How to manage decreased appetite in patients undergoing dialysis?

Management of Decreased Appetite in Dialysis Patients

Optimize dialysis adequacy first—ensure weekly Kt/Vurea ≥2.0 for hemodialysis patients and creatinine clearance ≥60 L/week/1.73 m² for high/high-average transporters (or ≥50 L/week/1.73 m² for low/low-average transporters) in peritoneal dialysis patients, as inadequate dialysis directly causes uremic anorexia through toxin accumulation. 1

Immediate Assessment and Correction of Dialysis Adequacy

• Measure dialysis adequacy immediately in any dialysis patient presenting with decreased appetite, as Kt/Vurea <2.0 per week directly causes nausea, vomiting, and anorexia through uremic toxin accumulation 2, 1
• Inadequate dialysis is the primary reversible cause of appetite suppression, producing gastrointestinal symptoms that interfere with food intake 2, 3
• Increasing dialysis dose may improve appetite by reducing uremic toxins, though evidence for improved nutritional markers from dose increases alone remains limited 1

Nutritional Monitoring and Protein Intake Goals

• Monitor protein equivalent of nitrogen appearance (nPNA) targeting ≥0.9-1.1 g/kg/day, as values below this range indicate inadequate protein intake 1
• Assess serum albumin (maintain above lower limit of laboratory normal range), subjective global assessment (SGA), and edema-free body weight trends regularly 1
• Never restrict protein intake to <0.8 g/kg/day in dialysis patients—malnutrition poses a greater mortality risk than theoretical benefits of protein restriction 1

Nutritional Support Interventions

Oral Nutritional Supplements (First-Line)

• Provide oral nutritional supplements (ONS) when oral intake fails to meet ≥70% of daily macronutrient requirements, as ONS can improve nutritional status without negatively affecting regular food consumption 1
• ONS combined with dietary counseling should be attempted before considering intradialytic parenteral nutrition (IDPN) 1
• Most patients with poor overall appetite (85%) still identify at least three specific protein foods for which they have good appetite—focus on increasing intake of these preferred foods 4

Intradialytic Parenteral Nutrition (Second-Line)

• Reserve IDPN for malnourished hemodialysis patients who fail to respond to or cannot tolerate ONS or enteral nutrition 1
• IDPN provides nutrients during the 3-4 hour hemodialysis session three times weekly 1

Address Contributing Factors

Metabolic and Inflammatory Causes

• Evaluate for chronic inflammation, as proinflammatory cytokines (TNF-α, IL-6) are directly associated with diminished appetite in dialysis patients 2, 1
• Assess for metabolic acidosis, insulin resistance, and altered amino acid profiles that contribute to appetite suppression 2
• Screen for gastroparesis and other comorbidities that may hamper adequate nutrition 1, 3

Psychological Factors

• Screen for depression and anxiety using validated tools (Beck Depression Inventory, Beck Anxiety Inventory), as appetite scores correlate significantly with psychological distress 5
• Treatment of psychological conditions may be useful to increase appetite and nutritional status 5
• Female patients have a higher proportion of diminished appetite and require closer monitoring 5

Treatment-Related Factors

• Review dietary restrictions to ensure they are not inappropriately stringent, as overly restrictive diets contribute to malnutrition 2
• Evaluate dialyzer membrane bio-incompatibility and nutrient losses during dialysis 2
• Address mechanical impairments to food intake such as lack of dentures 2

Individualized Dietary Planning

• Work with a registered dietitian to create an individualized meal plan that meets nutritional recommendations for dialysis patients regarding micro- and macro-nutrients while addressing appetite concerns 6
• Monitor laboratory values and food intake closely during any dietary intervention 6
• Avoid popular diets that could induce adverse metabolic complications (high protein types, food-combining diets, unusually large portions of fruits and vegetables) 6

Physical Activity and Muscle Mass Preservation

• Incorporate exercise training (aerobic and resistance training) to increase muscle mass, as maintenance of muscle mass is important in reducing cardiovascular risk and mortality 6
• Physical activity should be undertaken in combination with behavioral therapy that assesses motivation levels 6
• Low muscle mass combined with high body fat is associated with increased risk of death, even in patients with low BMI 6

Common Pitfalls to Avoid

• Do not assume poor overall appetite means poor appetite for all foods—82% of patients with poor overall appetite identify at least three nonprotein foods they enjoy 4
• Do not delay addressing inadequate dialysis while pursuing other interventions—uremic toxin accumulation is often the primary driver 2, 3
• Avoid focusing solely on BMI, as it is complicated by excess fluid weight and muscle wasting in dialysis patients 6
• Do not overlook that hospitalized dialysis patients often ingest only 66% of protein and 50% of energy requirements even when needs increase during acute illness 2