This Article Full Text Full Text (PDF) All Versions of this Article: 50/1/143    most recent HYPERTENSIONAHA.107.091579v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kelley, K. Articles by Agarwal, R. Search for Related Content PubMed PubMed Citation Articles by Kelley, K. Articles by Agarwal, R. Related Collections Clinical Studies Other diagnostic testing

(Hypertension. 2007;50:143.)
© 2007 American Heart Association, Inc.

Original Articles

Trended Cosinor Change Model for Analyzing Hemodynamic Rhythm Patterns in Hemodialysis Patients

From the Inquiry Methodology Program (K.K.), Indiana University, Bloomington; Division of Nephrology (R.P.L., R.A.), Department of Medicine, Indiana University School of Medicine, Indianapolis; and Richard L. Roudebush VA Medical Center (R.P.L., R.A.), Indianapolis, Ind.

Correspondence to Rajiv Agarwal, VA Medical Center, 111N, 1481 West 10th St, Indianapolis IN 46202. E-mail ragarwal{at}iupui.edu

To describe circadian blood pressure (BP) patterns and linear interdialytic changes, a model was developed to describe simultaneously both the straight line change and oscillatory variation in BP and heart rate over an interdialytic interval in hemodialysis patients. Using this trended cosinor model, we simultaneously compared the impact of mean level of BP, linear changes over the interdialytic interval, and oscillatory changes in BP and its relationship with antihypertensive drug use. Neither a straight-line change model nor the cosinor model adequately described the BP variability in 12 750 BP measurements from 136 chronic stable hemodialysis patients. A combination of the 2 models that allowed for the oscillatory rhythmic pattern in BP variation to have an upward trend in the interdialytic period most accurately described the data. Time elapsed since the end of dialysis demonstrated a better model fit compared with the less meaningful clock time. More antihypertensive medication use was associated with increasing mean systolic, diastolic, and pulse pressure. Although the rate of change was blunted with increasing antihypertensive drug use, the impact on oscillatory change was U-shaped for systolic BP, direct for diastolic BP, and inverse for pulse pressure. A trended cosinor model better describes the change in BP in the interdialytic interval in hemodialysis patients, especially when time elapsed is measured from the end of dialysis. Antihypertensive drugs, though associated with higher average BP, are associated with blunted rate of change in BP over time.

Key Words: hemodialysis • hypertension • ambulatory blood pressure monitoring • circadian rhythms • statistical modeling

This article has been cited by other articles:

				R. Agarwal and R. P. Light GFR, proteinuria and circadian blood pressure Nephrol. Dial. Transplant., August 1, 2009; 24(8): 2400 - 2406. [Abstract] [Full Text] [PDF]

				R. Agarwal Volume-Associated Ambulatory Blood Pressure Patterns in Hemodialysis Patients Hypertension, August 1, 2009; 54(2): 241 - 247. [Abstract] [Full Text] [PDF]

				R. Agarwal, T. Metiku, G. G. Tegegne, R. P. Light, Z. Bunaye, D. M. Bekele, and K. Kelley Diagnosing Hypertension by Intradialytic Blood Pressure Recordings Clin. J. Am. Soc. Nephrol., September 1, 2008; 3(5): 1364 - 1372. [Abstract] [Full Text] [PDF]

				R. Agarwal and R. P. Light Arterial stiffness and interdialytic weight gain influence ambulatory blood pressure patterns in hemodialysis patients Am J Physiol Renal Physiol, February 1, 2008; 294(2): F303 - F308. [Abstract] [Full Text] [PDF]