title: Renal function exerts only a minor influence on high plasma homocysteine concentrations in patients with acute coronary syndromes.
abstract: It has been suggested that hyperhomocysteinemia observed in patients with occlusive vascular disease is caused by reduced renal function secondary to renovascular disease. We have therefore used serum cystatin C, a new sensitive marker for glomerular filtration, in 59 patients with acute coronary syndromes and high plasma homocysteine (tHcy) concentration to measure renal function. Samples were also obtained from 34 patients with low-normal plasma tHcy and 50 control subjects. The patients with low-normal plasma tHcy concentration showed decreased concentrations of serum cystatin C and serum creatinine and increased concentrations of blood folate and serum cobalamin compared to the controls and to the patients with high plasma tHcy. There was a large overlap in cystatin C concentrations between patients with high and low-normal plasma tHcy. None of the parameters investigated except plasma tHcy were significantly different in the group of patients with high plasma tHcy concentration compared to the control group. In order to further demonstrate the importance of renal impairment, a subgroup of the patients with high plasma tHcy was supplemented daily with folic acid 5 mg, pyridoxine 40 mg and cyancobalamin 1 mg for 3 months. Vitamin therapy reduced plasma tHcy from 18.3+/-4.6 pmol/l to 9.6+/-2.2 pmol/l (p<0.0001). However, vitamin treatment did not strengthen the correlation between cystatin C and plasma tHcy concentrations. These findings do not support the hypothesis that subtle renal dysfunction is an important cause of high plasma tHcy concentration in patients with acute coronary syndromes.
authors.affiliation: Department of Medicine, University of Lund, University Hospital, Sweden. torfi.jonasson@kard.lu.se
authors.forename: Torfi
authors.initials: T
authors.lastname: Jonasson
authors.forename: Hans
authors.initials: H
authors.lastname: Ohlin
authors.forename: Anders
authors.initials: A
authors.lastname: Andersson
authors.forename: Margret
authors.initials: M
authors.lastname: Arnadottir
authors.forename: Björn
authors.initials: B
authors.lastname: Hultberg
mesh_terms: D000208:Acute Disease; D016022:Case-Control Studies; D003327:Coronary Disease / Q000097:blood* / Q000503:physiopathology; D055316:Cystatin C; D015891:Cystatins / Q000097:blood; D005919:Glomerular Filtration Rate; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D014815:Vitamins / Q000008:administration & dosage
chemical_list: C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D014815:Vitamins; D006710:Homocysteine