Metabolic Effects of Incremental Doses of Intraperitoneal Amino Acids on Automated Peritoneal Dialysis

Risk factors for peritoneal dialysis–associated peritonitis

The purpose of this study was to summarize the pathogens that cause peritoneal dialysis (PD)-associated peritonitis and to identify risk factors for PD-associated peritonitis. This retrospective study included 115 end-stage renal disease (ESRD) patients receiving PD therapy. Patients were categorized into two groups: peritonitis group (n = 41) and non-peritonitis group (n = 74). Clinical data and laboratory tests were collected from medical records. The multivariate logistic regression model was used to evaluate associations between PD-associated peritonitis and potential risk factors. PD-associated peritonitis occurred 54 times in 41 patients. The most frequently identified pathogen was Gram-positive cocci (57.78%). Multivariate logistic regression analysis showed that serum albumin (β = –0.208, P < 0.001), blood phosphorus concentration (β = –1.732, P = 0.001), gastrointestinal disorders (β = 1.624, P = 0.043), and use of calcitriol (β = –2.239, P = 0.048) were significantly correlated with PD-associated peritonitis. Receiver operating characteristic (ROC) curves showed that the areas under the curve were 0.832 for serum albumin and 0.700 for blood phosphorus concentration with optimal cut-off values of 29.1 g/L for serum albumin and 1.795 mmol/L for blood phosphorus concentration. Gram-positive coccus is the major pathogen responsible for PD-associated peritonitis. Serum albumin <29.1 g/L, blood phosphorus concentration <1.795 mmol/L, and intestinal disorders are risk factors for PD-associated peritonitis, whereas the use of calcitriol can reduce the risk of PD-associated peritonitis.

Association of initial twice-weekly hemodialysis treatment with preservation of residual kidney function in ESRD patients

BACKGROUND

Residual kidney function (RKF) has consistently been a predictor of greater survival in maintenance hemodialysis (MHD) patients. The relationship between hemodialysis (HD) treatment frequency and RKF preservation has not been well examined. We hypothesized that initial twice-weekly HD helps in maintaining a longer RKF.

METHODS

In a dialysis center in Shanghai, 168 ESRD patients were screened and finally 85 patients were identified for this main cohort study. We first examined these 85 MHD patients; 30 of them were initiated with twice-weekly HD for 6 months or longer and 55 patients were started and maintained on thrice-weekly HD treatment. Then a subcohort study in 48 incident MHD patients was implemented to assess the independent risk factors responsible for RKF decline during the first year of HD therapy. Multivariate logistic regression analysis was then employed to examine the odds ratio of RKF loss.

RESULTS

The main cohort study showed that the clinical outcomes were almost the same between the two groups in 85 patients, but the percent of patients with RKF loss was significantly lower in the twice-weekly group compared with the thrice-weekly group, especially during the first year of HD initiation. In the 48 incident MHD patients, we found no significant differences between the two groups except for variations in the HD frequency, weekly Kt/V. The multivariate analysis showed that factors such as the male gender, HD frequency, URR and intradialytic hypotension episode were associated with RKF loss, and the odds ratio of RKF loss for each additional HD treatment per week was 7.2.

CONCLUSION

Twice-weekly HD during the first year of dialysis therapy appears to be associated with better RKF preservation.

Effects of peritoneal dialysis on protein metabolism

Protein-energy wasting is relatively common in renal patients treated with haemodialysis or peritoneal dialysis (PD) and is associated with worse outcome. In this article, we review the current state of our knowledge regarding the effects of PD on protein metabolism and the possible interactions between PD-induced changes in protein turnover and the uraemia-induced alterations in protein metabolism. Available evidence shows that PD induces a new state in muscle protein dynamics, which is characterized by decreased turnover rates and a reduced efficiency of protein turnover, a condition which may be harmful in stress conditions, when nutrient intake is diminished or during superimposed catabolic illnesses. There is a need to develop more effective treatments to enhance the nutritional status of PD patients. New approaches include the use of amino acid/keto acids-containing supplements combined with physical exercise, incremental doses of intraperitoneal amino acids, vitamin D and myostatin antagonism for malnourished patients refractory to standard nutritional therapy.