Diabetes Case Study/Role Play
Roles:
1. Calvin (boy with diabetes)
2. Lena (mother)
3. Mrs. Perry (teacher)
4. Dr. Finkel (physician)
5. Zach (Lena’s husband)
6. Narrator
PART 1:
Narrator: This scene takes place in a first grade classroom.
Calvin: Mrs. Perry, can I go to the bathroom?
Mrs. Perry: Come here. (In a whispered voice so that the whole class cannot hear.) Calvin this
is the fourth time today you have asked me. Why are you drinking so much water?
Calvin: I am just soooooooo thirsty.
Mrs. Perry: Do you drink this much on weekends or are you just trying to waste my class time?
Calvin: I drink this much. At Jake’s party I drank a whole gallon of root beer. The grown-ups
thought that was too much.
Mrs. Perry: Whoa, that is a lot. I’ve noticed you’ve been slouched and tired in your seat all day
too. You have not been paying attention recently the way you used too. Are you tired?
Calvin: Yeah, I guess. I didn’t want to come to school today, but my mom said “tired” is not a
good reason to miss first grade.
Mrs. Perry: Okay, I’ll let you go to the bathroom, but I want you to stop at Nurse Robbie’s
office on your way back with a note I am going to give you.
Narrator: Mrs. Perry knows a family with a child who has diabetes. These symptoms may be
nothing, but they are reminding her of the other family’s story. She wants the nurse to call his
parents.
Narrator: The next afternoon, Calvin is with his mother, Lena, visiting the pediatrician, Dr.
Finkel. Dr. Finkel is performing a finger prick to get blood from Calvin.
Calvin: Ouch!
Dr. Finkel: Okay, that’s it. Let’s read it….hmmm…uh…okay.
Lena: Dr. Finkel, is everything okay?
Dr. Finkel: Well, I am measuring his glucose levels and he is at 585 miligrams per deci-liter.
Lena: I can see from your face that this number is not right. Is it too high or too low?
Dr. Finkel: Too high. Combined with his thirst, frequent urination and recent lethargy, I will
likely be making a diagnosis of juvenile diabetes known as type I diabetes. Chronic
hyperglycemia or “high sugar” levels is what we mean when we say diabetes.
Calvin: Ooh, Mom, isn’t that what great uncle Charlie has?
Lena: Yes, honey, it is similar. Why don’t you go play in the kid area so I can finish talking with
Dr. Finkel.
Calvin: Okay, Mom. Can I play with their Wii?
Calvin’s mom: Sure, honey.
Calvin: Cool!
Narrator: Calvin walks out.
Lena: Aren’t you rushing to conclusions, Dr. Finkel? He just ate a lollipop while we were
waiting, so maybe that is why it is high?
Dr. Finkel: Sure Lena, that might contribute to what I am seeing, but a normal person, when
randomly tested even after eating, should not have a glucose reading above 200.
QUESTIONS:
1: What allowed Dr. Finkel to make a diagnosis of diabetes?
2. Is Dr. Finkel rushing to conclusions? What else might you want to know?
3. What are the possible reasons you can think of for why there is too much sugar in his
blood? Where should it be?
PART 2:
Narrator: Calvin’s mom, Lena, has been voraciously reading biology textbooks and websites to
understand her son’s condition. She wants to learn the biology before she talks to the doctors
again. She tries to explain it to her husband, Zach.
Lena: So Calvin has too much glucose in his blood because some of his cells can’t take it in
from the blood. It is as if Calvin is missing the key that will let the glucose through a locked
door.
Zach: So what is the key in your analogy? What is he missing that we have?
Lena: Insulin! I found an animation about how insulin works on muscle cells. If insulin is bound
to the surface of the muscle cell, glucose transporters become available on the surface for
glucose transport. See, glucose can’t simply diffuse into the cell without its transporter because it
is a bulky molecule. So with the insulin present, this is the key that opens the door for glucose.
Lots of insulin available means that cells can take up lots of glucose. And the liver and muscles
can even store it in long chains.
QUESTIONS:
4. How do muscle cells and liver cells store the excess glucose in long chains?
5. What would you predict would happen to muscle cells if there was no glucose available
to them?
6. Insulin is protein secreted from pancreatic cells. Describe the normal secretory pathway
for proteins (i.e. Where is the protein made and in what compartments does it pass
through?)
7. How does the process differ from your previous answer if a protein was meant to stay
inside the cell to function?
8. A cell is often compared to a protein factory. Let’s think about a shoe factory. What
kinds of problems can arise so that shoes don’t get made at this factory? What would these
problems be analogous to in the cell? (For example, shoes might not get made if the
blueprint or design for the shoe were lost. This might be analogous to mRNA not being
made as a set of instructions for making the protein.) Come up with a different analogy for
some other aspect of production.
9. What are some possible reasons as to why Calvin would not be producing insulin?
PART 3:
Narrator: Several years later. Calvin is in middle school now.
Lena: Calvin, clear your dinner plate and head upstairs – you still have to do homework and
don’t forget to check your glucose levels and adjust your insulin pump.
Calvin: Mom, I know. I know. I have to adjust the insulin levels up after I eat. I KNOW! You
always tell me what you read, “Insulin levels peak 10 minutes after eating.”
Narrator: Calvin runs upstairs. He is gone for some time.
Calvin: (Calling worried) Mom, can you come here? I don’t feel well.
Lena: What’s the matter, honey? Calvin! You are so sweaty and you are trembling. Did you give
yourself too much insulin? Let me check your glucose? Oh my. 45 mg/dL. Too low. Quick!
Drink some orange juice, let me get it.
Narrator: Lena runs back with the juice
Calvin: (After drinking) I am feeling a little better. I thought I was about to pass out – my head
felt funny.
Lena: You were. Too much insulin means that your cells – like your muscles – took up too much
of the glucose and stored it. But your brain cells don’t respond to insulin and don’t have any
glucose on reserve. Brain cells can’t store glucose. Your brain cells were desperately running out
of fuel until I gave you some orange juice.
Calvin: Thanks, Mom. Low blood sugar is scary. I guess I need to be more careful about taking
care of myself.
Lena: Yes, low blood sugar is scary. And so is high blood sugar. We have to be careful to
control this with your insulin. Remember all the effects of high blood sugar over a lifetime.
Uncle Charlie, unfortunately, has many of those effects – like his blindness, foot ulcers, and
kidney problems.
Calvin: Yeah, that is awful. I am learning how to take care of me as well as you take care of me.
QUESTIONS:
10. Compare and contrast hyperglycemia and hypoglycemia.
.
11. Why do you think healthy individuals are able to fast for many hours without becoming
hypoglycemic? What controls do you think are in place in your body?
12. Individuals with type II diabetes have normal insulin levels, but the muscle and liver
cells cannot respond to the insulin present in the bloodstream. What would you expect the
symptoms to be?
13. Do you know anyone with diabetes? Is there someone in your classroom with diabetes?
See if they might be willing to share their experiences.
CASE STUDY ANSWER KEY:
1. What allowed Dr. Finkel to make a diagnosis of diabetes?
Combined thirst, frequent urination, and tiredness, plus the high glucose reading. (These
symptoms can develop quickly and may also include extreme hunger, weight loss and blurred
vision. The extreme thirst he feels has to do with osmotic balance – too much sugar in the blood
means water from the tissues will follow into blood. This leaves tissues dehydrated and the
feeling of thirst comes over.)
2. Is Dr. Finkel rushing to conclusions? What else might you want to know?
He only has one glucose reading. While the combined ideas point to diabetes, he might want to
have more long-term monitoring and take a more detailed history of Calvin to see how long these
symptoms have been going on. He could also do a fasting test (usually 8-10 hours of fasting).
This should not be above 99 mg/dL for a normal individual. Random testing (not fasting) would
be between 70-150 mg/dL for a normal individual.
3. What are the possible reasons you can think of for why there is too much sugar in his
blood? Where should it be?
Too much of any biological molecule in the body could mean that there is either too much
consumed/produced or not enough being used/degraded. For example in the metabolic disorder
PKU, the amino acid phenylalanine (obtained from the diet) cannot be metabolized and builds up
in the tissues in the form of phenylpyruvate. Students may suggest that Calvin is taking in too
much sugar in his diet. Alternatively, maybe his body cannot use the glucose in his diet and this
is why the levels are high. In diabetes, glucose from the diet cannot be effectively removed from
the blood. As it builds up in the body, the blood glucose levels rise and it is detected in urine.
Glucose should normally be moved into cells needing to make ATP via cellular respiration.
Muscle cells need the glucose to make ATP but cannot take the glucose in. Cells not making
ATP leads to the fatigue and weight loss.
4. How do you think muscle cells and liver cells store the excess glucose in long chains?
Condensation reactions with glucose  glycogen. (Here is a good place to make connections
back to your macromolecule discussion.)
5. What would you predict would happen to muscle cells if there was no glucose available
to them?
The cells cannot make ATP or cellular energy efficiently. The muscles will be forced to use
alternate molecules to make glucose: 1) from amino acids (the body starts breaking down its own
proteins) or 2) from glycerol (a component of triglycerides.)
6. Insulin is protein secreted from pancreatic cells. Describe the normal secretory pathway
for proteins (i.e. Where is the protein made and in what compartments does it pass
through?)
Take time to lecture here if needed. A mRNA (instructions for making a protein) exits the
nucleus and moves to a ribosome. The protein that is translated is spooled into the RER where it
folds. It is packaged in a membrane-bound vesicle that buds from the ER and fuses with the
Golgi. Here, proteins are further processed chemically. A vesicle containing the protein then
buds from the Golgi and fuses with the plasma membrane. The protein is then released outside
the cell.
7. How does the process differ from your previous answer if a protein was meant to stay
inside the cell to function?The protein would be made from a mRNA at a ribosomes in the
cytosol that does NOT associate with the RER (The newly synthesized protein lacks a signal
sequence that secretory proteins require for RER association).
8. A cell is often compared to a protein factory. Let’s think about a shoe factory, what
kinds of problems can arise such that shoes don’t get made at this factory? What would
this problem be analogous to in the cell? (For example, shoes might not get made if the
blueprint or design for the shoe were lost. This might be analogous to mRNA not being
made as a set of instructions for making the protein.) Come up with a different analogy for
some other aspect of production.
There are lots of possible creative ideas here. There is no energy or money to run the factory
(not enough ATP). The factory was destroyed in a fire. The equipment that adds laces is broken,
so the shoes made are useless (The Golgi did not chemically process the protein correctly). The
factory burns down (the cell is destroyed).
9. What are some possible reasons you can think of as to why Calvin would not be secreting
insulin?
There are numerous ideas here. Let the students explore many ideas and be scientists.
There may be a gene mutation such that protein cannot be transcribed or the mutation produces a
severely truncated or altered insulin. The insulin might not have made it into the RER and
remains in cytosol.
Although many diseases are the result of problems with getting a protein out of the cell,
with type I diabetes the beta pancreatic cells are destroyed likely by autoimmune process. (This
would be analogous to the factory being burned down).
10. Compare and contrast hyperglycemia and hypoglycemia.
Hypo = low blood sugar. Hyper = high blood sugar.
For severe hypoglycemia, (unconsciousness) the person would need a glucagon injection, some
diabetic individuals carry these with them. Glucagon would liberate glycogen stores and
immediately put glucose into the blood stream. Glycoegn is hydrolyzed to glucose monomers.
11. Why do you think healthy individuals are able to fast for many hours without becoming
hypoglycemic? What controls do you think are in place in your body?
This is the concept of homeostasis: keeping internal glucose levels within a normal range. When
blood glucose levels fall to low, the hormone glucagon is normally secreted into the blood (from
the alpha cells of the pancreas). This tells the liver to hydrolyze glycogen and release glucose
into the blood. The glucose can be taken up from the blood for the cells that need it, provided
there is some insulin to “let the glucose in.” (People with type I diabetes typically still have alpha
cells to produce glucagon; they are missing beta cells that produce insulin.)
12. Individuals with type II diabetes have normal insulin levels, but the muscle and liver
cells cannot respond to the insulin present in the bloodstream. What would you expect the
symptoms to be?
(The distinction with muscle and liver is made here because neurons are mainly insulin
independent for glucose uptake.) Type II diabetes presents as “insulin resistance.” The symptoms
are similar to type I diabetes. Type II diabetes is the more common type in adults and a
significant risk factor is obesity.
13. Do you know anyone with diabetes? Is there someone in your classroom with diabetes?
See if they might be willing to share their experiences.