The Association Between Malnutrition, Inflammation and Atherosclerosis in Hemodialysis Patients
Introduction and Aims: A syndrome linking malnutrition, inflammation and atherosclerosis (MIA syndrome) has been described in haemodialysis (HD) patients and assumed to underlie the strikingly high cardiovascular morbidity and mortality in them. However, the exact underlying mechanisms remain to be determined. This work evaluates some indices of inflammation and malnutrition in HD patients and correlates them with serum levels of some proinflammatory cytokines and clinical evidence of
Subjects and Methods: Fifty non- smoker end- stage renal disease (ESRD) patients maintained on regular HD for > 6 months were studied. None had diabetes, connective tissue disease or evident acute infection. Age and sex matching 26 healthy subjects were included as controls. All subjects were evaluated for clinical and electrocardiographic evidence of atherosclerotic vascular disease. Nutritional status was assessed by body mass index (BMI), triceps skin fold (TSF), mid-arm circumference (MAC), mid-arm muscle circumference (MAMC), total body fat (TBF) and fat free mass (FFM). Carotid ultrasonography (US) was used for detection of atheromatous plaques and measurement of intima-media thickness (IMT). Laboratory investigations included serum lipid profile, albumin, prealbumin, high sensitivity C- reactive protein (CRP), ? 1 acid glycoprotein (? 1AGP) and some proinflammatory cytokines, namely, interleukin- 1? (IL-1? ), IL-6 and tumour necrosis factor- ? (TNF-? ). The
prognostic inflammatory and nutritional index (PINI) was calculated [(CRP) X (? 1AGP)] / [(albumin) X (prealbumin)].
Results:Clinical evidence of atherosclerosis occurred in 30% of patients (15). Male patients had significantly lower MAC, MAMC and FFM compared with male controls. atients collectively had significantly higher IMT, serum CRP, ? 1AGP, PINI, IL-6, TNF-? and significantly lower serum total cholesterol, HDL-C, albumin and prealbumin ompared to controls. Serum albumin correlated negatively with IL-6. Serum CRP correlated positively with carotid IMT.
Conclusion: Maintenance HD patients suffer an inflammatory state which is closely linked to parameters of malnutrition and atherosclerosis. Calculation of PINI provides a sensitive marker to follow up the presence and extent of both inflammation and malnutrition in HD patients. Interventions aimed to improve nutritional status and limit exposure to inciting agents of inflammation would help to reduce cardiovascular disease (CVD) morbidity and mortality in these patients.
Key words: malnutrition, inflammation, atherosclerosis, haemodialysis, proinflammatory cytokines.