The status of blood pressure control and the effect of dialysis adequacy on blood pressure in chronic hemodialysis patients

Koo, Ja Ryong; Kim, Myung Bin; Park, Ky Yong; Kim, Guen Ho; Chun, Rho Won; Kim, Hyung Jik; Chae, Dong Wan; Noh, Jung Woo

Abstract

OBJECTIVE
Volume expansion has been known to be the major factor in the development of hypertenision in chronic hemodialysis(HD) patients. But some HD patients remain hypertensive even with adequate volume control, which suggests the role of undefined uremic toxin in the pathogenesis of hypertension. So we aimed to evaluate the status of blood pressure (BP) control and the effect of Kt/V (as a marker for removal of uremic toxin) on BP in chronic HD patients.
METHODS
The status of BP control was obtained from records of 8 HD session in 132 patients in November 1996 and 127 patients in November 1997. Of 132 patients studied in 1996, 70 patients underwent a follow-up evaluation in 1997. All patients were dialyzed 3 times a week, 4 hours a session. Postdialytic cyclic 3',5' guanosine monophosphate (cGMP) level was measured in 48 patients as a marker of volume status.
RESULTS
The prevalence of postdialytic hypertension (>140/90mmHg) was 73.5 in 1996 and 65.3% in 1997. Normotensive patients (postdialytic mean BP<114 mmHg) had higher Kt/V value than hypertensive patients in both 1996 and 1997. But there was no difference in the degree of ultrafiltration (UF) and cGMP level between two groups. Postdialytic mean BP was inversely correlated with Kt/V level but had no relationship with degree of UF and cGMP level in both 1996 and 1997. The group in which postdialytic mean BP had been decreased during 1 year study period had higher degree of elevation in Kt/V than the group in which postdialytic mean BP had been increased. The changes of postdialytic weight and degree of UF during study period were similar between two groups. The number of antihypertensives used were also inversely correlated with Kt/V but not correlated with degree of UF and cGMP level in both 1996 and 1997.
CONCLUSION
Our study indicate that increasing HD adequacy is associated with improved control of postdialytic mean BP and less use of antihypertensive drugs. UF and antihypertensive drugs may not be adequate form of hypertension treatment as once thought and increasing HD adequacy can be an alternative method.