Introduction. Maintenance hemodialysis (MHD) patients are at risk of malnutrition due to protein-energy wasting, Therefore, assessment of nutritional status should be part of the routine care of dialysis patients.

Methods. We studied 33 clinically stable MHD patients (25 M and 8 F), aged 41 to 88 years (mean 67 years), dialysis vintage 0.02 to 17 years (mean 3 years), treated with once, twice, or trice weekly dialysis sessions. Body composition was assessed by means of electrical body impedance (BIA) using a single frequency analyzer, resistance, reactance and phase angle (PA) values were registered and body cell mass (BCM) and fat-mass (FM) were calculated. For comparison, mid arm triceps and biceps skinfold thickness were measured with a skin-fold caliper to estimate subcutaneous fat. Middle arm muscle area (MAMA) was calculated from middle arm circumference (MAC) and skinfold thickness. Waist and hip circumference were measured. All the measurements were taken at the end of the midweek dialysis session. Serum creatinine and urea were measured before and at the end of the dialysis session. As reference for the measurement of muscle mass, creatinine index (mg/24 hours) was calculated adding to creatinine generation the extra-renal creatinine metabolism and, in patients with residual renal function, the urinary excretion of creatinine.

Results. The creatinine index was significantly correlated with BCM (p<0.000003), PA (p<0.00002), MAMA (p<0.008) and MAC (p<0.02). FM calculated from BIA was significantly correlated with waist (p<0.000001) and hip (p<0.000001) circumference and with subcutaneous fat thickness (p<0.00000). MAMA was highly correlated with MAC (p<0.000001), with BCM (p<0.00006), and PA (p<0.004). It is possible an adequate evaluation of nutritional status by the BCM, FM, and PA values, obtained with BIA. Furthermore, our results indicate that it is possible to evaluate body composition, and in particular subcutaneous fat and muscle mass, by means of very simple and cheap anthropometric methods.

Conclusion. Anthropometric measurement of subcutaneous fat and middle arm muscle area allow the asssessment on nutritional status in maintenance hemodialysis patients.