6 The Most Important Factor for Cardiovascular Morbidity in Hemodialysis Patients is Microinflammation

Abstract

In hemodialysis (HD) patients, cardiovascular (CV) morbidity is 10 to 20 times higher than in the general population. Dyslipidemia, malnutrition, and non‐traditional CV risk factors are well‐known important determinants in the increased CV morbidity. We therefore measured levels of serum high‐sensitivity C‐reactive protein (CRP), interleukin 6 (IL‐6), tumor necrosis factor‐α (TNF‐α), albumin, ferritin, cholesterol (CHOL), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), lipoprotein(a) (Lpa) and body mass index (BMI) in 22 HD patients (age 62.8 ± 12.8) on maintenance HD for 65.16 ± 33 months. All patients received standard dietary guidance with an average protein intake of 1.2 g/kg/day, 35 kcal/kg, phosphate and potassium restriction. Twenty of 22 patients had well treated high blood pressure. Two patients had non‐insulin‐dependent diabetes mellitus treated only with diet. The patients were not treated with lipid lowering drugs, and only one patient was a smoker.The mean values of serum CHOL (4.31 ± 0.88 mmol/L), TG (1.77 ± 1.1 mmol/L), HDL (1.09 ± 0.35 mmol/L) and LDL (2.43 ± 0.53 mmol/L) were normal. The patients had elevated values of serum CRP (10.63 ± 12.56 mg/L), IL‐6 (1.49 ± 1.66 pg/mL), TNF‐α (7.26 ± 5.52 pg/mL) and Lpa (0.17 ± 0.15 µg/dL). The mean value of serum albumin (41.03 ± 2.38 g/L) was also normal; the mean value of BMI (26.32 ± 4.34 kg/m2) was mildly elevated. The patients had elevated serum ferritin (518 ± 342 mmol/L), but within the expected range. The mean value of Kt/V (1.86 ± 0.23) was high normal.Our patients have elevated CRP, IL‐6 and TNF‐α. In contrast with other studies our patients had normal lipid status and also normal nutritional status. No significant relationships were found between CRP, IL‐6, TNF‐α, or ferritin and age, history of dialysis, albumin, and BMI. There was only a significant correlation between months on dialysis and HDL (r = −0.46, P = 0.048), but no significant correlation between months on dialysis and albumin, BMI, CHOL, TG, LDL, and Lp(a).We concluded that in our HD patients, the most important factor for high CV morbidity was microinflammation. Dyslipidemia and malnutrition are well controlled in optimally treated HD patients and seems to be only a minor factor for CV morbidity.