Health Service (NHS). Direct medical and non-medical benefits and costs occurring in 3.2 mean years of follow-up were quantified: time free from dialysis, cost of dialysis treatment, hospitalization, drugs, laboratory/instrumental tests, medical visits and travel and energy consumption to receive dialysis. Prices/tariffs valid in 2007 were used, with an annual discount rate of 5% applied to benefits and costs occurring after the first year. Sensitivity analyses were conducted to identify how estimates could vary in different contexts of applications. Results are reported as net benefit, expressed as mean euro/patient (patient-year). RESULTS: The opportunity to safely postpone initiation of dialysis of 1 year/patient on average translated into an economic benefit to the NHS, corresponding to 21 180 euro/patient in the first, 6500 euro/patient in the second and 682 euro/patient in the third year of treatment, with a significant net benefit in favour of sVLPD even in a worst-case hypothesis. CONCLUSION: The initiation of sVLPD in elderly CKD5 subjects is a safe and beneficial strategy for these patients and allows them to gain economic resources that can be allocated to further health care investments.