The pathogenesis of hypertension is multifactorial in patients with chronic kidney disease (CKD). We explored the relative contribution of arterial stiffness and fluid overload to blood pressure (BP) in these patients. We evaluated 1531 patients from a prospective observational cohort study of high-risk patients with cardiovascular disease. BP, arterial stiffness, and volume status expressed as the extracellular water/total body water ratio (ECW/TBW) were measured by 24-h BP monitoring, pulse-wave velocity (PWV), and bioelectrical impedance analysis, respectively. Multiple linear regression analysis showed that both PWV and ECW/TBW of the patients with CKD were significantly associated with 24-h systolic BP (SBP). The areas under the receiver-operating characteristic curve (AUCs) for predicting 24-h SBP ≥130 mm Hg significantly increased after PWV was added to conventional factors regardless of CKD status. However, the AUCs did not increase in the ECW/TBW-based models. When a cut-off 24-h SBP level of 140 mm Hg was used, the predictability of ECW/TBW for elevated BP significantly improved in patients with CKD (0.718 vs. 0.683, P = 0.034) but not in those without. Notably, a significant impact of arterial stiffness on high BP was consistently observed regardless of CKD status. This association was further confirmed by the net reclassification and integrated discriminant improvements, root mean squared error with adjusted R 2 , and interaction effects. As kidney function declines, fluid overload is significantly associated with high BP. The impact of fluid overload on BP is only observed in more severe hypertension in patients with CKD.
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Acknowledgements Grant support: This research was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute funded by the Ministry of Health & Welfare, Republic of Korea (grant no. HI13C0715) and by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning (NRF-2015R1A2A2A01007346).
All Science Journal Classification (ASJC) codes
- Internal Medicine
- Cardiology and Cardiovascular Medicine