Hypertension: treatments, diabetes, and developing regions.

Despite major progress in prevention and treatment, hypertension is the leading risk factor for cardiovascular disease and mortality. Worldwide, more than 7 million deaths can be attributed directly or indirectly to the eff ects of hypertension. This major cause of morbidity and mortality aff ects between 20% and 50% of adults, depending on nationality and age. At age 65 years, individuals have a 90% chance of developing hypertension by the time they reach 80 years of age. In the USA, the annual cost of care for hypertension is estimated to be about US$90 billion. More importantly, complications of hypertension have a substantial eff ect on quality of life because they aff ect the heart, brain, kidneys, and eyes. Hypertension aff ects not only adults but children as well, and although fewer children have hypertension than do adults, treatment costs are high and hospital stays are almost double the length, particularly if the child also has chronic kidney disease. To diagnose hypertension, treat, and follow-up patients, or investigate the mechanisms of hyper tension and action of antihypertensive agents, blood pressure has to be reliably measured. Moreover, reliable measurement of blood pressure is indispensable to study of the prevalence and control of hyper tension in populations, and to the assessment of health programmes and effi cacy of health policies. More than 100 years after the invention of the sphygmomanometer, measurements of blood pressure are still variable and unreliable, largely because strict guidelines for blood pressure measurement are seldom followed adequately in the hurried assessment of patients in busy offi ces and hospitals. The variability with which the technique of measurement of blood pressure is undertaken might explain why prevalence and control of hypertension are reported to vary so substantially between countries, even those with similar cultures and lifestyles. The Lancet’s Series on hypertension examines important aspects related to high blood pressure that are a cause for concern. Despite progress in the development of powerful antihypertensive agents and expansion of our mechanistic understanding of the disease, at best 50% of patients in developed countries have their blood pressure controlled to goal. Accordingly, Stéphane Laurent and colleagues examined new treatments for high blood pressure. Innovations in hypertension therapeutics have become more rare over the past 5 years than during the previous two decades, which saw the development and initial clinical use of angiotensin-converting-enzyme inhibitors, angiotensin-receptor blockers, a renin inhibitor, calcium-channel blockers, and new β blockers, and large multicentre randomised controlled trials to assess these drugs’ eff ects on hard endpoints. Diffi cult to treat, resistant hypertension in patients—who often also have diabetes, chronic kidney disease, sleep-disordered breathing, or other disorders—has become easier to control because mineralocorticoid receptor blockers are now used. Although these drugs are relatively weak antihypertensive agents on their own, they are much more potent when added to triple therapy consisting of a renin-angiotensin blocker, a calcium-channel blocker, and a thiazide-like diuretic. This increased effi cacy adds to the risk of hyperkalaemia, which needs particular surveillance in people with diabetes who might also have hyporeninaemic hypoaldosteronism or chronic kidney disease (or both). More frequent use of the thiazidelike diuretic chlorthalidone—that was, until recently, almost abandoned—has also helped to control the blood pressure of patients with resistant hypertension and is specifi cally recommended by the UK’s National Institute for Health and Clinical Excellence guidelines. However, patients with refractory hyper tension can still be unresponsive to four or more drugs. For these patients, a new treatment—catheter-based radiofrequency ablation of renal sympathetic nerves—is available. Although data See Perspectives page 555