Blood pressure and survival in long-term hemodialysis patients with and without polycystic kidney disease

Abstract

Background In maintenance dialysis patients, low blood pressure (BP) values are associated with higher death rates when compared to normal to moderately high values. This “hypertension paradox” may be related to comorbid conditions. Dialysis patients with polycystic kidney disease (PKD) usually have a lower comorbidity burden and greater survival. We hypothesized that in PKD dialysis patients, a representative of a healthier dialysis patient population, high BP is associated with higher mortality. Methods Time-dependent survival models including after multivariate adjustment were examined to assess the association between pre- and post-hemodialysis BP and all-cause mortality in a 5-year cohort of 67,085 non-PKD and 1,579 PKD hemodialysis patients. Results In PKD patients low pre- and post-hemodialysis systolic BPs were associated with increased mortality, whereas high pre-hemodialysis diastolic BP was associated with greater survival. Fully adjusted death hazard ratios (and 95% confidence levels) for pre- and post-hemodialysis BP of <120 (reference: 140-<160 mmHg) were 1.30 (1.06-1.92) and 1.45 (1.04-2.02), respectively, and for pre-hemodialysis diastolic BP of >=80 (reference: 70-<80 mmHg) was 0.68 (0.49-0.93, all p-values <0.05). Similar associations were observed in non-PKD patients. In pooled analyses, within each commensurate BP stratum, PKD patients exhibited superior survival to non-PKD patients. Conclusions Among hemodialysis patients, those with PKD display a similar BP paradox as without PKD, even though within each BP category PKD patients maintain superior survival. Randomized clinical trials are needed to define optimal blood pressure targets in the haemodialysis population.

Transition of care from pre-dialysis prelude to renal replacement therapy: the blueprints of emerging research in advanced chronic kidney disease

“…tertiles) of eGFR slope groups using KaplanMeier curves and unadjusted conditional Cox regression models. For each PS-matched analysis, several 'doubly robust' adjustment levels can be examined including minimally adjusted and case-mix adjusted models, as well as more comprehensive adjustment such as inclusion of laboratory and comorbidity status, as we have done in our recent studies [33,[56][57][58][59][60][61][62][63]. The PS method can primarily be used to account for confounding effects arising from differences in clinical characteristics of patients in whom transition to RRT occurs at different levels of eGFR.…”

The Obesity Paradox and Mortality Associated With Surrogates of Body Size and Muscle Mass in Patients Receiving Hemodialysis

“…2 Whereas obesity is a risk factor for CKD, 3 many epidemiological studies have indicated inverse associations between obesity or other cardiovascular risk factors and mortality in patients with CKD or cardiac disease. 4,5 A higher death rate has been observed in patients with CKD who have a low, rather than a high, body mass index (BMI [calculated as the weight in kilograms divided by height in meters squared]), 6 blood pressure, 7 or serum concentrations of cholesterol 8 or homocysteine, 9 whereas high values of these risk factors are associated with improved survival. Other patient populations, including those with heart failure, 10 those with coronary artery disease, 5,11 and those of advanced age, 12 also exhibit this so-called obesity paradox.…”

Dialysis Modality and Outcomes in Kidney Transplant Recipients

“…The creation of the national DaVita dialysis patient cohort has been described previously (15)(16)(17)(18)(19)(20)(21)(22). Demographic data and details of medical history were collected, with information on age, sex, race, type of insurance, marital status, presence of diabetes, height, body weight (to calculate averaged body mass index), dialysis modality (HD versus PD), and dialysis vintage.…”