CASE TEACHING NOTES
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Diabetes mellitus is a complex metabolic disorder that affects 16 million Americans and causes 200,000 deaths annually. When it occurs in children and teenagers, it is caused by a failure of the beta cells of the Islets of Langerhans. The immune system attacks the islets cells, which are located in the pancreas, and destroys their capacity to produce insulin. Without insulin, sugar from the blood cannot enter the body cells, which then "starve to death." Since the disease runs in families, there is presumptive evidence that it has a genetic basis, although a person's diet plays a significant role in whether a full-blown case develops. Andrea developed this disorder when she entered puberty, the normal time when diabetes occurs in many people, hence the name, "juvenile diabetes." This term has been replaced in the literature by the less descriptive term, "Type 1 diabetes."
This case is suitable for a physiology class when the subject matter turns to metabolism and hormonal control. There is a companion case on our website, "Morgan: A Case of Diabetes," dealing with "Type 2 diabetes" that focuses on Native Americans, among whom the disease has reached epidemic proportions. Type 2 diabetes is a much more common disorder, especially among adults (90% of all diabetics are Type 2); sufficient insulin is produced but the cells of the body are insensitive to its effects, so the blood sugar cannot enter the body's cells. Together, Type 1 and Type 2 diabetics are two to four times more likely to suffer from heart disease and stroke than normal individuals. Diabetes is the seventh leading cause of death in the United States. It is the leading cause of blindness, kidney disease, and non-traumatic leg amputations.
The overriding issue in the case is the function of the endocrine glands in the regulation of metabolites. Obviously, this may be addressed by focusing on the function of the hormones one at a time, the critical ones being insulin, glucagon, and adrenal cortical steroids. The role of cellular receptors is a logical topic as well. All of these are covered in any physiology book. It is useful to have students draw a concept map of these interactions or to have them draw diagrams of endocrine feedback loops.
Another feature of the case, if the instructor wishes to pursue it, is the structure of the eye. For those teachers who wish to examine this topic, this case is an excellent entrée into this territory. Also, the topic of autoimmune disease may be explored if the instructor wishes to examine how the immune system works and what happens when it goes awry.
But the case is much richer than the obvious issues above. Discussion can easily move in the direction of preventative measures, diet control, and exercise as well as the various types of therapies being tried. Insulin delivery methods have greatly changed since Andrea's day; they include insulin pumps and oral delivery methods. Also, the use of islet cell transplantation, pancreas transplantation, the future use of stem cells, and genetic engineering are all excellent topics for exploration. For nursing students, there are many opportunities for discussions on patient care and community health issues.
This case can easily be handled by the discussion method. Just think of the major basic science topics that can be explored: metabolism, hormones, cell receptors, eye anatomy, immunology, plus the clinical aspects of the case including nutrition, exercise, stem cell research, transplantation, drug delivery systems, genetic engineering, and health care. One hardly knows where to start. But, depending on the course, the opening question by the teacher should get to the facts first, before the students start talking about possible solutions and therapies.
The case can be set up to be a directed case. Here there should be a series of questions that the teacher appends to the case. These would be questions that s/he expects the students to answer in written form before they come to class. The papers would be collected when the students enter the classroom. The teacher would then run through the questions and call upon various members of the class to give their answers and explain them in detail. If the students don't respond accurately, the instructor will know that the student is not adequately versed in the subject and will adjust the grades accordingly, regardless of what kinds of answers they placed on their answer sheet before the class began.
If this case were run in the problem-based learning mode, the case could be broken in the middle, where the father finishes typing the paper. The students in their permanent groups would have to decide what the learning issues were and go find the necessary information on the Internet or in printed material to answer their concerns. Surely, the learning issues would include topics of diabetes, hormones, insulin, pancreas, nutrition, etc. The second part of the case would follow and I would expect students to focus on the eye, blindness, cardiovascular disease, different possible treatments, and whether Andrea should have undergone surgery.
Acknowledgements: This case study was developed with support from The Pew Charitable Trusts.
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Date Posted: 2/12/02 nas
