BO

OK

RE

VIE

W

Book Review

Essential Hypertension and its Causes: Neural and Non-neural Mechanisms, P. Korner. Oxford University Press(2007)

This is a rare treat. After a lifetime of research andscholarship, still at the top of his game one of our

best scientists plants a stake in the ground and states thathe understands the causes of essential hypertension. Heeschews the usual dismissal line of “the causes of essentialhypertension are not known. . .” and gets into a serious anderudite analysis of the world’s greatest preventable healthproblem. This is a polygenic condition under strong envi-ronmental influences. A haemodynamic problem arisingfrom arteries, it involves every organ in the body partic-ularly the brain, heart and kidneys and their numerouscontrol mechanisms. He rightly points out that this canonly be addressed using a systems analysis approach.

For over a decade, Paul Korner compiled ideas andexperimental results, assimilated new knowledge and

tiation. In particular he describes the amplifier roles of thevascular changes that ensue, cardiac hypertrophy, the shiftin baroreceptor function to control blood pressure aroundits new set point and the participation of the kidney. Thebook is densely filled with descriptions of pertinent experi-ments and figures showing the original data. No statementgoes unsupported and while not everyone will agree withevery conclusion, the rigour is indisputable. The reader israpidly transported back and forth between rats, mice andother models of hypertension to human genetics and dailylife experiences, all described in the context of complexnon-linear systems. Four daily life pressure stimuli areanalysed in detail: these are psycho-social stress; exces-sive dietary salt intake; obesity; obstructive sleep apnoea.All are common in our contemporary experience and theauthor shows a refreshing ability to see ways in whichobservations in the cold, rational world of the experimen-tal laboratory can be extrapolated to the rough and tumbleof the human condition.

even new disciplines such as genomics, and systematicallydeveloped a theory and a vast amount of experimentalsupport.

A key starting point is that the control systems involved,particularly those in the brain that turn acute short-termresponses into long term maladaptive ones, are both non-

He concludes that there are two common forms of essen-tial hypertension. One is stress and salt related the other,obesity hypertension. These exist against a polyglot ofgenetic susceptibility, lifestyle choices and environmentalimpositions.

Monographs of this kind are unfortunately rare.

linear and adaptive. He borrows from Kandel’s work onmolluscs which demonstrated a strengthening of synaptic

Inevitably they are very personal and reflect the knowl-edge and skills and experiences of the author. In this

onsl righ

transmission in response to repeated aversive stimuli andsuggests that in susceptible individuals repeated acuteexposure to stress of one form or another creates a longterm pattern which is both haemodynamically and neuro-physiologically reminiscent of the hypothalamic defencereaction. Like most good ideas this seems obvious andwould be of no surprise to the lay population who havealways considered hypertension and stress as close syn-onyms. However to those active in hypertension researchthis is a critical breakthrough in thinking as we have alwaysstruggled with the question of how acute short-termchanges in blood pressure in response to aversive stimuli,exercise and other environmental influences could turninto long term changes in the set point about which bloodpressure fluctuates during our day to day activities. Kornerdoes not, however, fall into the usual trap in describingthe physiological mechanisms involved in hypertension,of leaving things stand with a single mechanism involv-ing just one control system or organ. In fact, he arguesstrongly against the notion that has had wide currencypopularised by Guyton, but developed further by manyothers, that hypertension starts and ends in the kidney.Korner supports the view that non-neural mechanismseventually dominate the picture and eventually obscurethe role that he proposes neural mechanisms play in its ini-

© 2009 Australasian Society of Cardiac and Thoracic SurgeAustralia and New Zealand. Published by Elsevier Inc. Al

case a good dose of intellect has been added to a wealthof experience and knowledge and while this still leavesplenty of questions for hypertension research to answer itestablishes a very good working hypothesis with plenty ofnovel and testable hypothesis. This book patently revealsa thirst for the truth in its author who, I am sure, will bejust as happy if his hypothesis stand or falls in the lightof future investigation. He wants to find an answer. Onreflection this is a very worthwhile aim. As he points out,hypertension is common, under recognised, and treatedin a non-specific, one size fits all manner with drugsand increasingly drug combinations that never targetthat elusive cause. He presents a cogent argument thatthey key to prevention lies in things we know aboutsuch as regular physical activity, and avoiding excessivesalt intake. If only we could control the stress in ourlives.

The book is a marked contrast with the familiarmulti-authored compendiums in which authors addressdifferent aspects of the manifestations of hypertension.As chapter authors we sometimes contradict each other inthe same book and Essential Hypertension and its Causesoffers a synthesis, which can never be gained from a stan-dard text book. It will appeal to all those with a seriousinterest in hypertension.

and the Cardiac Society ofts reserved.

1443-9506/04/$36.00doi:10.1016/j.hlc.2009.02.004

BO

OK

RE

VIE

W

Heart, Lung and Circulation Jennings 2372009;18:236–237

Garry Jennings ∗Baker IDI Heart and Diabetes Research Institute,

75 Commercial Road, 3004, Australia∗ Tel.: +61 3 8532 1111; fax: +61 3 8532 1100.

E-mail address: garry.jennings@baker.edu.au

23 December 200817 February 2009