Diabetes mellitus

Let’s start with some basics.

Hormone: A chemical or protein released by a cell in one part of an organism that travels and binds to cells in another part of the organism.   This chemical is transferring information.  It is acting like a letter sent through the mail.  Upon receiving the letter, you have new information and can act accordingly.  Hormones are one way that cells “talk” to each other and convey information.

Insulin: a hormone that is released to control the amount of glucose in your blood.  The food we eat is full of nutrients that our body needs.  So, after we eat a meal, our body breaks down the food into small pieces that it can use to rebuild things.  

Glucose: A sugar that is really important to biological processes.  Following a meal, your food is broken down into a lot of glucose molecules which are eventually absorbed into the blood stream.  

          

                Okay… we got a lot pieces.  Let’s fit it all together.  After eating a meal and your body gets a lot of glucose from it.  All the glucose is put in your blood stream so it can be delivered to the cells around the body that need some fuel.  As I told you in the CentralDogma post, cells have the protective plasma membrane around them to keep things out.  How does the glucose get in?  Insulin.  Your body recognizes that the glucose level in your blood is high (also called your blood sugar level) so insulin is released to the blood stream.  Insulin then travels around, binds to your cells and basically says “There’s a lot of glucose out here – let it in!”  Glucose then goes inside your cells to be further broken down to energy and carbon dioxide (CO₂, which we breathe out).

                Whew.   

                So what is diabetes mellitus?  The loss of or resistance to insulin.

                I worked in a diabetes laboratory as a research technician for two years and became familiar with several different versions of the disease.  I’ll try to briefly describe them here.

Type 1 Diabetes (aka Juvenile Diabetes): Insulin is produced by the beta cells in the pancreas.  In Type 1 diabetic patients, these beta cells are lost.  No beta cells = no insulin in the body.  Children typically presented with the disease, which is how it got the name of Juvenile Diabetes, however it is possible to develop it as an adult so it is commonly referred to as Type 1 now.

Type 2 Diabetes: Insulin is still made in the body (at either the same or lower levels) but the body no longer responds to it.

Gestational Diabetes: During pregnancy, the body either inadequately makes insulin or stops responding to it.  This is somewhat similar to Type 2 Diabetes.  A very low percentage of pregnancies are affected.  

MODY (Maturity-onset Diabetes of the Young): A genetic mutation limits the amount of insulin that can be made by the body.  Symptoms, which are often mild, manifest in adolescence or early adulthood.

                Please be aware that these are not the only kinds of diabetes.  Other rarer kinds or more specified problems of diabetes further breaks down the names of the disease.  These are the kinds I was most familiar with but I don’t pretend to be an expert.  Feel free to research the topic!

                Common signs of diabetes are increased thirst, hunger and urination.  One way test for diabetes is to determine if glucose is present in the urine.  When insulin can’t do its job, then the glucose remains in the blood stream and is eventually excreted.  Since glucose is a precious energy source for the body, excretion should never happen.  If the body has no current use for the glucose, it will store it as fat instead of eliminating it.  Just like if your wallet has extra $20 bills (because that always happens), you wouldn’t drop the excess on the street!  Instead, you’d put it in the bank.  Several other blood tests and whatnot also exist to more accurately determine what is going on.

                Literally, this topic can now go a hundred different ways.  I could discuss how doctors have tried pancreatic beta cell transplants to cure patients or how Type 2 diabetes is most common in industrialized countries.  An interesting topic may also be current research on gestational diabetes since many of my readers are of my own age.  Clearly, this may have to turn into a series.

                However, with my last little bit here, I’d like to step away from the research and discuss the history of this disease.  Before injectable insulin became available to Type 1 diabetics in 1921, diabetes was a devastating problem.  People suffered and starved due to their inability to uptake glucose from the blood.  As a technician, I remember seeing a presentation which embedded a movie of diabetic children.  They were gaunt with hallow faces and serious eyes.  They looked traumatized and desperate.  Left untreated as they had to be, they died while suffering from blindness, starvation, and kidney problems.  It was a haunting presentation.

                As early as 1552 BC, the Egyptians recognized frequent urination as a symptom for a weird disease they named emaciation.  In Ancient Greece, the disease gained the title “diabetes” from the Greek word meaning siphon.  Doctors felt the disease was siphoning or melting off the patient’s very limbs.  By 1675 AD, doctors noted that urine of diabetics tasted sweet so they added the word “mellitus” meaning honey.  (For real, they employed people to taste urine and determine its sweetness.  Who wants that job?)  Finally, after several studies surrounding the pancreas and diabetes, Frederick Banting and his collegues successfully treated a diabetic patient with insulin.  They were awarded the Nobel Prize in Medicine in 1923.

                I do not know any diabetics personally, but I had a class immediately following lunch during my freshman year of college.  A senior in that class would walk in, take out a large kit, test his blood sugar, measure out insulin and inject himself before the professor arrived.  I watched him every day and he was so nonchalant about it.  Sadly, I have no further personal stories about diabetes.  If anyone would like to share some, please feel free!

REFERENCES

Alberts et al. “Molecular Biology of the Cell, 4^th Edition.”  Garland Science, New York, New York. (2002).

History of Diabetes: http://www.everydayhealth.com/diabetes/understanding/diabetes-mellitus-through-time.aspx

 

Me, myself and I