With these assumptions as my starting point - what is the problem?
The problem begins with the fact that a BP of 120/80, which is a national average in some studies, is neither healthy nor ideal. The authors are making a serious error or equating normality/average with health, a rather common error in medicine.
In fact 120 over 80, representing the systolic and diastolic blood pressures and which are the highest and lowest bp's achieved by the heart during each heart beat, are acknowledged by all major medical institutions, including the AHA, as less than ideal. The Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure the organization responsible for hypertension treatment guidelines stated that BP's of 120-129 systolic over 80-84 diastolic were "prehypertension". (JAMA 2003:289;2560-2571) Ideal or optimal BP is less than 120/80 and in fact the lower one's blood pressure the better (subject to the limitation that very low blood pressures do not cause symptoms).
What no one wants to say is that there is a linear positive relationship between blood pressure levels in a population and increasing risk of stroke and heart attack (the two main consequences of hypertension) and that this increasing risk is apparent even when comparing groups with average bp of 120/80 to those with 110/70 and they in turn are at higher risk than those with 100/60 mm hg. There is no specific # that discriminates the healthy from the unhealthy. Studies, including the Framingham Heart Study (the most famous American epidemiologic study of heart disease), find that as much of 40% of the risk of stroke and heart disease occurs among people with BP's less that 140/90. Also, as we age as a population the average BP increases yearly with increasing risk.
The problem, however, of what is a healthy blood pressure is complicated by a second even more serious problem in the measurement and diagnosis of blood pressure. All of these BP criteria are derived from studies of casual blood pressures, that is bp's taken of patients in a doctors office after several minutes of waiting and relaxing. It is believed these bp's represent accurately what a person's true average underlying bp is and that it is this bp that is the determiner of risk of heart disease.
Recently studies of individual's ambulatory blood pressure obtained using automated monitors that can measure blood pressure while individuals are at work, home, play, and sleep have demonstrated that it is one's average ambulatory bp, especially ones work time ambulatory bp, that is the best predictor of subsequent disease (and not one's casual office obtained bp). And, unfortunately, there is a big discrepancy between most peoples casual office obtained bp's and what their bp is at work. So much so that millions of American are being misdiagnosed as 1) either having hypertension when they do not; that is their bp is up in the doctors office but normal when they wear an ambulatory bp monitor at work (what is called White Coat Hypertension) or 2) there is a failure to diagnosis hypertension because many people have normal bp's in their doctor's office but when they wear an ambulatory bp monitor it is found that their bp is elevated at work and/or at home. Researchers call this problem "hidden hypertension".
Much of this problem of mis-diagnosis could be avoided if individuals routinely were provided with an opportunity to wear an ambulatory bp monitor but the health industry is reluctant to pay for this expense despite the fact that literally millions of people are being mis-diagnosed. Taken together these problems of equating normal/average with healthy and our inaccurate diagnostic methodology means millions of Americans are either being over treated for hypertension they do not have or not being treated for hypertension which is apparent at work but not in the doctors office. This is a major public health disaster.
In Part 2 of this blog we will address the issue of the role that work plays in the creation of the problem of hypertension and how knowing more