Monitoring of Nutritional Status in Patients with Chronic Kidney Disease
It is important that your nutritional status is checked regularly, particularly in later stages of chronic kidney disease (predialysis stage 4 to 5, and dialysis), when the risk for protein-energy-malnutrition and for fluid overload increases.
Assessment tools for the monitoring of nutritional status
You can quantify some basic measurements by yourself: body weight and body mass index (BMI). However, their validity concerning your nutritional status is limited, because they don´t give information about the composition of your body tissues. For example, if you suffer from fluid overload, your body weight and BMI will increase, but at the same time you can be malnourished and suffer from muscle degradation. Thus, body weight and BMI are essential measurements to get an approximate hint about your nutritional status, and they can be measured easily. Particularly in dialysis, daily measurements of body weight are crucial to monitor the fluid load of your body.
To get more precise information about your nutritional status, your doctor may perform some additional measurements. Those may include:
- Subjective global assessment (SGA): It contains a questionnaire and some clinical investigations. The result can be A (well-nourished), B (moderately malnourished) or C (severely malnourished).
- Anthropometry: Anthropometric screening methods to assess fat and lean body mass include the measuring of four-site skin fold thickness, mid-arm-circumference, and mid-arm-muscle-circumference.
- Normalized protein nitrogen appearance (nPNA): It measures your nitrogen balance, and thus provides an assessment of your dietary protein intake.
- Lab values such as the concentration of albumin and prealbumin or cholesterol in your blood, which give roughly information about the content of protein and lipids inside your body.
Technical investigations like bioelectrical impedance analysis (BIA) or dual X-ray absorptiometry (DEXA), which give precise information about your body composition (amount of fat, bone, muscles, water)
- Fouque D, Vennegoor M et al. EBPG Guideline on Nutrition. NDT 2007; 22(Supplement 2): ii45.