20 Aug Chronic Kidney Disease: Blood Pressure and Mortality
MedicalResearch.com Interview with:
Dr.Csaba P. Kovesdy MD FASN.
The Fred Hatch Professor of Medicine
Director, Clinical Outcomes and Clinical Trials Program in Nephrology
University of Tennessee Health Science Center
Chief of Nephrology
Division of Nephrology, Memphis VA Medical Center
MedicalResearch.com: What are the main findings of the study?
Dr. Kovesdy: In this study of >650,000 US veterans with CKD we found that categories of lower SBP/DBP combinations are associated with lower mortality only as long as the DBP component remains above a threshold of approximately 70 mmHg, and that patients with BP values in the range of 130-159/70-89 mmHg had the lowest mortality. Patients who might be considered to have “ideal” blood pressure (<130/80) actually had increased mortality due to the inclusion of individuals with low systolic and diastolic blood pressures.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Kovesdy: The most surprising finding of our study is that when considering SBP and DBP together in the same patient a low DBP seems to “trump” the effects of a high SBP, and patients with ideal DBP and elevated SBP had better outcomes than patients with ideal SBP and low DBP. This finding may have therapeutic implications, since treating an elevated SBP in a patient with isolated systolic hypertension is a common practical scenario.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Kovesdy: Current guidelines advocate treatment of only elevated blood pressure, and ignore the potential dangers of over-treatment.
Patients with CKD are considered to be a high-risk category, and hence even stricter blood pressure targets are advocated in them. Our findings go against this notion, since we found that low blood pressures can also be associated with increased mortality. Caution is advised, especially in patients who present with a high SBP combined with a low DBP.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Kovesdy: It will be necessary to test these findings in a clinical trial, since the observational nature of our study only allows us to establish associations, but causality cannot be implied.
Csaba P. Kovesdy, MD; Anthony J. Bleyer, MD; Miklos Z. Molnar, MD, PhD; Jennie Z. Ma, PhD; John J. Sim, MD; William C. Cushman, MD; L. Darryl Quarles, MD; and Kamyar Kalantar-Zadeh, MD, PhDAnn Intern Med. 2013;159(4):233 doi:10.7326/0003-4819-159-4-201308200-00004