AGENCIES ATTENTIVE to the health of Americans have been increasingly concerned about the rising number of diabetics in the adult population. A recent collaborative study initiated by the Centers for Disease Control and Prevention (CDC) has found the following: The prevalence of diabetes mellitus in the United States is rising rapidly, and the presence of diabetes mellitus substantially increases the risk of coronary heart disease and cerebral stroke, particularly in diabetic adults younger than 64.

In Americans between 35 and 64 years, the CDC study noted that coronary heart disease is found in 3.6 percent of non-diabetics but in 18.4 percent of diabetics; stroke is found in 1.2 percent of non-diabetics but in 5.9 percent of diabetics. The presence of diabetes mellitus, therefore, increases the likelihood of either coronary heart disease or stroke (or both) almost fourfold. This disparity in risk between diabetics and non-diabetics prevails beyond the age of 64, though less dramatically. Thus, in non-diabetics older than 75, 20.6 percent are burdened with coronary heart disease, while in diabetics older than 75, 35.3 percent have coronary heart disease.

In general, blood-vessel diseases of the heart and brain impose a substantially greater burden on the diabetic segment of the population than on the non-diabetic.

Some people may contend that the apparent rise in incidence of diabetes represents an increasingly fastidious medical coverage of the general population, not a true rise in incidence. Few, however, would doubt that some 18 million Americans are afflicted with diabetes mellitus. And Sir George Alberti, president of the British Royal College of Physicians, has predicted that the number of diabetics in Britain will increase in the next decade by 50 percent.

Has diabetes always been this common? Was it even present centuries ago? And if so, how did the ancients -- unencumbered by the revelatory gifts of laboratory-based medicine -- ever recognize it?

There is a Third Dynasty (Egyptian) papyrus, about 1550 BCE, that mentions a rare disease characterized by excessive urination (polyuria) and unremitting weight loss. The great Aretaeus (30-90 CE), the Greek physician who practiced in Cappadocia, described a disease with unremitting thirst (polydipsia), polyuria, and weight loss (he called it a melting of the flesh); because of the polyuria, he provided it with a name: diabetes, from the Greek meaning a flowing through. Galen (131-201 CE) then offered clear descriptions of the disease, noted its rarity (he claimed to have seen only two cases in his long career), and declared -- mistakenly -- that it was an affliction of the kidneys.

Diabetes, if mentioned at all, remained a rarely discussed disorder through the Middle Ages. Avicenna, the great Arabist physician, provided the first comprehensive description of the disease, including its remorseless clinical course and its many complications, such as blindness and loss of libido.

There were few objective parameters of health and disease during those centuries when medicine was struggling merely to identify, let alone cure, human disease. The clinical thermometer, for example, was not devised until the 19th Century. And so physicians sought something to examine besides the anxious faces of their patients. The art -- not yet science -- of urine examination then came into being. It was called uroscopy and it consisted of peering at a glassful of the patient's urine, preferably in sunlight, seeking such variables as volume, color, murkiness, sediment, and odor. Some anonymous practitioner, more curious -- or perhaps more bold -- than his colleagues, took to tasting the urine specimens of his patients. And sooner or later he encountered a urine that had a very sweet taste (representing the excess sugar flowing into the urine of the diabetic). Thus the disease came to be known as diabetes mellitus, from the Latin word meaning honey.

Paracelsus (1493?-1541), the irascible Swiss physician with the wonderfully long full name Theophrastus Bombastus von Hohenheim, examined a large number of diabetics and concluded that it was a serious systemic disease, clearly life-shortening.

By the early 19th Century, objective chemical tests were formulated to detect the presence of sugar in the urine. Many therapies were endorsed, but in the absence of understanding the underlying cause of the disease, none proved effective. During the Franco-Prussian War (1870-71), however, a French physician named Bouchardat noted a curious happening: Paris, then under German attack, instituted food rationing for its besieged citizens. Bouchardat's diabetic patients, on substantially reduced diets, all improved somewhat. And so it was seen that some diabetic conditions could be marginally controlled by severely reduced caloric intake.

In 1889 Oskar Minkowski and Joseph von Mering, in northern France, noted that removing the pancreas in experimental animals resulted in a diabeticlike state. The pancreas, considered solely as an organ supplying digestive juices, was then suspected of possessing further functions, including the regulation of sugar metabolism. Preceding this discovery was the investigation of the microscopic structure of the pancreas by a medical student named Paul Langerhans. He verified that most of the organ was indeed composed of cells generating digestive juices. But scattered around were little islands of cells, the functions of which were then unknown.

In 1920, an American physician named Moses Barron published a brief paper suggesting that impairment of those pancreatic cells described by Langerhans was the root basis for diabetes mellitus. Dr. Frederick Banting, of Toronto, read Barron's paper and began the critical experiments showing that extracts of pancreas yielded a substance that, when introduced into diabetics, controlled the disease.

This elusive substance was shown to be an essential hormone, later named insulin (since it originated in Langerhans's "islands" of cells). In 1923 Banting and one of his colleagues were awarded the Nobel Prize.

The life of the diabetic -- once perilous and short -- while still beset with organic complications, is now vastly safer and certainly prolonged.

Stanley M. Aronson, M.D., a weekly contributor, is dean of medicine emeritus at Brown University (smamd@cox.net).