Hypertension in ethnic groups: epidemiological and clinical perspectives.

In the UK and other developed nations, hypertension and its vascular complications are more common in ethnically African and South-Asian communities compared with Europeans. While these conditions are less common in rural India and Africa, they present a rising problem in expanding cities in all developing countries. Hypertension is, therefore, mainly related to environmental and lifestyle factors rather than genetically determined racial differences. Studies in the USA and elsewhere show that the striking differences in the prevalence of hypertension between people of African and European origin are greatly reduced after adjustment for socio-economic status. One important and probably genuine racial difference between ethnic groups is the significantly suppressed activity of the renin-angiotensin-aldosterone system in African-origin hypertensive patients. As a consequence of this, they are rather more sensitive to a low-salt diet but significantly less sensitive to drugs that block the renin-angiotensin-aldosterone system (angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers) and beta-blockers. There is also evidence that renin suppression is common in Japanese and Chinese hypertensive patients as well, although no direct comparisons between these two groups with European-origin patients have been carried out. The management and control of hypertension is unsatisfactory in all ethnic groups and all nations. No one group needs particular targeting; all need better quality systematic care.