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Abstract: TH-PO434

Magnitude of the Difference Between Clinic and ABPM BPs Predicts Mortality Risk

Session Information

Category: Hypertension and CVD

  • 1401 Hypertension and CVD: Epidemiology, Risk Factors, and Prevention

Authors

  • Ku, Elaine, University of California, San Francisco, San Francisco, California, United States
  • Hsu, Raymond K., University of California, San Francisco, San Francisco, California, United States
  • Tuot, Delphine S., University of California, San Francisco, San Francisco, California, United States
  • Bae, Se ri, University of California, San Francisco, San Francisco, California, United States
  • Lipkowitz, Michael S., Georgetown University Medical Center , Washington, District of Columbia, United States
  • Grimes, Barbara A., University of California, San Francisco, San Francisco, California, United States
  • Weir, Matthew R., University of Maryland School of Medicine, Baltimore, Maryland, United States
Background

Ambulatory blood pressure (ABP) monitoring is recommended for the detection of masked and white coat hypertension in patients with CKD. Our objective was to determine whether the magnitude of the difference between ambulatory and clinic BP’s has prognostic implications.

Methods

We examined data from 610 participants of the African American Study of Kidney Disease and Hypertension (AASK) Cohort Study, who had completed the AASK Trial and had both clinic BP and ABP performed at Cohort entry. We performed multivariable Cox proportional hazards models to determine the association between absolute systolic BP (SBP) difference between clinic and awake ABPs with death.

Results

Mean age was 61 years, 38% were female, and mean eGFR was 39. During median follow-up of 10 years, 33% died; 30% developed ESRD. The association between the clinic-awake SBP difference and risk of death is shown in Figure1 and Table1. Higher clinic-versus-awake SBP (white coat phenomenon) was associated with higher mortality risk compared to 0-5mm Hg clinic-awake SBP difference. A ≤ -5 mmHg lower clinic-versus-awake SBP (masked phenomenon) was also associated with higher mortality. Additonal adjustment for clinic SBP or ambulatory SBP did not change these findings.

Conclusion

Our data revealed a U-shaped, independent association between the magnitude of the difference between clinic and ambulatory SBP and mortality in black patients with CKD. Further studies are needed to examine whether interventions to lower clinic-ABP differences will improve patient outcomes.

Difference between clinic and mean awake ABP and long-term risk of death
Absolute SBP difference between clinic BP and awake ABPNUnadjusted ModelAdjusted Model*
"White Coat Effect"
≥ 10 mm Hg1042.30 (1.27-4.18)2.31 (1.27-4.22)
5 to <10 mm Hg582.07 (1.07-4.02)1.84 (0.94-3.56)
0 to <5 mm Hg77ReferenceReference
"Masked Effect"
-5 to <0 mm Hg911.04 (0.54-2.02)1.15 (0.59-2.24)
≤ -5 mm Hg2801.82 (1.06-3.13)1.82 (1.05-3.15)

*Adjusted for age, sex, heart disease, proteinuria, and eGFR at entry

Funding

  • NIDDK Support