**3.2 Impact of dialysis modality**

258 Progress in Hemodialysis – From Emergent Biotechnology to Clinical Practice

associated with an increased inflammatory response with elevated solute vascular cell adhesion molecules (VCAM-1) and C-reactive protein (CRP) levels in PD patients (Wang AY, Lam et al, 2005), possibly as a result of impaired renal elimination of proinflammatory cytokines and increased cytokine generation (Witko-Sarsat, Descamps-Latscha et al, 1997). Conversely, the presence of inflammation also accelerated the decline of RRF (Shin, Noh et

Malnutrition is a common serious problem in dialysis patients, may be result of multiple factors including impairments in protein and energy metabolism, hormonal imbalances and poor food intake because of anorexia (Ikizler, Hakim et al, 1996). Dialysis dose may affect nutritional status and low dialysis efficacy is associated with higher rates of morbidity and mortality (Gotch, Sargent, 1985; Bergstrom, Lindholm, 1993). RRF contributes significantly to the appetite and total caloric intake (Wang, Sea et al, 2001; Wang, Sea et al, 2005), and overall nutritional status assessed using subjective global assessment, handgrip strength, or lean body mass in both HD and PD patients. Nutritional status is closely related to inflammation. In our study (Brener, Thijssen et al, 2008) anuric HD patients were older with lower baseline serum albumin and showed a trend toward greater length of stay for all causes, and all cause mortality including infectious mortality. Analysis of albumin kinetics performed in HEMO Study showed that a decrease in serum albumin in adequately dialysed patients was mostly due to an increase in the level of inflammation, rather that a decrease in protein

 Avoidance of nephrotoxic insults (NSAIDs, radiocontrast agents, aminoglycosides) Antihypertensive medications (ACE-inhibitors and calcium channel blockers)

Decline of RRF is an unavoidable phenomenon caused by the degenerative and fibrosis process of chronic kidney disease (CKD). However, the rate of RRF loss is different among patients and may be affected by other factors such as patient-related factors, treatment modalities and practice patterns (Jansen, Hart et al, 2002). Patient-related factors include age, causal nephropathy and comorbid conditions. Decline of RRF has been shown to be age dependent (Hung, Young, 2003). Intercurrent events such as recurrent blood pressure drop during HD, cardiac events and sepsis may precipitate loss of RRF. Diabetics on PD have been shown to have a more rapid decline in RRF than nondiabetics (Singhal, Bhaskaran et al, 2000). Comorbid conditions, including congestive heart failure, poorly controlled hypertension, and coronary artery disease, also are associated with faster rates of RRF decrease (Shin, Noh et al, 1999). Patients with CKD secondary to glomerular disease lose RRF more rapidly than those with tubulointerstitial disease (Iest, Vanholder et al, 1989). In a large multicenter study, the majority of patients with adult polycystic kidney disease were

al, 1999).

**2.5 RRF and nutritional status** 

intake (Kaysen, Dubin et al, 2000).

Table 3. Preservation of RRF

**3.1 Patient-related factors** 

PD modality

**3. Preservation of RRF (Table 3)** 

Avoidance of ECF volume depletion

Observational studies showed the advantage of PD compared to HD in preserving RRF (Moist, Port et al, 2000; Rottembourg, Issad et al, 1983; Misra, Vonesh et al, 2001) but data from prospective randomized trials are lacking. PD is associated with better hemodynamic stability that may minimize ischemic renal insults and avoidance of the extracorporeal circulation of HD that promotes systemic inflammation, oxidative stress, and subsequent kidney injury (Rottembourg, Issad et al, 1983). Treatment with ultrapure dialysate and biocompatible membranes has been shown to slow the loss of RRF in incident HD patients (Schiffl , Lang et al, 2002). It has been suggested use of PD as an initial dialysis modality in patients with RRF to maximize RRF conservation and thus survival for patients on dialysis.
