E p i d e m i o I o g y / H e a 11 h S e r v i c e s / P s y c h o s o c i a I Research N A L A R T I C L E Global Burden of Diabetes, 1995-2025 Prevalence, numerical estimates, and projections HILARY KING, MD, DSC RONALD E. AUBERT, PHD WILLIAM H. HERMAN, MD, MPH OBJECTIVE — To estimate the prevalence of diabetes and the number of people with dia- betes who are ^20 years of age in all countries of the world for three points in time, i.e., the years 1995, 2000, and 2025, and to calculate additional parameters, such as sex ratio, urban- rural ratio, and the age structure of the diabetic population. RESEARCH DESIGN AND METHODS — Age-specific diabetes prevalence estimates were applied to United Nations population estimates and projections for the number of adults aged 5:20 years in all countries of the world. For developing countries, urban and rural pop- ulations were considered separately. RESULTS — Prevalence of diabetes in adults worldwide was estimated to be 4.0% in 1995 and to rise to 5.4% by the year 2025. It is higher in developed than in developing countries. The number of adults with diabetes in the world will rise from 135 million in 1995 to 300 mil- lion in the year 2025. The major part of this numerical increase will occur in developing coun- tries. There will be a 42% increase, from 51 to 72 million, in the developed countries and a 170% increase, from 84 to 228 million, in the developing countries. Thus, by the year 2025, >75% of people with diabetes will reside in developing countries, as compared with 62% in 1995. The countries with the largest number of people with diabetes are, and will be in the year 2025, India, China, and the U.S. In developing countries, the majority of people with diabetes are in the age range of 45-64 years. In the developed countries, the majority of people with dia- betes are aged ^65 years. This pattern will be accentuated by the year 2025. There are more women than men with diabetes, especially in developed countries. In the future, diabetes will be increasingly concentrated in urban areas. CONCLUSIONS — This report supports earlier predictions of the epidemic nature of dia- betes in the world during the first quarter of the 21st century. It also provides a provisional pic- ture of the characteristics of the epidemic. Worldwide surveillance of diabetes is a necessary first step toward its prevention and control, which is now recognized as an urgent priority. Diabetes Care 21:1414-1431,1998 I n 1993, the World Health Organization (WHO) Ad Hoc Diabetes Reporting Group published standardized global estimates for the prevalence of diabetes and impaired glucose tolerance in adults, based on data from 75 communities in 32 countries (1). These estimates provided, for the first time, comparable information on the prevalence of abnormal glucose tolerance from many populations worldwide. How- ever, they did not meet the needs of those who frequently refer to the WHO diabetes From the Division of Noncommunicable Diseases (H.K.), World Health Organization, Geneva, Switzerland; the Prudential Center for Health Care Research (R.E.A.), Atlanta, Georgia; and the Division of Endocrinology and Metabolism (W.H.H.), Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan. Address correspondence and reprint requests to Dr. Hilary King, Division of Noncommunicable Dis- eases/DIA, 1211 Geneva 27, Switzerland. E-mail: kingh@who.ch. Received for publication 24 December 1997 and accepted in revised form 5 May 1998. Abbreviations: EME, established market economies; FSE, former socialist economies of Europe; LAC, Latin America and the Caribbean; MEC, Middle Eastern crescent; OAI, other Asia and islands; SSA, sub-Saha- ran Africa; WHO, World Health Organization. A table elsewhere in this issue shows conventional and Systeme International (SI) units and conversion factors for many substances. program for information on the number of people with diabetes in a particular coun- try/community, nor did they take account of future trends in the burden of diabetes. Therefore, a further study has now been undertaken that links data from the global database collected by WHO with demographic estimates and projections issued by the United Nations to estimate the number of people with diabetes in all countries of the world for three points in time, i.e., the years 1995, 2000, and 2025. In addition, the data have been analyzed in terms of certain additional parameters, such as sex ratio, urban-rural ratio, and the age structure of the diabetic population. The principal purpose of the project was to assemble numerical estimates and projections for the frequency of diabetes in all countries as a primary source of infor- mation and as an aid to planning health care and public health interventions in WHO's member states. RESEARCH DESIGN AND METHODS — This study is based on a set of 5-year age- and sex-specific estimates of diabetes prevalence from rural and urban areas of various countries. Criteria for inclu- sion were 1) a valid and apparently unbi- ased population sample and 2) a diagnosis of diabetes made according to the recom- mendations of recent WHO expert groups (2,3), i.e., a venous plasma glucose concen- tration of ^ 11.1 mmol/1 (or its equivalent) 2 h after a 75-g oral glucose challenge. Stud- ies using only fasting blood glucose testing were excluded. The estimates were drawn from the studies listed in the earlier report (1) with the addition of new survey data from China (4), Indonesia (5), Japan (6), Pakistan (7), and Uzbekistan (8). These data were then applied to demographic esti- mates for the world's population issued by the United Nations Population Division (9). In accordance with United Nations convention, Europe (including the former socialist economies), North America, Aus- tralia, New Zealand, and Japan were con- sidered "developed" countries, with all other countries designated as "developing" countries. For regional groupings, the aggregations proposed by the World Devel- opment Report 1993 were adopted (10). 1414 DIABETES CARE, VOLUME 21, NUMBER 9, SEPTEMBER 1998