Abstract
The prevalence of hypertension increases with age making it a significant health concern for older persons. Aging involves a range of physiological changes such as increases in arterial stiffness, widening pulse pressure, changes in renin and aldosterone levels, decreases in renal salt excretion, declining in renal function, changes in the autonomic nervous system sensitivity and function and changes to endothelial function all of which may not only affect blood pressure but may also affect individual response to pharmacotherapy used to manage hypertension and prevent end organ damage and other complications associated with poor blood pressure control.
Unlike many chronic conditions where there is limited evidence for management in older populations, there is good evidence regarding the management of hypertension in the elderly. The findings from multiple large, robust trials have provided a solid evidence-base regarding the management of hypertension in older adults, showing that reduction of blood pressure in older hypertensive populations is associated with reduced mortality and morbidity. Diuretics, agents action on the renin angiotensin system, beta blockers and calcium channel blockers have all been well studied in older populations both in view of the benefits associated with blood pressure lowering and the risks associated with associated adverse events. While all antihypertensive agents will lower blood pressure, when managing hypertension in older persons the choice of agent is dependent not only on the ability to lower blood pressure but also on the potential for harm with older persons. Understanding such potential harms in older populations is essential with older persons experiencing increased sensitivity to many of the adverse effects such as dizziness associated with the use of antihypertensive agents.
Despite the wealth of evidence regarding the benefits of managing hypertension in the old and very old, a significant proportion of older individuals with hypertension have suboptimal BP control. While there is good evidence supporting blood pressure lowering in older antihypertensive agents, these have not yet been optimally translated fully into clinical guidelines and clinical practice. There appear to be considerable differences between guidelines in terms of the guidance given to clinicians. Differences in interpretation of the evidence, as well as differences in study design and populations all contribute to differences in the guideline recommendations with respect to older populations, despite the strength of the underlying scientific evidence. Differences around who is considered "old" and what BP targets and management are considered appropriate may lead to confusion among clinicians and further contribute to the evidence-practice lag.