[Nutritional status, comorbidity, and inflammation in hemodialysis]

Low y serum albumin and high C-reactive protein (CRP) have been shown to be significant predictors of mortality in hemodialysis (HD) patients. Although hypoalbuminemia has been attributed to malnutrition, it has recently been recognized evidence of inflammation that predicts serum albumin concentration in dialysis patients.

To establish, in our HD patients, the factors associated with malnutrition, hypoalbuminemia and elevated levels of C-reactive protein to determine its influence in the incidence and cause of death during a one year follow-up period.

A cross sectional study was performed in 64 patients (35 males, 13% diabetics; mean age 64 +/- 12), who had beep on HD for 64 +/- 58 months. We assessed nutritional status by anthropometric and biochemical parameters and estimated protein and calorie intake by diet recall. The dialysis dose was measure by KT/V normalized for actual and ideal body weight (BW). Comorbidity (total and cardiovascular) were measured using a modified M. Charlson index. CRP was used as a marker of inflammation. During a one year follow-up period we determined the incidence and cause of death.

According to Bilbrey index only seven patients (11%) were well nourished. The variables associated with malnutrition were civil status (not married) and dialysis dose estimated by KT/V normalized to ideal BW. Serum albumin (mean 4.1 +/- 0.3 g/dl) was associated with creatinine, comorbidity age and infection. 37.5% of the patients had CRP > 1 mg/dl and they had more cardiovascular comorbidity and lower serum albumin, and they used higher doses of erythropoietin (table III). Patients using modified cellulosic membranes had higher levels of CRP. Multivariate analysis showed that high global comorbidity, low serum cholesterol, and high level of CRP and hematocrit predicted death. The principal cause of mortality was infection.

Malnutrition is a common problem in HD patients. Low dialysis dose is associated with malnutrition in some patients. We propose to normalize urea clearances to ideal body weight. Inflammatory activity is frequent in HD, probably as a result of intermittent activation of the acute phase response during the dialysis procedure. Low serum albumin in HD patients is principally associated with infection/inflammation but not with malnutrition. CRP is a sensitive marker of inflammation and an power predictor of mortality in HD patients.