Samuel Gonzalez, an obese 58-year-old Hispanic man presents to his primary care provider (PCP) feeling constantly tired and sleepy. When questioned, he complains he is drinking more soda than usual because he feels thirsty all the time and also reports blurred vision and decreased sensation in his feet. As a construction worker, he wants to feel better so he can do his job.
What additional questions should be asked about Samuel’s symptoms? What lab tests would you expect to be ordered to evaluate his problems? What diagnosis would you expect?
On brief history alone, could you have identified classic risk factors for diabetes mellitus? What diagnostic criteria would confirm your suspicions? Once the diagnosis of type 2 diabetes mellitus (T2DM) is confirmed, what are the next steps in helping Samuel manage his chronic condition? At the completion of this course, you will be able to guide Samuel, and countless others with T2DM, to better health.
In the first five minutes that you are reading this course, two people will die of diabetes-related causes and fourteen adults will be newly diagnosed (CDC, 2014). T2DM is the seventh leading cause of death in the United States (the number one cause is cardiovascular disease). More than 29.1 million people have been diagnosed with diabetes mellitus (CDC, 2014). That’s about 1 in every 10 Americans. The disease has become a new epidemic in our country; however, it is not a new disease.
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Diabetes mellitus is an ancient disease, the clinical symptoms of which were identified by the ancient Egyptians more than 3000 years ago (Ebbell, 1937). The Greek word diabetes means “to siphon through” and describes polyuria (excess urination), which is a classic symptom of hyperglycemia. Centuries after diabetes was recognized, the term mellitus, which means “sweet honey,” was added to describe the sweet urine identified with chronic hyperglycemia (Ahmed, 2002).
For centuries there was no known reversal of symptoms for diabetes. Treatment strategies varied from starvation to overfeeding, bleeding, and even riding horseback to stop the polyuria. During the opium trade, patients were treated with opium (known as “doping”), which didn’t cure the disease—but the patients probably didn’t care! None of these treatments cured diabetes because for centuries the cause for the sweet and high volume of urine was unknown.
Then in 1673 a German scientist removed a pancreas from a dog and induced diabetes mellitus, creating the same symptoms of excessive thirst and polyuria. Nearly two centuries later unique pancreatic cells were identified as the source of sugar problems in the blood and urine. The juicy substance of the pancreas, distinct from the exocrine juices, was named insulin (Latin for “island”) in 1916 (Pratt, 1954).
*Islets of Langerhans: Insulin-producing cells in the pancreas, discovered by and named for the scientist Paul Langerhans (1847–1888).
Once the lack of insulin was identified as the cause for diabetes mellitus, several scientists worked to extract, refine, and administer the substance. A German scientist, Georg Zuelzer (1870–1949), successfully injected the pancreatic extract into eight patients with diabetes; however, his research was halted due to demands that he work on weaponry for World War I. Similarly, a Romanian physician, Nicolas Paulescu (1869–1931), injected the pancreatic solution into the jugular veins of diabetic dogs, reversing symptoms, but his research was halted by the same world war (Pratt, 1954).
A continent away from European researchers, Canadians Frederick Banting (1891–1941) and Charles Best (1899–1965) isolated the insulin molecule and received credit for the discovery of insulin in 1921 (Pratt, 1954). They successfully filed a patent and contracted with Eli Lilly, a pharmaceutical company, to manufacture the newfound “medication.”
Scientists and physicians then began to understand the relationship between insulin and sugar in the bloodstream. Insulin was identified as an anabolic hormone, which builds the body and allows nutrients that are eaten to enter the body cells for growth and life. So, over many millennia and through the contributions of numerous physicians and scientists, we finally understand the powerful connection between sugar and insulin.
Sugar comes from the carbohydrates we eat and it requires insulin in order to move from the blood into the cells of the body and be used as energy. Without insulin, or minimally sufficient amounts, sugar remains in the bloodstream causing hyperglycemia, which is the hallmark symptom of diabetes mellitus (DM). Hyperglycemia causes high blood osmolarity (concentration of particles), which pulls water from tissues in an attempt to dilute the blood, causing polyuria and dehydration. The dehydration in turn causes polydipsia (excessive thirst) and the cycle of excess urination and dehydration continues.
Without the needed energy from glucose the cells may starve, and the individual may lose weight as the body breaks down fat and protein for alternate sources of energy. The resulting classic triple signs of diabetes are shown in the box below.
Classic Triple Signs of Diabetes
Walking through time together to learn about the millennia-old disease of diabetes mellitus helps us to appreciate how far we have come in understanding this growing epidemic.
Test Your Knowledge
The symptoms of diabetes mellitus were first identified:
Apply Your Knowledge
How does knowing about the history of diabetes improve your understanding of the disease and its treatment?