Masked uncontrolled hypertension in patients on maintenance hemodialysis

Masked uncontrolled hypertension (MUCH) has been proven to be associated with increased cardiovascular risk in the general population. We performed the current analysis to determine its prevalence in dialysis patients and its association with pulse wave velocity (PWV). From 368 participants of another cohort study, we selected 145 subjects with controlled predialysis blood pressure (BP). All subjects underwent ambulatory BP monitoring and PWV measurement. MUCH was defined as controlled predialysis BP with daytime BP. 135/85 mm Hg (definition-1); total ambulatory BP. 130/80 mm Hg (definition-2); and either daytime BP. 135/85 mm Hg or nighttime BP. 120/70 mm Hg (definition-3). The prevalence of MUCH was 43.4% (definition-1), 55.9% (definition-2) and 74.5% (definition-3). Multivariable logistic regression analysis showed that the use of antihypertensive medication was the most consistent predictor of MUCH within all 3 definitions (all odds ratio (OR)>= 4.28, P<0.001). Predialysis systolic BP (both OR41, P<0.04), predialysis diastolic BP (both OR=41, P<0.001) and hemoglobin (both ORo1, P=0.02) were all significantly associated with MUCH in two models. Interdialytic weight gain (OR=0.52, P=0.02) was associated with MUCH under definition-2, and BMI (OR=0.86, P=0.03) was associated with MUCH under definition-3. Patients with MUCH had significantly elevated PWV compared with their counterparts according to all three definitions with or without adjusting for covariates (all P <= 0.03). In conclusion, MUCH affects a large proportion of dialysis patients with controlled predialysis BP and is associated with increased PWV. Patients on antihypertensive medications and with higher predialysis BP are more likely to have MUCH.