102THE INFLUENCE OF AGE AND SYSTOLIC BLOOD PRESSURE ON BLOOD PRESSURE VARIABILITY AMONG HEALTHY OLDER INDIVIDUALS

Abstract

Introduction: Blood pressure variability (BPV) has drawn increasing interest among the scientific community with an increasing body of evidence linking increased BPV with cardiovascular outcomes and mortality [1, 2]. Blood pressure variability is the fluctuation of blood pressure within a period of time, which can be over a very short-term (beat-tobeat - HRV) to long-term (visit-to-visit). Mean arterial blood pressure is directly correlated with 24-hour BPV and age and is associated with hypertension. However, the association between age and BPV has yet to be explored. Thus, this study is intended to evaluate the relationship between age and systolic blood pressure with BPV among healthy older individuals. Method: One hundred and twenty-two healthy subjects, free from any cardiovascular disease, cerebrovascular disease, neurological disease, diabetes mellitus or cancer participated in this study and divided into three age groups (I: 55-64 ys, II: 64-74 ys and III: 75 ys and above). Participants were recruited through electoral roll for the parliamentary constituencies of Petaling Jaya, Selangor, Malaysia and Kuala Lumpur, Malaysia. Continuous beat-to-beat blood pressure signals were recorded during supine rest over ten minutes. Blood pressure variability was determined with standard deviation of real variability (SDRV). (1) Results: There is no significant difference in height, weight and systolic BP between age groups. Supine systolic BP was moderately positively correlated with logarithm transformed BPV (r = 0.281, p = 0.002), but there was no significant association between age and BPV (r = 0.107 and p = 0.238). Older individuals with higher supine systolic BP ( > = 116 mmHg) are found to have significantly higher HRV (p = 0.007) compared to those with BP<116 mm Hg. Systolic BP remained an independent predictor of higher BPV following adjustment for age using linear regression methods (p = 0.008). Conclusion: This study has demonstrated that resting BPV using SDRV increases with increasing supine BP. Increasing age was not associated with higher systolic BP or increased BPV among healthy older individuals in our setting.