Changes of pulse wave velocity findings and the effects of folic acid treatment on homocysteine levels in End Stage Renal Disease

Koh, Jae Ki; Kim, Su Hyun; Shin, Suk Ho; Chun, Kwan Sun; Choi, Jun Hyouck; Lim, Ji Hwan; Yoon, Su Jin

Abstract

BACKGROUDN: In end-stage renal disease (ESRD) patients, cardiovascular disease (CVD) is a major cause of morbidity and mortality. These patients frequently have hyperhomocysteinemia, a putative risk factor for cardiovascular disease. Several studies suggest that lowering plasma homocysteine may improve endothelial dysfunction, a marker of atherothrombotic risk. Pulse wave velocity (PWV) is a useful diagnostic tool to access endothelial dysfunction, and is widely used screening test for atherosclerosis.
METHODS
We measured fasting total plasma homocysteine (tHcy) in 84 hemodialysis patients and 21 peritoneal dialysis patients. Subjects were assigned to two groups. Group I (tHcy <20 umol/L) consisted of 74 ESRD patients who have taken continual usual dose folate (1 mg/day). Group II (tHcy> or =20 umol/L) consisted of 26 ESRD patients who have taken high dose folate (5 mg/day). For 15 Group I patients and 5 Group II patients, pulse wave doppler velocity (PWV) measurements were taken before and after 3 months of folate treatment.
RESULTS
The mean tHcy concentration was higher in the ESRD patients (82 HD: 16.9+/-6.4 mol/L, 20 PD: 18.0+/-16.7 mol/L). The pulse wave velocity (PWV) was faster in ESRD patients-19 HD: Aorta (Ao)-PWV 8.98+/-1.4, lower extremities (LE)-PWV 10.15+/-1.3, upper extremities (UE)-PWV 8.80+/-0.8 (m/s); 8 PD: Ao-PWV 9.32+/-1.8, LE-PWV 10.64+/-1.4, UE-PWV 9.24+/-0.7 (m/s). The PWV increased in ESRD patients with coronary heart disease and who had a history of angioplasty because of thrombosis or stenosis of vascular access. There was a significant reduction in hyperhomocysteinemia after 3 months in the high dose folate supplement group as compared to the usual dose folate supplement group with a significant statistical difference between the two groups. (15 Group I patients: 13.9+/-4.9 mol/L->13.5+/-6.1 for 5 Group II patients: 34.3+/-27.5 mol/L->23.0+/-5.9 mol/L (p<0.05, paired t-test). No difference in the PWV was found before and after folic acid supplementation for the two groups (p>0.05, paired t-test).
CONCLUSIONS
We assume that PWV and homocysteine concentration have some correlation and both studies are available as part of screening tests for atherosclerosis in ESRD. Although no significant interval change was detected for the PWV, this finding suggests that high-dose folate supplementation was helpful to minimize the risk of cardiovascular disease associated with hyperhomocysteinemia in ESRD patients.