John Laragh, MD, and his colleague, Jean Sealey-Laragh, DSc, have advanced the understanding of the determinants of high blood pressure by clarifying the role of an enzyme called renin in hypertension. They defined the modern theory of blood pressure as being strongly involved with the kidneys, hormones, and salt. They developed the Laragh Method, which analyzes the results of the plasma renin test to determine the optimal choice of anti-hypertensive drug(s) for patients with high blood pressure. The goal is to be able to provide a patient with effective treatment that uses as few drugs as possible (ideally just one or two), enhancing patient compliance while reducing the cost of care.
For more information, please contact Dr. Jean Sealey-Laragh:
Details of the Laragh Method
The Laragh Method states that there are only two final determinants of all long-term human blood pressure, whether normotension or hypertension: (1) the body salt content and (2) the plasma renin level. Laragh defines this interaction mathematically in the Blood Pressure Equation:
BP = (body salt – volume V content) x (plasma renin R level)
In this equation, dietary salt provides the primary volume support for normal blood pressure and flow, and plasma renin sustains normal blood pressure whenever enough salt-volume is not available. Thus, a rise in plasma renin after salt depletion maintains normal blood pressure levels — although at the cost of reducing flow to tissues.
Within this volume-vasoconstriction interactive equation, all human hypertension is sustained by abnormally high (sodium-volume V) X (plasma renin R) products, involving either a body salt excess relative to plasma renin levels, or excess plasma renin relative to body salt. Thus, hypertension is sustained by either excess salt, excess renin, or subtle excesses of both renin and salt.
Accordingly, by using an ambulatory renin test to solve for renin in the blood pressure equation, it is possible to readily identify and correctly treat each patient. Those with low plasma renin levels have too much salt and should be first treated with a natriuretic anti-V drug. Those whose plasma renin levels are not suppressed should first be treated with an anti-renin R drug. This approach seeks to correct most hypertension by giving only one correct V or R drug type daily for life for most patients, while also preventing or arresting fatal renin-mediated vasculotoxic sequelae in the R patients. Moreover, renin testing of unresponsive patients already receiving multiple V and/or R drugs readily identifies whether excess V or excess R was the cause of each treatment failure.
The Laragh Method's analytical strategy corrects most hypertension (65-90 percent) by using one — or at most two — drugs a day for life, instead of the two to six drugs given daily to 63 percent of patients to correct only 67 percent of them in the large NHLBI-sponsored ALLHAT Trial and endorsed by JNC7.
The Laragh Method enables correct and superior treatment of all hypertension, thereby extending the lives of millions of patients while using fewer drugs. Moreover, by eliminating the use of unneeded antihypertensive drugs in each hypertensive patient and by using generic drugs, lower costs — amounting to savings of many billions of dollars annually — are now a reality.