Hyperhomocysteinemia, nutritional status, and cardiovascular disease in hemodialysis patients

Background Hyperhomocysteinemia, cardiovascular disease (CVD), and malnutri tion are common in patients with endstage renal disease (ESRD). This study was designed to assess possible relationships between total plasma homocyst eine (tHcy), nutritional status, and ischemic CVD. Methods. We performed a cross-sectional study in 117 unselected patients on maintenance hemodialysis (HD) treatment, among whom there was a high preva lence of malnutrition (56%), as assessed by the subjective global nutrition al assessment (SGNA), and a high prevalence of CVD (60%), and prospectively , we followed-up the overall mortality for four years. Results. The level of tHcy was elevated in 95% of the HD patients, and that of total plasma cysteine (tCys) was also significantly elevated, while the plasma concentrations of methionine (Met), serine (Ser), and taurine (Tau) were significantly lower than those in healthy controls. The 65 patients w ho were malnourished according to the SGNA score had significantly lower le vels of serum albumin (S-Alb), plasma IFG-1 (p-IGF-1), tHcy, tCys, and Met than the 52 patients with normal nutritional status, whereas the levels of Ser, Tau, plasma folate, and vitamin B-12 were similar in the two groups. T he prevalence of malnutrition was 30 % in the 47 patients without CVD and w as significantly higher (70%, P < 0.001) in the 70 patients with CVD, who a lso had lower tHcy, S-Alb, plasma IGF-1, serum creatinine (S-Cr), and blood hemoglobin. The tHcy levels were positively correlated with S-Alb, Met, tC ys, and S-Cr Stepwise, multiple-regression analysis showed that tCys, S-Alb , and normalized protein equivalent of nitrogen appearance (nPNA), an indic ator of protein intake, were independent predictors of tHcy. The patients w ith tHcy <24 mu mol/L (median value) had a significantly worse four-year su rvival than those with a higher tHcy (greater than or equal to 24 mu mol/L) . Conclusions. Our results demonstrate that most of HD patients have grossly elevated tHcy levels, but that the absolute level appears to be dependent o n nutritional status, protein intake, and S-Alb The results also suggest th at the lower tHcy levels in patients with CVD than in those without CVD may be related to the higher prevalence of malnutrition and hypoalbuminemia in the CVD patients. This is also in accordance with our observation that the patients with lower tHcy had a worse survival rate than those with higher tHcy, considering that malnutrition is a strong risk factor for mortality a nd that CVD is the most common cause of death in ESRD patients.