The Association between Intradialytic Hypertension and Metabolic Disorders in End Stage Renal Disease

BACKGROUND: Intradialytic hypertension was associated with a high mortality risk. We examined the relationship between intradialytic hypertension and metabolic disorders in hemodialysis treatment patients. METHODS: We studied 76 patients in online hemodiafiltration. Dialysis adequacy was defined by Kt/V for urea. Normalized protein catabolic rate (nPCR), as a marker of protein intake, was calculated. Sodium removal was determined as percent sodium removal. Metabolic acidosis was determined by serum bicarbonate less than 22 mmol/L. Interdialytic urine volume more than 100 ml was recorded. Intradialytic hypertension was defined by an increase in systolic blood pressure equal to 10 mmHg from pre- to posthemodialysis. Arterial stiffness was assessed as carotid-femoral pulse wave velocity (c-fPWV) and carotid augmentation index (AIx). Chi-square tests and logistic regression analysis were applied for intradialytic hypertension prediction. RESULTS: Patients with intradialytic hypertension were older and had significantly lower hemoglobin, nPCR, urine output, and serum bicarbonate and significantly higher c-fPWV, though similar Kt/V for urea, than patients without intradialytic hypertension. They also had increased sodium removal and pulse pressure related to less urine output. Serum bicarbonate was inversely associated with c-fPWV (r = −0.377, p = 0.001). Chi-square test showed significant association between intradialytic hypertension and serum bicarbonate < 22 mmol/L (x(2) = 5.6, p = 0.01), which was supported by an adjusted model. CONCLUSION: The intradialytic hypertension was significantly associated with metabolic disorders including malnutrition/inflammation and uncontrolled metabolic acidosis in hemodialysis treatment patients. Severe metabolic acidosis may reflect sodium imbalance and hemodynamic instability of these patients resulting in volume overload and increased vascular resistance.