The impact of malnutrition in morbidity and mortality in stable haemodialysis patients

Abstract

BACKGROUND: When assessed by single biochemical measurements, malnutrition in dialysis patients is associated with increased mortality, but there are few data evaluating abnormalities in anthropometry or composite nutritional scores and outcome. The aim of our study was to ascertain the prevalence and severity of malnutrition in 761 stable patients from 20 haemodialysis centres and its influence in morbidity and mortality after one year of follow-up. METHODS: Malnutrition was estimated by scoring four anthropometric indexes; body mass index (BMI), triceps skinfold thickness (TSF), mid-arm circumference (MAC), and mid-arm muscle circumference (MAMC); three biochemical measurements; serum albumin, serum transferrin and total lymphocyte count; and clinical examination. Mortality and hospitalizations were collected prospectively during the year of follow-up. RESULTS: A moderate/severe degree of malnutrition was presented by 51.6% of male and 46.3% of female patients. TSF was moderate-severely decreased in 41% without differences between males and females. MAMC was moderately decreased in 19.8% of males and in 8.1% of females (P < 0.001). Multiple logistic regression analysis showed that the predictors of malnutrition were: age > 65 years (OR = 1.96, CI: 1.22-3.14), male sex (OR = 1.95, CI: 1.24-3.07), comorbidity index (OR = 1.23, CI: 1.03-1.45), time on dialysis (OR = 1.13, CI: 1.08-1.18), duration of dialysis (OR = 0.73, CI: 0.63-0.85) and PCR related to ideal body weight (OR = 0.17, CI: 0.06-0.50). After 1 year of follow-up, data from 442 patients were available. A total of 68 patients died (15.4%) with cardiovascular diseases being the most frequent cause of death (57.3% of the cases). The predictors of mortality were: age (OR = 1.06, CI: 1.03-1.09), cardiovascular disease (OR = 2.13, CI: 1.19-3.83), neurological disease (OR = 2.96, CI: 1.41-6.15), nephroangiosclerosis (OR = 2.34, CI: 1.10-4.98) and total lymphocyte count (OR = 0.93, CI: 0.87-0.98). Hospitalization was needed in 44% of patients. The comorbidity index, serum albumin and age were the predictive factors of hospitalization. CONCLUSIONS: Protein-calorie malnutrition is frequent in haemodialysis patients. Fat depletion predominated in both sexes. Duration of dialysis and protein catabolic rate related to ideal body weight was the only predictor which could be influenced by a nutritional intervention. Morbidity appeared to be influenced by the comorbidity index and age was the strongest predictor of mortality. The only nutritional measurements predictive of morbidity and mortality were serum albumin and total lymphocyte count respectively. Therefore, the influence of malnutrition in morbidity and mortality can not be definitively stated.