THE IMPORTANCE OF SYSTOLIC BLOOD PRESSURE
Recent evidence from the National Health and Nutrition Examination Surveys (NHANES), as well as from the Framingham Heart Studies, indicates that systolic blood pressure is a better determinant of cardiovascular risk than diastolic blood pressure.
In this issue of the JCH, Whyte and colleagues reach several conclusions based on a reanalysis of the NHANES data. Not only is systolic blood pressure more important than diastolic in determining risk; they note that classification of various stages of blood pressure on the basis of systolic blood pressure alone would be more accurate than if diastolic pressure were used. This review also issues a challenge. In most clinical trials, as well as in surveys of blood pressure control in the United States, diastolic blood pressure is controlled in a high percentage of patients—more than 75%–80% in most cases. In contrast, systolic blood pressure control at the goal level of <140 mm Hg is achieved in fewer than 60%, even in carefully controlled studies. The authors make a strong case for paying more attention to systolic blood pressure elevation.
ALPHA BLOCKERS AND PROSTATE DISEASE
In another paper on drug therapy of hypertensive patients, Martell and colleagues describe the results of treatment in a group of hypertensive individuals with benign prostatic hypertrophy. Patients who were on one antihypertensive drug and whose blood pressures remained elevated were given the α blocker doxazosin in increasing dosages. Various parameters were employed to analyze the effects of this agent on prostatic symptoms as well as prostate function. The authors concluded that the α blocker, when added to other drug therapy, not only improved symptoms of prostatism but also lowered blood pressure still further.
Recent data, however, indicate that α‐blocker therapy probably is not preferred in the initial management of hypertension. Reductions in morbidity and mortality are greater when a diuretic is used. The Sixth Joint National Committee (JNC) did not recommend α blockers as initial treatment, and this has been reaffirmed by the results of newer trials; these agents are not suggested as first‐line therapy. However, in patients with prostate disease who are already receiving antihypertensive drugs, the addition of an α blocker may lower blood pressure still further and improve symptoms of prostate disease.
BETA BLOCKERS—STILL INDICATED IN HYPERTENSION TREATMENT?
Dr. Hanes and her group discuss the benefits and possible problems with the use of β blockers in the management of hypertension and other cardiovascular conditions. Although recent papers have stressed potential problems with the use of these agents and the fact that, in the elderly, diuretics may be more effective in reducing coronary artery disease events, the authors correctly conclude that there is a place for β blockers in the management of hypertension.
In both the young and the elderly, β blockers reduce the occurrence of strokes and congestive heart failure. The data on elderly patients suggest that they are less effective in coronary heart disease. However, as noted by Hanes, these conclusions are based on trials with a high dropout rate and large numbers of crossovers to other medications. There is some concern about the increase in triglyceride levels and lowering of HDL levels in patients who are treated with β blockers. These effects and effects on insulin resistance may not, however, be of clinical importance, based on the results of newer trials in which a β blocker‐based regimen has been compared to other antihypertensive therapy in diabetics and other patients. A significant reduction in all cardiovascular events was noted in the β blocker‐based treatment groups. Hanes and her colleagues highlight the fact that in addition to their potential benefits in the treatment of hypertension, β blockers have been found to be beneficial in the management of congestive heart failure, the post‐myocardial infarction patient, and various arrhythmias. They concur with the recommendation of the JNC that β blockers alone, or in combination with a diuretic, are among the preferred choices for the management of hypertension.
OBESITY
Dr. Pickering, in an interesting column, focuses on the growing evidence of obesity in this country and explores some reasons why adolescents and younger people are becoming more obese. He cites eating habits and less exercise as the probable major causes and offers suggestions for physicians to become more active in obesity control.
DIABETES, RENAL DISEASE, AND HYPERTENSION
Finally, Drs. Weber and Weir discuss an important disease entity. Diabetes is increasing rapidly, both in the U.S. and worldwide. It is clearly related to the occurrence of obesity and the metabolic syndrome, which includes abdominal obesity, hypertriglyceridemia, low HDL levels, and hypertension.
Whereas diabetologists have, for many years, focused on the management of glycemia with nutritional intervention and careful glucose monitoring, it has been shown in recent clinical trials that more effort must be invested in correcting other abnormalities—specifically, hypertension and hyperlipidemia—in the diabetic population. Results indicate that cardiovascular morbidity and mortality, both related to diabetes, might be more dramatically affected by lowering blood pressure, for example, than by achieving glycemic control.
Drs. Weber and Weir review results of treatment of high‐risk diabetic hypertensives from three new trials. Results demonstrate that progression from less severe to more severe renal disease, as well as progression from established to end‐stage renal disease, transplantation, or death, can be retarded with a treatment regimen that includes an angiotensin II receptor blocker (ARB), relative to a treatment program that does not include an ARB, an ACE inhibitor, or a calcium channel blocker.
These trials build on previous evidence that agents that block the renin‐angiotensin system (usually in combination with a diuretic) are helpful, in diabetics both with and without proteinuria, in preventing or slowing the progression of renal disease.
These observations, plus recent data from other clinical trials, should lead to a change in recommendations for initial therapy. It is reasonable to assume that ACE inhibitors, usually combined with a diuretic, should now be included as initial therapy in hypertension management and that ARBs (again, usually with a diuretic) should now be recommended as one of the preferred therapies in the management of patients with diabetes, with or without proteinuria.
It is obvious that more attention must be paid to treating hypertension, the metabolic syndrome, diabetes and obesity.