Diurnal variation of arterial stiffness in healthy individuals of different ages and patients with heart disease

Abstract

Background. Arterial stiffness can be measured using various non-invasive methods. It is not well established whether it is necessary to standardize the time of the day when performing these measurements. The aim of the present study is to examine the effect of daytime on arterial stiffness in individuals with and without heart disease. Methods. We investigated the diurnal variation of cardio-ankle vascular index (CAVI) and carotid femoral pulse wave velocity (cfPWV). CAVI and cfPWV were measured in 70 participants (23 healthy young individuals [HY], 22 healthy elderly individuals [HE], 25 patients with heart disease [HD]) at 09:00, 13:00 and 17:00 h. Results. There was a significant diurnal variation in CAVI with the highest values at 09:00 h in both univariate and multivariate analysis. After adjusting for age, sex and MAP (mean arterial pressure), CAVI maintained a significant highest values at 09:00 h, which was 4% higher than at 13:00 h (p = 0.022) and 5% higher than at 17:00 h (p = 0.002). However, a lack of diurnal variation was found in cfPWV in multivariate analysis in our study population. Conclusion. Our findings suggest that it does not appear mandatory to measure cfPWV at the same time of day. However, standardizing the time of day for CAVI is important in routine clinical practice and longitudinal studies.

Key Words::

• Vascular stiffness
• blood pressure
• circadian rhythm
• aging
• cardiovascular disease

Acknowledgements

This study was sponsored by an unrestricted grant of Fukuda Denshi (Tokyo, Japan). We would like to particularly thank the following people for their contributions to this manuscript: PD Dr Christian Schindler for his assistance in statistical analysis and result interpretation; Dr Andrea Hans Meyer for his extensive discussions on the statistical methods; and Dr Qing Wang for her statistical advice and reading of the manuscript. Last but not least, thanks to all the participants in the study.

Authors’ contributions

Initial study design was from the primary investigator AST; participant recruitment was done by MC and AST; measurements of CAVI and cfPWV were performed by YL and MC; labor data collection was done by MC, YL and HH; statistical analysis was done by YL and AST; data interpretation was done by YL, AST, MC, JRR, LGO and HH; the first and final draft of manuscript was edited by YL, JRR and LGO and AST. All authors read and approved the final manuscript.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.