Malnutrition and Chronic Inflammation as Risk Factors for Cardiovascular Disease in Chronic Renal Failure

Immune activation in patients with chronic heart failure may be secondary to endotoxin (lipopolysaccharide) action. We investigated the hypothesis that altered gut permeability with bacterial translocation and endotoxaemia would be increased in patients with oedema secondary to congestive heart failure. We compared 20 patients who had chronic heart failure with recent-onset peripheral oedema (mean age 64 years [SD 10], New York Heart Association [NYHA] class 3.3 [0.7]), 20 stable non-oedematous patients with chronic heart failure (mean age 63 years [19], NYHA class 2.6 [0.7]), and 14 healthy volunteers (mean age 55 years [16]). Biochemical markers of endotoxaemia, inflammation, and immune activation were measured. Ten patients were studied within 1 week of complete resolution of oedema. Five patients survived longer than 6 months and were restudied again after remaining free of oedema for more than 3 months. Mean endotoxin concentrations were higher in oedematous patients with chronic heart failure than in stable patients with chronic heart failure (0.74 [SD 0.45] vs 0.37 EU/mL [0.23], p=0.0009) and controls (0.46 EU/mL [0.21], p=0.02). Oedematous patients had the highest concentrations of several cytokines. After short-term diuretic treatment, endotoxin concentrations decreased from 0.84 EU/mL [0.49] to 0.45 EU/mL [0.21], p<0.05) but cytokines remained raised. After freedom of oedema for more than 3 months after oedema resolved, endotoxin concentrations remained unchanged from the previous visit (0.49 EU/mL [0.06], p=0.45). Raised concentrations of endotoxin and cytokines are found in patients with chronic heart failure during acute oedematous exacerbation. Intensified diuretic treatment can normalise endotoxin concentrations. Our preliminary findings suggest that endotoxin may trigger immune activation in patients with chronic heart failure during oedematous episodes.

Signs of protein-energy malnutrition are common in maintenance hemodialysis (HD) patients and are associated with increased morbidity and mortality. To evaluate the nutritional status and relationship between various parameters used for assessing malnutrition, we performed a cross-sectional study in 128 unselected patients treated with hemodialysis (HD) thrice weekly for at least two weeks. Global nutritional status was evaluated by the subjective global nutritional assessment (SGNA). Body weight, skinfold thicknesses converted into % body fat mass (BFM), mid-arm muscle circumference, hand-grip strength and several laboratory values, including serum albumin (SA1b), plasma insulin-like growth factor I (p-IGF-I), serum C-reactive protein (SCRP) and plasma free amino acids, were recorded. Dose of dialysis and protein equivalence of nitrogen appearance (nPNA) were evaluated by urea kinetic modeling. The patients were subdivided into three groups based on SGNA: group I, normal nutritional status (36%); group II, mild malnutrition (51%); and group III, moderate or (in 2 cases) severe malnutrition (13%). Clinical factors associated with malnutrition were: high age, presence of cardiovascular disease and diabetes mellitus. nPNA and Kt/V(urea) were similar in the three groups. However, when normalized to desirable body wt, both were lower in groups II and III than in group I. Anthropometric factors associated with malnutrition were low body wt, skinfold thickness, mid-arm muscle circumference (MAMC), and handgrip strength. Biochemical factors associated with malnutrition were low serum levels of albumin and creatinine and low plasma levels of insulin-like growth factor 1 (IGF-1) and branched-chain amino acids (isoleucine, leucine and valine). The serum albumin (SAlb) level was not only a predictor of nutritional status, but was independently influenced by age, sex and SCRP. Plasma IGF-1 levels also reflected the presence and severity of malnutrition and appeared to be more closely associated than SAlb with anthropometric and biochemical indices of somatic protein mass. Elevated SCRP (> 20 mg/liter), which mainly reflected the presence of infection/inflammation and was associated with hypoalbuminemia, was more common in malnourished patients than in patients with normal nutritional status, and also more common in elderly than in younger patients. Plasma amino acid levels, with the possible exception of the branched-chain amino acids (isoleucine, leucine, valine), seem to be poor predictors of nutritional status in hemodialysis patients.