Hypertension is the most common chronic condition in the United States and the number one reason for an office visit to a health care provider. The condition accounts for most medication prescriptions and is a major risk factor for heart disease and stroke. It is also a major risk factor for heart failure and chronic kidney disease. Throughout the world, hypertension is the number one attributable risk factor for death.1
Hypertension is both preventable and treatable in most patients; yet only approximately one-third of hypertensive patients in the United States have their BP controlled to levels that are proven to reduce the incidence of adverse cardiovascular events. Furthermore, less than 25% of patients with diabetes, which poses increased cardiovascular risks by itself, have their BP adequately controlled.1
CLASSIFICATIONS AND STAGES
Both diagnosis and clinical management are aided by classifying hypertension. The optimal method combines severity (the height of the BP), underlying cause (primary or essential versus secondary), and patient age (pathophysiology is different in younger persons compared with older persons). The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure defines hypertension in adults (18 years and older) as a systolic BP (SBP) higher than 140 mm Hg and a diastolic BP (DBP) higher than 90 mm Hg.
Hypertension is determined by the average of two or more seated BP measurements taken at each of two or more patient visits. An elevated BP is then determined to indicate stage 1 (SBP 140-159 mm Hg, DBP 90-99 mm Hg) or stage 2 (SBP 160 mm Hg or higher, DBP 100 mm Hg or higher) hypertension. The intervening levels (SBP, 120-139 mm Hg; DBP, 80-89 mm Hg) are described as prehypertension. Persons with prehypertension have an intermediate level of risk and may progress to definite hypertension.1
A single or reversible cause cannot be detected in more than 95% of hypertension cases, and these cases are defined as essential or primary hypertension. A definable cause for the hypertension is found in approximately 5% of cases.1 Hypertension that has a definable cause is referred to as secondary hypertension.
PREVALENCE AND AWARENESS
The latest published analysis by the CDC is based on data obtained from 1999 to 2002. It reported an increase in the prevalence of hypertension of 3.6% and that 28.6% of studied participants had hypertension.2 Extrapolated to the US population, this translates to 58.4 million Americans or approximately 1 in 4 persons. Another 25% of US adults are considered to be prehypertensive. The prevalence of hypertension increases with advancing age, and more than 50% of all Americans aged 60 years or older have hypertension.2
The proportion of hypertensive persons who are aware of their disease has not shown any significant change in the past 10 years. During the year 1999 to 2000, only 68.9% of patients were aware of their hypertensive condition.3
TARGET LEVELS
Hypertension manifests differently in younger patients compared with older patients;1 therefore, treatment thresholds are different. Initiating medication therapy in younger patients (younger than 60 years) with hypertension is clearly established. The benefits of drug treatment for older patients (older than 60 years) with an SBP lower than 160 mm Hg remain unproven. However, some evidence shows that mortality may be higher in patients aged 85 years and older with the lowest BP and that lowering DBP with medications may actually increase mortality.4
Controlled BP is defined as an SBP lower than 140 mm Hg and a DBP lower than 90 mm Hg. Target BP for patients with diabetes or chronic kidney disease is 130/80 mm Hg.1
The patient with uncomplicated hypertension is defined as a person without a compelling indication for a specific class of antihypertensive medication. The overriding goal of treating the patient with uncomplicated hypertension is to lower BP consistently to defined controlled levels. Achieving goal BP requires lifestyle modification and drug therapy. Most patients will need multiple drugs to achieve the recommended BP goals.1 JAAPA
Mary Hewett is an assistant professor in the PA program, Medical University of South Carolina, Charleston, and the department editor for When the Patient Asks. She has indicated no relationships to disclose relating to the content of this article.
REFERENCES
1. Chobanian A, Bakris G, Black H, et al. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA. 2003;289(19):2560-2572.
2. Centers for Disease Control and Prevention (CDC). Racial/ethnic disparities in prevalence, treatment, and control of hypertension - United States, 1999-2002. MMWR Morb Mortal Wkly Rep. 2005;54:7-9.
3. Hajjar I, Kotchen T. Trends in prevalence, awareness, treatment, and control of hypertension in the United States, 1988-2000. JAMA. 2003;290(2):199-206.
4. Mattila K, Haavisto M, Rajala S, Heikinheimo R. Blood pressure and five year survival in the very old. BMJ. 1988;296(6626): 887-889.
Click NEXT for Patient Information.