Time points for obtaining representative values of 24-hour blood pressure in chronic kidney disease.
OBJECTIVE
Ambulatory blood pressure (BP) monitoring has been widely recommended for evaluating the status of BP, but is lacking in practicality. Determination of the specific time points for BP measurement that are representative of 24-hour mean BP could be useful and convenient in hypertensive patients with chronic kidney disease (CKD).


METHODS
A total of 1,317 patients for whom 24-hour ambulatory BP monitoring was performed were enrolled in a multicenter study on hypertensive CKD. We analyzed the time points at which systolic blood pressure (SBP) values exhibited the smallest differences from 24-hour mean SBP (mSBP). We included office mSBP and analyzed the relationships between SBPs at the office and the time points with the smallest differences from 24-hour mSBP using several methods.


RESULTS
The time points with the smallest differences from 24-hour mSBP were 7:00 AM, 2:00 PM, and 9:30 PM. In regression analysis, SBPs at 7:00 AM and 9:30 PM were better correlated with 24-hour mSBP than SBPs at 2:00 PM and the office. The proportions of patients with SBPs within 30% of 24-hour mSBP were higher at 7:00 AM and 9:30 PM. The best consistency between the uncontrolled hypertensive groups, defined as ≥ 135 mmHg of 24-hour mSBP and higher values of SBPs corresponding to 135 mmHg of 24-hour mSBP, were observed at the 7:00 AM and 9:30 PM time points.


CONCLUSIONS
The specific time points for SBPs that correlated well with 24-hour mSBP in hypertensive CKD patients were 7:00 AM and 9:30 PM.
Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
Jiwon
J
Ryu
Department of Internal Medicine, National Medical Center, Seoul, Korea.
Ran-hui
RH
Cha
Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
Dong Ki
DK
Kim
Medical Research Collaborating Center, Seoul National University Bundang Hospital, Seongnam, Korea.
Ju Hyun
JH
Lee
Department of Internal Medicine, College of Medicine, Uijeongbu St. Mary's Hospital, The Catholic University of Korea, Uijeongbu, Korea.
Sun Ae
SA
Yoon
Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
Dong Ryeol
DR
Ryu
Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea.
Jieun
J
Oh
Medical Research Collaborating Center, Seoul National University Bundang Hospital, Seongnam, Korea.|Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
Sejoong
S
Kim
Department of Internal Medicine, Inje University College of Medicine, Goyang, Korea.
Sang-Youb
SY
Han
Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan, Korea.
Eun Young
EY
Lee
Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
Yon Su
YS
Kim
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D002940:Circadian Rhythm; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009819:Office Visits; D011237:Predictive Value of Tests; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis* / Q000503:physiopathology; D056910:Republic of Korea; D013997:Time Factors; D055815:Young Adult
Ambulatory blood pressure measurement; Blood pressure measurement; Chronic kidney disease; Hypertension; Timing for representative blood pressure