Hyperhomocystinemia and the prevalence of symptomatic atherosclerotic vascular disease in Taiwanese chronic hemodialysis patients: a retrospective study

Abstract

Aim: Hyperhomocystinemia is now recognized as an independent risk factor for atherosclerotic cardiovascular disease in patients with normal renal function. Hyperhomocystinemia is common in patients with chronic renal failure. This aim of this study was designed to look for associations between hyperhomocystinemia and clinically symptomatic atherosclerotic vascular disease (ASVD) in Taiwanese chronic hemodialysis patients.

Methods: Two hundred patients undergoing hemodialysis were enrolled in the study. They had predialysis blood work performed for total homocysteine, serum folate, and vitamin B12 levels. A history of clinically significant ASVD was elicited using information from the patients' questionnaires and verified by careful inpatient and outpatient chart review.

Results: Mean homocysteine concentration was 29.0 micromol/L overall. A total of 196 patients had hyperhomocystinemia and were enrolled in this study. ASVD was present in 24.5% of patients. The mean homocysteine concentration was 31.9 micromol/L and 28.7 micromol/L in patients with (n = 48) and without (n = 148) ASVD, respectively (P = 0.04). There was association hyperhomocystinemia between chronic hemodialysis patients with ASVD and without ASVD. There were significant differences including age, homocysteine level, vitamin B12 level and glucose intolerance in the two groups (P < 0.05). Plasma homocysteine concentrations showed significant positive correlations with serum folate or vitamin B12 in majority patients. No patient had serum folate or vitamin B12 deficiency. The adjusted odds ratio for atherosclerotic disease was 2.8 (95% CI, 1.109-7.467) for those subjects with a homocysteine level in the highest quartile compared with the lowest 3 quartiles.

Conclusions: The prevalence of hyperhomocystinemia is 98% among hemodialysis patients. There is a significant association between hyperhomocystinemia and ASVD in Taiwanese chronic hemodialysis patients. There are also associations between homocysteine levels and serum folate/vitamin B12 levels in the majority of the patients. Clinical trials are needed to determine the optimal therapy of folic acid dose for hyperhomocystinemia in Taiwanese chronic hemodialysis patients in the future.