EPIDEMIOLOGY OF DIABETES – ITS HISTORY IN THE LAST 50 YEARS

Professor Paul Zimmet, AO, MD, PhD, FRACP, FRCP(UK)

International Diabetes Institute, Melbourne, Australia

AbstractThe application of epidemiology to the study of diabetes mellitus has provided new insights into many aspects of this major public health problem including its natural history, prevalence, incidence, morbidity and mortality in diverse populations around the globe.

“I, too, have not seen it in the West, nor did any of my teachers under whom I studied mention that they had seen diabetes. However, here in Egypt, in the course of approximately ten years, I have seen more than twenty people who suffer from this illness.”

“Diabetes mellitus was seldom seen in “cold” Europe, whereas it was frequently encountered in “warm” Africa.”

MAIMONIDES - THE FIRST DIABETES EPIDEMIOLOGIST?

(1135-1204AD)

Introduction (cont.)In between sifting and synthesizing this voluminous information, West made a number of insightful and noteworthy suggestions with regard to the future direction of diabetes research, and set a number of challenges for his colleagues. He was also somewhat prophetic in predicting some of the issues that are under critical (and sometimes not so critical) debate today, particularly with respect to classification and criteria of the diabetes syndrome.

The first WHO Expert Committee on Diabetes Mellitus

was convened in Geneva in 1964 (6). The report of this group includes one of the first attempts at international consensus on a classification. While there have been a number of sets of nomenclature and diagnostic criteria proposed for diabetes including the 1964 attempt, no systematic categorization existed until just over 20 years ago. The contemporary classification of diabetes and other categories of glucose intolerance, based on scientific research on this heterogeneous syndrome, was developed in 1979 by international workgroups, the National Diabetes Data Group (7) of the National Institutes of Health, USA, and the WHO Expert Committee on Diabetes in 1980 (8).

Yet another important milestone was the first WHO/IDF training course in epidemiology of diabetes held in Cambridge UK in 1980. This was the first of several courses that have boosted the numbers of diabetologists from many countries around the globe becoming “infected” and joining the epidemiology ranks. One of my sole recollections of the first course was missing the televising of the Royal Wedding of Prince Charles and Princess Dianne as a result of being hauled off by the notable anti-Royalist, John Jarrett, to be thrashed on the tennis court!

Another major initiative in diabetes epidemiology, spurred on by Ron LaPorte and the Pittsburgh Group in the early 1980s, was the concept of diabetes registers. Their creativity and enthusiasm saw over the next decade or so the development of Type 1 diabetes and insulin treated diabetes registers established in many countries. I estimate the number of such registers now exceeds well over 200. These registers were not only important in terms of descriptive epidemiology but form the basis of investigative studies on both the genetic and environmental risk factors for Type 1 diabetes.

Major early epidemiology studiesClearly the Pima Indian (11) and our Pacific Island studies (12) have been of inestimable value in understanding not only the aetiology and natural history of Type 2 diabetes but also the development of approaches for prevention. Other important early studies include Bedford (Harry Keen), Whitehall (John Jarrett), San Antonio Mexican-American (Michael Stern), San Luis Valley Hispanic (Richard Hamman), Rancho Bernardo (Elizabeth Barrett-Connor), Japanese American (Wil Fujimoto) and the Paris Prospective (Eveline Eschwege).

Estimated global prevalence of type 1 and type 2 diabetes

A personal perspective of an introduction to epidemiology

In the early 1970’s I was completing a PhD in the Department of Biochemistry at Monash University in Melbourne. We had a theory that fragments of human growth hormone might be involved in the regulation of the insulin sensitivity and we developed biological assays for a number of peptides (16). Intuitively I thought that the only way to show their real significance would be to test them in an epidemiological framework!!

Harry Keen and John Jarrett in the early 1970’s

A personal perspective of an introduction to epidemiology (cont.)

It was then that I had my first experience of the difficulties and logistics of undertaking a survey thousands of miles from home, on a remote island, with virtually no back-up facilities and with untrained staff. Nauru was a seven hours’ flight from Melbourne and there was only one flight a week on Air Nauru (but they did serve Chateau Mouton Rothschild with the meals!).

Where to now?I have to confess to a certain degree of cynicism about the relevance most animal models being used to understand the aetiology of diabetes and in particular Type 1 diabetes. It has always been my belief that the epidemiological studies in human populations provide the best direction for such research and the development of new hypotheses. This view may well upset some of my laboratory-based colleagues.

Conclusions

Epidemiology has come a long way since those early years. The study of epidemiology involves much more than number counting.