Criteria for the Clinical Diagnosis of Protein Energy Wasting in Patients With Kidney Disease

Criteria for the Clinical Diagnosis of Protein Energy Wasting in Patients With Kidney Disease

Serum chemistry and other laboratory markers

• Serum albumin <3.8 g/dL (Bromcresol Green)
• Serum prealbumin (transthyretin) <30 mg/dL
• Serum cholesterol <100 mg/dL
• Serum biochemistry: transferrin, urea, triglyceride, bicarbonate
• Hormones: leptin, ghrelin, growth hormones
• Inflammatory markers: CrP, IL-6, TNF-α, IL-1, SAA
• Peripheral blood cell count: lymphocyte count or percentage

Body mass and composition

• Body mass index <22 kg/m ² (<65 years) <23 kg/m ² (>65 years)
• Unintentional weight loss over time: 5% over 3 months or 10% over 6 months
• Total body fat percentage <10%
• Weight-based measures: weight for height
• Total body nitrogen
• Total body potassium
• Energy-beam based methods: DEXA, BIA, NIR
• Underwater weighing and air displacement weighing
• 14 K Dalton fragment of actomyosin
• Microarrays
• Muscle fiber size
• Relative proportions of muscle fiber types
• Muscle alkaline soluble protein
• Computed tomography and/or magnetic resonance imaging of muscle mass

Muscle mass

• Muscle wasting: reduced muscle mass 5% over 3 months or 10% over 6 months
• Reduced mid-arm muscle circumference area (>10% of reduction in relation to 50th percentile of reference population)
• Urinary creatinine appearance

Dietary intake

• Unintentional low dietary protein intake: <0.80 g/kg per day for at least 2 months for dialysis patients or <0.6 g/kg per day for patients on CKD stages 2–5

Appetite, food intake, and energy expenditure

• Appetite assessment questionnaires
• Population based dietary assessments: food frequency questionnaires
• Measuring energy expenditure by indirect or direct calorimetry

Nutritional scoring systems

• SGA and its modifications
• Malnutrition-Inflammation Score

BIA , bioelectrical impedance analysis; CRP , C-reactive protein; DEXA , dual energy x-ray absorptiometry; IGF-1 , insulin-like growth factor 1; IL , interleukin (e.g., IL-1 and IL-6); NIR , near-infrared interactance; SAA , serum amyloid A; SGA , subjective global assessment of nutritional status; TNF-a a, tumor necrosis factor alpha.