Yes, today we will be talking about Diabetes. Its probably the most common illness that I've seen all year long, so I thought I'd brush up on my knowledge, and try to explain in layman's terms to all of you. I tried my best to cover the pathophysiology, risks, symptoms, etc, but if you have any comments or questions, shoot me an email.
Lets get started...
Diabetes is a disease in
which the body cannot effectively control the levels of glucose, or sugar, in
our body. Glucose is one of the primary sources of energy used by all the cells
of our body, and therefore it is crucial that there is adequate control of
glucose levels at all times.
There are two main hormones
that are made by our body to control glucose levels. The pancreas secretes
glucagon to increase glucose levels, and secretes, insulin, a hormone that
helps glucose to enter cells of the body.
Normally, after a meal, the body senses the glucose levels in your
bloodstream and the pancreas produces just enough insulin in response to ensure
that the cells get the glucose. In diabetes, there is a defect in the way
insulin controls glucose levels.
There
are two types of diabetes, type I and type II. In type I Diabetes, the body
makes very little or no insulin at all. However, in type II Diabetes, the body
becomes resistant, or unresponsive, to the actions of insulin. Therefore, in both types, glucose is
not properly moving out of the bloodstream into the cells, and is building up
in the blood and being excreted in the urine without functioning as fuel for
our body.
DM Type I: This is an autoimmune
disease, in which the body’s immune system attacks and destroys the pancreatic
cells that produce insulin. Therefore, the body produces very little or no
natural insulin. This type of diabetes is generally seen in younger individuals
as this disease is thought to develop in genetically susceptible individuals.
Symptoms generally arise acutely and include, but are not limited to, increased
urination and thirst, unintentional weight loss, fatigue and even blurred
vision. It is crucial to recognize these symptoms quickly because life-threatening
consequences of high blood glucose levels may develop quite rapidly.
DM Type II: This form
of diabetes is most common, and generally develops in people over the age of
40. The pancreas is fully functional and makes adequate amounts of insulin in
this disease, however, the cells of the body become resistant to the effects of
insulin. The cause of this resistance is unknown. At first, the body increases
its production of insulin to overcome the resistance and control blood glucose
levels so they remain at a normal range. However, over the years, the pancreas
loses its ability make adequate amounts of insulin, and the glucose levels
build up in the blood and are excreted into the urine without serving as fuel
for the body. Symptoms will develop gradually over years, and include fatigue,
frequent thirst and urination, blurred vision, frequent infections, and slow
wound healing.
Diagnosis:
Fasting Glucose:
If the level of blood sugar after not eating for at least 8 hours is above 126
mg/dL. If levels are between 110 and 125 mg/dL, the patient is known to have an
impaired fasting glucose, meaning that they are at risk for developing diabetes
and its complications in the future.
Glucose Tolerance: After a patient drinks a liquid containing 75 grams
of glucose, and the blood sugar levels over the next two to three hours is
above 200 mg/dL. If levels are between 141 and 199 mg/dL, the patient is known
as having an impaired glucose tolerance, meaning that they at risk for
developing diabetes and its complications in the future.
Risk Factors
Unfortunately, anyone can
develop diabetes, however, certain risk factors put individuals at higher risk.
These risk factors can include family history if diabetes, age (insulin
production decreases with age), obesity and a sedentary lifestyle.
Symptoms
More commonly, the symptoms
of diabetes include increased thirst, increased urination, fatigue,
unintentional weight loss, excessive hunger. Sometimes, people experience
problems with vision, itchy skin and even cuts or infections that take longer
to resolve. If you are experiencing any of these symptoms, please call your
doctor. People who have not received medical attention often present with
complications such as heart attack, stroke, impotence, neuropathy, or retinopathy.
Complications
Hyperglycemia,
or increased blood glucose levels, has detrimental effects on the blood vessels
of the body and are a major source of morbidity and mortality in both type 1
and type 2 diabetes. Therefore, it is crucial to protect the body from
hyperglycemic states. The harmful effects of chronic uncontrolled diabetes can
be differentiated into macrovascular and microvascular complications.
High glucose levels can lead
to macrovascular complications by the process of accelerated atherosclerosis.
Atherosclerosis refers to a condition in which fatty substances, such as
cholesterol, build up in the walls of arterial blood vessels. The plaques in
blood vessels reduce the blood supply to specific regions of the body and
result in symptoms specific to the location of atherosclerotic plaques. The
exact mechanism is unknown, however many studies have shown that diabetes
results in increased direct injury to the walls of blood vessels, chronic
inflammation, and increased propensity for blood clots. Atherosclerosis can
manifest as:
- Coronary artery disease: results from atherosclerosis of the blood vessels supplying the heart, resulting in decreased delivery of oxygen and nutrients. Growth of the occlusion can result in chest pain, and even heart attacks, which are often “silent” in diabetic patients.
- Peripheral vascular disease: results form atherosclerosis and narrowing of blood vessels that supply the legs and feet. Symptoms include pain, weakness, numbness, chronic, non-healing sores, wounds, and ulcers.
- Cerebrovascular disease: damage to the blood vessels supplying the brain can result in a transient ischemic attack or stroke due to decreased supply to areas of the brain.
Microvascular complications
result when there is damage to smaller blood vessels of the body, such as those
supply the eye, kidney or peripheral nerves.
- Diabetic retinopathy: damage to blood vessels supplying the retina of the eye, resulting in reversible blurry vision initially but can lead to reduced vision and potentially blindness.
- Diabetic nephropathy: damage to capillaries supplying the functional units of the kidney, resulting in loss of (normally conserved) protein into urine. As the disease progresses, symptoms of swelling in eyes and legs, weight gain, anorexia and weakness occur. This can eventually progress to chronic kidney disease that will require dialysis.
- Diabetic neuropathy: injury to small blood vessels that supply nerves of the body. Symptoms may include numbness, tingling, altered sensations to a body part, urinary incontinence, erectile dysfunction, gastroparesis, diabetic foot ulcers, and specific symptoms to single affected nerves (eyes, hips, arm).
Treatment and Management
A chronic condition, there is
no cure for diabetes mellitus, and therefore treatment and management focuses
on controlling blood sugar levels, keeping them as close to normal values.
Usually, a combination of diet, exercise and medications are used. The goals of
treatment are to maintain a HbA1C level of 6.5%, but varies for each
individual. In addition, preventative measures are taken to reduce the chronic
complications of diabetes.
Lifestyle Modification: Patient education, exercise, weight loss, and a
diabetic diet are all ways to effectively reduce glucose levels, but may need
additional pharmacologic interventions.
Medications:
There are several groups of
medications that can help one keep their diabetes under control and lead a
healthy life. Your health care provider will prescribe medication(s) based on
several factors: type of diabetes, severity of disease, age, and use (oral vs.
injected).
Oral Diabetic Medication
People with type 2 diabetes are usually initially prescribed oral medications to lower blood glucose levels
- Sulfonylureas
o
Includes: Glyburide,
Glipizide, Glimepiride, Tolbutamide, Tolazamide, Acetohexamide, Chlorpropamide
o
How it works: Stimulates
the pancreas to make more insulin
- Side Effects: hypoglycemia, weight gain, bloating, GI upset, skin rash
- Metformin
o
How it works: Enhances
body’s sensitivity to insulin
- Side Effects: GI upset (diarrhea, nausea, abdominal pain), metallic taste
- Acarbose
o
How it works: Slows down
the absorption of glucose from food
- Side Effects: GI upset (diarrhea, abdominal cramping, flatulence)
- Thiazolidinediones
o
Includes: Rosiglitazone,
Pioglitazone
o
How it works: Reduces
body’s resistance to insulin
- Side Effects: headache, low blood sugar, muscle aches, nausea, vomiting, stomach pain, swelling in legs and ankles
Injectable Medications
Insulin, a hormone naturally
released by the pancreas, helps keep blood glucose in normal ranges by moving
glucose out of the blood stream and into cells for energy. Exogenous insulin
can be given to control glucose levels in diabetic patients. These medications are used for type 1
diabetics who no longer produce sufficient amounts of insulin, or as a
supplementary medication for type 2 diabetics whose blood glucose levels are no
longer controlled by oral medications alone.
There are different types of
insulin that work over different lengths of time. The dose and type of insulin
is individualized for each person, and may have to be adjusted several times
before a regular schedule is set up. The number and type of injections depends
on diet, timings of meal, and exercise.
Types of Insulin
·
Rapid Acting Insulin
(Lispro, Insulin aspart):
o
Begins to work within
5-20 minutes after injection
o
Effects last for 2-5 hours
·
Short Acting (Humulin R,
Insulin R, Iletin I Regular, Novolin R, Velosulin Human):
o
Begins to work within
30-60 minutes after injection
o
Effects last 5-8 hours
·
Intermediate Acting (NPH,
Lente):
o
Begins to work within 1-4
hours after injection
o
Effects last for 14-24
hours
·
Long Acting (ultralente):
o
Begins working within 3-6
hours after injection
o
Effects last for 18-36
hours.
·
Slow Released (Glargine)
o
Begins to work within
1-1.5 hours after injection
o Effects last for 24 hours
