Response to Prognostic Value of the Home Blood Pressure Variability: Which Is Best?
We appreciate the comments of Matsui and Kario.1 In our article, the main emphasis was to study the prognostic significance of the variability variables in home-measured blood pressure (BP) and home heart rate, by using SD, coefficient of variation, and average real variability.2
Referring to the first comment, we agree with Matsui and Kario1 that it would be of great interest to examine whether the maximum home systolic BP is associated with cardiovascular events and also with the variability variables of home BP. Maximum value of home BP and the difference between maximum value and mean home BP are, however, not real indices of BP variability, and, therefore, they were not examined in our article. This issue remains to be examined in the future studies. In our current article we did not examine the prognostic value of morning-evening difference. We acknowledge that morning-evening difference has been found to be an independent determinant of cardiac damage in untreated hypertensive patients. However, it is not known whether a greater morning-evening difference is a predictor of cardiovascular events in the general population. This issue has to be clarified in the future studies.
Subjects with ≥14 measurements of home BP and home heart rate were included in our study. However, the minimum number of home measurements needed for the assessment of prognostic significance in home-measured BP variability remains to be determined in the future studies.
Diastolic home BP variability variables were slightly stronger predictors of cardiovascular events than systolic ones. However, the differences were nonsignificant, because the CIs were overlapping. Therefore, any profound conclusions cannot be derived regarding whether diastolic BP variability is a better predictor of cardiovascular events than systolic variability.
In our recent article there was no difference in the variability of home BP between subjects with and without sleep apnea symptoms.3 However, self-reported insomnia symptoms and both short (≤6 hours) and long (≥9 hours) self-reported sleep duration were associated with higher home BP variability. At this moment it is not known whether sleep disorders and greater variability of home BP are causally related predictors of cardiovascular risk.
Jouni K. Johansson
Teemu J. Niiranen
Pauli J. Puukka
Antti M. Jula
Population Studies Unit
Department of Chronic Disease Prevention
National Institute for Health and Welfare
Sources of Funding
The project organization created for the study involved the National Institute for Health and Welfare, the Finnish Centre for Pensions, the Social Insurance Institution of Finland, the Local Government Pensions Institution, Statistics Finland, the Finnish Work Environment Fund, and the Finnish Institute for Occupational Health.
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- © 2012 American Heart Association, Inc.
- Matsui Y,
- Kario K
- Johansson JK,
- Niiranen TJ,
- Puukka PJ,
- Jula AM