Search

Since the publication of a paper by the American Society of Hypertension, Inc. Writing Group in 2003, some refinements have occurred in the definition of hypertension. Blood pressure is now recognized as a biomarker for hypertension, and a distinction is made between the various stages of hypertension and global cardiovascular risk. This paper discusses the logic underlying the refinements in the definition of hypertension., (2009 Wiley Periodical, Inc.)

A substantial body of evidence has implicated several aspects of diet in the pathogenesis of elevated blood pressure (BP). Well-established risk factors for elevated BP include excess salt intake, low potassium intake, excess weight, high alcohol consumption, and suboptimal dietary pattern. African Americans are especially sensitive to the BP-raising effects of excess salt intake, insufficient potassium intake, and suboptimal diet. In this setting, dietary changes have the potential to substantially reduce racial disparities in BP and its consequences. In view of the age-related rise in BP in both children and adults, the direct, progressive relationship of BP with cardiovascular-renal diseases throughout the usual range of BP, and the worldwide epidemic of BP-related disease, efforts to reduce BP in nonhypertensive as well as hypertensive individuals are warranted. In nonhypertensives, dietary changes can lower BP and delay, if not prevent, hypertension. In uncomplicated stage I hypertension, dietary changes serve as initial treatment before drug therapy. In hypertensive individuals already on drug therapy, lifestyle modifications can further lower BP. The current challenge is designing and implementing effective clinical and public health interventions that lead to sustained dietary changes among individuals and more broadly in the general population.

The prevalence of hypertension increases with advancing age, due primarily to increases in systolic blood pressure. Systolic hypertension is the most common form of hypertension in individuals over 50 years of age and reflects pathologic decreases in arterial compliance. Systolic blood pressure elevation is a more important risk factor for cardiovascular disease than is diastolic blood pressure elevation. Stage 2 hypertension, defined as blood pressure > or =160/100 mm Hg, is often found in older persons, who are at highest risk for cardiovascular events. In this clinical review, hypertension experts utilize a case study to provide a paradigm for treating older patients with stage 2 hypertension.

Dr. David Ayman (1901-1986) was an astute clinician and observer who challenged medical dogma by performing placebo-controlled studies and by meticulous measurement of blood pressure under standardized conditions. He demonstrated that almost all drugs reported to have an antihypertensive effect in the early 20th century had achieved nothing more than placebo response. He noted the marked variability of blood pressure and devised methods to reduce that variability. These observations led to his publications concerning what is now known as "white coat" or office hypertension. He determined blood pressure personally in 1524 members of 277 families over three generations and made observations on the hereditary nature of hypertension that countered the single-gene thinking of the day. His work is proof that clinical inquisitiveness, hard work, and the courage to challenge conventional wisdom can result in significant contributions to medicine and science.

Blood pressure increases with increasing body mass index (BMI) and BMI is linearly related to blood pressure in population studies. Obesity has been said to cause resistance to antihypertensive medications. We compared short-term and 1-year blood pressure response by BMI category and weight change with hydrochlorothiazide, atenolol, diltiazem-SR, captopril, clonidine, prazosin, or placebo in 1292 male veterans. Drug doses were titrated to achieve goal diastolic blood pressure <90 mm Hg over 4-8 weeks. Patients who achieved goal blood pressure were maintained for 1 year. BMI did not predict change in systolic, diastolic or pulse pressures during titration for any drug. At 1 year obese patients (BMI >30) were 2.5 times more likely to have diastolic blood pressure controlled by atenolol than normal weight (BMI <27) patients (p=0.01). Only prazosin patients gained weight: 1.7 lb (end-titration, p<0.0001; 1-year, p=0.02). Obesity does not appear to cause resistance to antihypertensive medications.