Malnutrition is a common complication on peritoneal dialysis (PD) patients and a risk factor for morbidity and mortality. The prevalence of severe malnutrition is 5% to 10%, whereas mild to moderate malnutrition occurs in 30% to 50%. Reasons for low nutritional intake and anorexia in continuous ambulatory peritoneal dialysis (CAPD) patients are summarized as follows:
Factors not associated with mode of dialysis:
-Insufficient removal of low-molecular-weight toxins due to under dialysis.
-Cumulation of middle molecules with central anorectic effects.
-Loss of metabolizing renal tissue.
-Tastelessness of renal diet and altered taste perception.
-Metabolic Acidosis.
-Increased serum leptin levels.
-Endocrinologic levels.
-Gastroparesis and delayed gastric emptying
-Side effects of drugs.
-Infections(e.g. peritonitis)
-Comorbidity ( e.g.., Cardiovascular diseases)
-Psychosocial factors(e.g.., Depression)
-Low physical activity
-Advanced age
-Long duration of dialysis
-Late referral to dialysis.
Factors associated with the mode of dialysis
- Amino acid, vitamin, and protein losses.
-Glucose absorption
-Subjective feeling of fullness from the dialysate in the abdomen.
-High peritoneal transport rates.
Several studies showed increased weight gain during the first 2 years of PD treatment. Reported weight gain may be cause by glucose absorption from the dialysate, representing additional energy intake. Longitudinal studies, however, this initial weight gain is followed by a progressive impairment of nutritional status over time. An increase in total body water also can cause weight gain despite reduced daily protein and energy intake. This is more frequent after loss of residual renal function. An increase in body fat is positively correlated with the dialysate glucose concentration. Diabetic or female patients gain significantly more fat over time on PD than do non diabetic or male patients.
The required protein intake of PD patient is almost two fold higher than that of normal adults(1.2g/kg body weight in PD patients versus 0.6 to 0.7 g/kg body weight in normal adults). Metabolic balance studies showed that, with "unmeasured nitrogen losses" (e.g. sweat, skin desquamation, respiration) of 0.5g/day, the protein intake should be at least 1.1g/kg/day to avoid negative nitrogen balance. Consider the variability of each patients, a protein intake of 1.2g to 1.3g/kg/day is preferred.
Reference: Handbook of Nutrition and the Kidney; A Lippincott Williams & Wilkins Handbook.
Video 1. Example of a Renal Diet.
Video 2. A video of a PD patient sharing her own Peritoneal dialysis diet.
-Other supplementary information to be followed soon.