Hypertension in elderly--an overview.

ABSTRACT

Hypertension (HT) is a common disease in elderly. It has different pathophysiologic, clinical and therapeutic implications in this age group. Due to loss of arterial wall elasticity with age, major vessels including aorta become stiff and less distensible. As age advances, these stiff vessels also lose beta adrenergic responsiveness with unchanged alpha adrenergic responsiveness. These together raise peripheral vascular resistance and aortic impedance which needs a powerful systolic ejection of left ventricle to maintain cardiac output. Result is rise in systolic blood pressure (SBP) and increase in left ventricular (LV) mass with compromised cardiac output and renal blood flow. Participation of renin-angiotensin system and kidney in HT pathogenesis in elderly are minimum. Diagnosis of HT in elderly is made if SBP > 140 mm Hg and/or diastolic blood pressure (DBP) > 90 mm Hg or is taking antihypertensive medications. Isolated systolic hypertension (ISH) means SBP > 140 mm Hg with DBP < 90 mm Hg. Measurement of blood pressure (BP) is problematic, mainly due to pseudo HT, postural hypotension and white-coat HT. HT in absence of end organ changes suggest pseudo HT. Postural hypotension must be detected and treated. Systolodiastolic HT, carried over from middle age is the commonest type of HT in elderly. ISH is also common (10%). Atherosclerotic renovascular disease can cause secondary HT. Therapy is always needed in HT in elderly. Chance of coronary artery disease (CAD) and cerebrovascular accident (CVA) are quite high amongst elderly hypertensives. SBP is more dangerous than DBP. Benefits of therapy are more when compared to young. HT should be treated if SBP > 160 mm Hg and/or DBP > 90 mm Hg. ISH needs therapy if SBP > 160 mm Hg. The benefits of therapy becomes less after 80 years. Treatment goal should be to keep BP below 140/90 mm Hg. Therapy should be gradual and stepwise. Na-restriction should be modest. Diuretics (e.g., thiazide 25 mg/day) are the drug of choice unless contra-indicated. Beta blockers are inferior agents compared to diuretics unless angina or acute myocardial infarction (AMI) is present. Angiotensin converting enzyme (ACE) inhibitors are drug of choice only if congestive cardiac failure (CCF) and/or diabetes is present or other drugs are contra-indicated. Calcium entry blockers (CEB) are new but very good alternative to diuretics in elderly. Due to abnormal physiology, pharmacokinetics and drug interactions, side-effects are very common in elderly. They should be detected early and treated.