High blood pressure has the greatest impact on global attributable mortality of any other risk factor and accounts for the third leading cause of global burden of disease—64 million disability adjusted life years lost. The age-associated increase in blood pressure combined with the worldwide demographic increase in the aging population translates to an enormous emerging public health problem. In addition to the well-ascribed hypertension risk factors of cardiovascular disease and stroke, it is also a significant risk for chronic kidney disease, atrial fibrillation, congestive heart failure (CHF, including diastolic dysfunction), and cognitive impairment—each with a relative risk between 2.0 and 4.0. Lowering blood pressure by 10 mm Hg systolic and 5 mm Hg diastolic at age 65 years is associated with a reduction of up to 25% in myocardial infarction, 40% in stroke, 50% in CHF, and 10% to 20% overall decrease in mortality. Despite this knowledge, current rates of hypertension control are extremely low, especially among older women. In addition to illustrating the clinical importance of hypertension, these data are compelling in a call to improve both our knowledge concerning the mechanisms that underlie the age-associated increase in blood pressure to aid in its prevention as well as to make changes in the systems of care necessary to improve blood pressure control among those with hypertension.
Although high blood pressure should not be construed to be a normal aspect of aging, there is clearly an age-associated increase in blood pressure and in the prevalence of hypertension. The National Health and Nutrition epidemiological surveys have documented that hypertension is a very prevalent condition among older Americans. Based on this study's definition of hypertension—the average of three readings ≥140 mm Hg systolic and/or ≥90 mm Hg diastolic or those receiving an antihypertensive medication—the overall prevalence for hypertension among those aged 65 years or older ranges between 50% and 75%. For women aged 75 years and older, the prevalence exceeds 75%. Of note, there is an age–gender interaction in hypertension prevalence across age. At younger ages, prevalence rates are higher among men while above the age of menopause, there is a crossover when the prevalence in women surpasses that of men.
Another viewpoint on epidemiology is to examine the lifetime risk of developing hypertension as has been done in participants in the Framingham Heart Study. This study identified that among men and women participants who had normal blood pressure readings at age 55 years, nearly 85% developed Stage 1 or higher hypertension over 20 to 25 years of follow-up, their residual lifetime risk.
The current scheme to classify various levels of hypertension published by the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure, JNC 7 makes no adjustment for age. This classification scheme incorporates recent evidence that the cardiovascular risks associated with high blood pressure are continuous beginning at a level of 115/75 mm Hg and includes a prehypertension category (systolic from 120 to 139 mm Hg or diastolic 80–89 mm Hg). ...