With this issue, Volume 3 of JASH comes to a close. As indicated elsewhere in this issue, our success would not have been possible with the dedication and expertise of our reviewers who are listed and to whom thanks and gratitude is expressed for their efforts and commitment.
The first article in this issue is a critical review of the evidence supporting a causal link between sympathetic nervous system activity, obesity and blood pressure by Drs. Feldstein and Julius. The latter has devoted a productive career to elucidating many links in this now-established chain of events which is being recognized with increasing frequency among most populations. The review focuses not only on the epidemiological and physiological evidence but also on the down-regulation of beta adrenergic receptor activity. It will be interesting to see if future efforts can utilize this information in the prevention of these scourges predisposing to cardiovascular morbidity and mortality.
Dr. Smith and colleagues conducted a timely and thorough review of the literature reporting the relationships between exercise-induced changes in systolic blood pressure and the subsequent development of hypertension and cardiovascular morbidity and mortality. While it has long been recognized that an excessive rise in blood pressure during standardized exercise tests can herald the subsequent development of fixed hypertension, the information regarding exercise-related blood pressure change as a predictor of events has been uncertain. Among hypertensives not known to have heart disease, such a rise is associated with subsequent cardiovascular events. The authors cite studies indicating that a brisk rise in blood pressure with exercise in subjects with known or suspected heart disease may not be strongly predictive of future events, but that the failure of blood pressure to rise with exercise in such individuals was a dire predictor of adverse cardiovascular outcomes. Obviously, since these studies were conducted over a long period of time, when the criteria for “normal” blood pressure was changing, inconsistency might be anticipated. Moreover, the review is limited by the precision with which patients were categorized as having heart disease or not. Nonetheless, in view of our aging population and the increasing utilization of stress testing for cardiac evaluation, the patterns of blood pressure response assume greater clinical significance. We look for further information on this important topic.
Lima et al provide new information concerning the regulation of vascular contractile and relaxation responses. The O-linked attachment of β-N-acetyl-glucosamine can influence a variety of proteins involved in vascular function. The authors studied several probes to further investigate the role of this process on vascular biology. Many productive findings in this area are anticipated in the future.
It is well known that carotid intimal-medial thickness (IMT) is often correlated with coronary artery disease (CAD) in humans. Simova and colleagues evaluated flow-mediated vasodilation as well as carotid IMT in relationship to significant coronary artery disease in 492 patients suspected of coronary artery lesions undergoing coronary angiography. They observed that the vascular response, flow-mediated vasodilation, was more closely correlated with the presence of significant coronary disease than IMT and that neither measure replaced the accuracy of the stress electrocardiogram for the primary assessment of CAD.
Giles and colleagues report the results of a comparison of three different angiotensin receptor blockers (ARBs) as monotherapy in black and white hypertensives. While they did not observe significant differences in the blood pressure responses on an ethnic basis, they did note that the effect of the ARBs on systolic pressure in black subjects was significant while that in diastolic pressure was not in this subgroup, but that both groups had significant reductions in systolic pressure with the ARBs. Olmesartan appeared to have greater and quicker efficacy than the other two ARBs studied, losartan and valsartan. Whether these differences were related to doses employed or frequency of administration of the agents studied is not clear.
Duh and colleagues reviewed outcomes in 1.6 million hypertensives for which information could be obtained in a managed care database. Over a three-year period 510,000 (31.9% of the population) sustained a cardiovascular event and 39% of these individuals had more than a single event. This is an astounding observation in view of a commonly held belief that only a small number of hypertensive individuals are at risk for events. It would certainly be of interest to know if there were any other distinguishing characteristics that could be clinically useful in identifying the high-risk individuals better. Furthermore, these findings appear to clearly establish the benefit of early and effective antihypertensive therapy in preventing such events and that such aggressive treatment does indeed diminish health care costs. At a time when this country is debating the extension of health care to more of our citizens and how to fund this coverage, this information is particularly useful.
The significance of “White Coat Hypertension” (WCH) in general, its presence in children and its relationship to target organ damage has been controversial. Litwin and colleagues present their observations in 183, 5-19 year-old children referred for evaluation of hypertension. They identified WCH in 30% of these young people. Importantly, they found no differences in the prevalence of target organ disease between those with WCH and those with sustained hypertension. This observation provides important new information concerning WCH in childhood and its relationship to target organ damage.
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