Hypertension in developing countries

Summary

Data from different national and regional surveys show that hypertension is common in developing countries, particularly in urban areas, and that rates of awareness, treatment, and control are low. Several hypertension risk factors seem to be more common in developing countries than in developed regions. Findings from serial surveys show an increasing prevalence of hypertension in developing countries, possibly caused by urbanisation, ageing of population, changes to dietary habits, and social stress. High illiteracy rates, poor access to health facilities, bad dietary habits, poverty, and high costs of drugs contribute to poor blood pressure control. The health system in many developing countries is inadequate because of low funds, poor infrastructure, and inexperience. Priority is given to acute disorders, child and maternal health care, and control of communicable diseases. Governments, together with medical societies and non-governmental organisations, should support and promote preventive programmes aiming to increase public awareness, educate physicians, and reduce salt intake. Regulations for the food industry and the production and availability of generic drugs should be reinforced.

Introduction

Almost three-quarters of people with hypertension (639 million people) live in developing countries with limited health resources and where people have a very low awareness of hypertension and poor blood pressure control.1, 2 The proportion of people with hypertension who have their hypertension under control (the control rate) in some countries such as rural Ecuador is as low as 0·3%.³ Furthermore, the prevalence of hypertension is increasing and is predicted to grow by more than 500 million by 2025.4, 5 In South Africa, the risk of death from high blood pressure has increased by 25% in less than a decade.⁶ In India, prevalence of hypertension has increased by 30 times in urban populations over 25 years, and by 10 times in rural populations over 36 years.⁷ Serial surveys done in Tanzania with the same methods in 1987 and 1998 showed an increase in prevalence of hypertension from 25·4% to 41·1% in males and from 27·2% to 38·7% in females for rural and urban populations.⁸ This high prevalence of hypertension and poor hypertension control are important factors in the rising epidemic of cardiovascular disease in developing countries. Deaths from stroke in the Middle East and north Africa will nearly double by 2030.⁹ Between 1990 and 2020 mortality from ischaemic heart disease in developing countries is expected to increase by 120% for women and 137% for men.¹⁰ Two-thirds of all strokes and half of all coronary disease can be attributed to non-optimum blood pressure.¹¹

Reasons for the increasing prevalence and poor hypertension control need to be defined, and approaches to prevent and improve control should be identified. Explanation for regional and substantial rural–urban differences in prevalence might provide clues to the drivers of increasing hypertension prevalence.

We briefly summarise the magnitude of the hypertension problem in developing countries by providing data about hypertension prevalence, awareness, and treatment and control rates from population and regional surveys. We examine some of the known hypertension risk factors contributing to the rising epidemic of hypertension in many developing countries, particularly demographic, dietary, lifestyle, and genetic factors. We outline difficulties in hypertension control and suggest ways to achieve better control rates with cost-effective and affordable approaches, and we identify areas for future activities and clinical research.