Health and Diseases_Non-communicable diseases_Diabetes P.1
Diabetes mellitus
Definition: Ametabolic disorder characterized byhyperglycemia(high blood sugar)resulting fromabsolute or relativedeficiencyininsulinsecretion and/or insulinaction.
/ "Diabetes" is a Greek word meaning a “siphon". "Mellitus" comes from the Greek word "sweet".The ancient Chinese tested for diabetes by observing whether ants were attracted to a person's urine; medieval European doctors tested for it by tasting the urine themselves.
Hyperglycemia itself can lead todehydration andketoacidosis, coma and even death. Longer-term complications includecardiovascular disease, chronic renal failure, retinal damage with eventualblindness, nerve damageand eventual tissue death (gangrene) with risk of amputation of toes, feet, and even legs.
The Two most important forms of diabetes are due to
decreased production of insulin (diabetes mellitus type 1, IDDM, or
decreasedsensitivity of body tissues to insulin (diabetes mellitustype 2,NIDDM, the more common form > 90%).
The former requires insulininjections, while the latter is generally managed with oralmedication (of blood sugar lowering drugs) and only requires insulin if the tablets are ineffective.
Statistics
In 2004, according to the WHO, more than 150 million people worldwide suffer from diabetes. Its incidence is increasing rapidly. Diabetes mellitus occurs throughout the world, but is more common (especially type 2) in the more developedcountries. The greatest increase in prevalence rate is, however, expected to occur in AsiaandAfrica, where most of the diabetic patients will be seen by 2025.
- Diabetes is more common in developed countries or developing countries? Why?
- Why do you think the greatest increase is expected to happen in Asia and Africa?
Causes and types
The role of insulin
Most of the carbohydrates in food are rapidly digested toglucose, the principal sugar in blood. Insulin is produced by beta cells in the pancreas in response to rising levels of glucose in the blood, as occurs after a meal.
Insulin is the principalhormone that regulates uptake of glucose into cells (primarily muscle and fat cells) from the blood, Insulin makes it possible for most body tissues to take glucose from the blood for use as fuel or for storage.
Insulinis also the principal control signal for conversion of glucose to glycogenfor storagein liver and muscle cells.
Insulin is the principal signal in promoting many anabolic processes such as cell growth, cellular protein synthesis, and fat storage.
A)Type 1 diabetes mellitus
Type 1 diabetes is most commonly diagnosed in children and adolescent. It is an autoimmunedisorder in which the body's ownimmune systemattacks the beta cells in the Islets of Langerhans of the pancreas, leading to reduced insulin production. The autoimmune attack may be triggered by environmental factorsandviruses.
Q. Type 1 diabetes is due to insufficient insulin secretion. Besides autoimmune attack, suggest other possible cause for type I diabetes.
B)Type 2 diabetes mellitus
Type 2 diabetes is characterized by "insulin resistance" as body cells do not respond appropriately when insulin is present. This is a more complex problem than type 1, but is sometimes easier to treat, since insulin is still produced, especially in the initial years. Type 2 may go unnoticed for years in a patient before diagnosis, since the symptoms are typically milder (no ketoacidosis) and can be sporadic. However, severecomplications can result from unnoticed type 2 diabetes, including renal failure, and coronary artery disease.
The majority of patients with type 2 diabetes mellitus areobese - chronic obesity leads to increased insulin resistance that can develop into diabetes, most likely because adipose tissue is a source of chemical signalsthatinhibit glucose transport across cell membrane.
Genetics
Both type 1 and type 2 diabetes are at least partlyinherited. Type 1 diabetes appears to be triggered by infection, stress, or environmentalfactors (e.g. exposure to a causative agent). There is an evenstrongerinheritance pattern for Type 2 diabetes. It is also often connectedtoobesity. Age is also thought to be a contributing factor, as most type 2 patients in the past were older.
Signs and symptoms
Early symptoms of type 1 diabetes are:
frequent urination
and increased thirst, and consequent increased fluid intake.
increased appetite
weight loss(despite normal or increased eating),
Type 2 diabetes almost always has a slow onset (often years), but in type 1, particularly in children, onset may be quite fast (weeks or months).
Q.Hyperglycemia leads to thirst and cell dehydration, why?
Q.Suggest why diabetics experience excessive hunger and weight loss despite constant eating?
Especially dangeroussymptoms in diabetics include the smell of acetone / fruity smell on the patient's breath (a sign ofketoacidosis), a rapid, deep breathing, and any altered state of consciousness or arousal. The most dangerous form of altered consciousness is the so-called "diabetic coma" which produces unconsciousness and death if untreated.
Q.Ketoacidosis is a condition in which ketones and fattyacids build up in the body. ketones and fatty acids are strong organic acids that can lower the blood pH to a harmful level of acidity. Suggest how lack of insulin leads to Ketoacidosis.
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Q.Explain how ketoacidosis lead to deep and rapid breathing?
Q.One of the symptoms of ketoacidosis is a fruity breath odor, why?
- Ketoacidosis comes with severe loss of potassium, sodium ions and body fluid in urine. Why? (Hint: Ketones are negatively charged)
Hypoglycemia
Hypoglycemia in diabetic patients almost always arises as a result of poor management of the disease
- Suggest some improper practices in diabetic patients that can lead to hypoglycemia.
Ifbloodglucose levels are toolow, consciousness can be altered, in extreme cases, leading to coma and or even death and braindamage. Experienced diabetics can often recognise the symptoms early on - all diabetics should always carry something sugary to eat or drink as these symptoms can be rapidly reduced if treated early enough. In the case of children, this can be a type of candy disliked by the patient, to prevent concerns about unnecessary use.
Q.One way of treating hypoglycemia is an injection of a hormone which causes the liver to convert its stores of glycogen to be released as glucose into the blood. Suggest the name of such a hormone.
Blood Testing
Diabetesscreening is recommended for many with several different riskfactors. The screening test may be a random glucose, or a formalglucose tolerance test.
Screening recommended for adults who has the following Risk factors:
age 40 or 50 years,
obesity,
family history of diabetes,
high blood pressure, elevated cholesterol levels, coronary artery disease, past gestational diabetes, chronic pancreatitis, etc
Blood glucose level is measured in either mg/dL (milligrams per deciliter in the USA) or mmol/L (millimoles per litre in Europe) of blood. The average normal person should have a glucose level of around 4.5 to 7.0 mmol/L In the diabetic patient, more specifically type 2 patients, it is important to maintain good glucose control, usually 1-2 hours after a meal aiming for a level of <10.0 mmol/L.
Diabetes mellitus is characterized by recurrent or persistenthyperglycemia, and is diagnosed by demonstrating any one of the following:
two fasting plasma glucose levelsabove 7 mmol/l (125 mg/dl) on different days;
plasma glucose above 11 mmol/l (200 mg/dl) two hours after a 75 g glucose load; or
symptoms of diabetes and a random glucose above 11 mmol/l (200 mg/dl).
A level of <3.8 mmol/L is usually described as a hypoglycaemic attack. Most diabetics 'know' when they're going to go hypo and usually are able to eat some food or drink something sweet to raise levels. It is important to remember though, that a patient who is hyperglycaemic (high glucose) can also have a hypo under certain conditions i.e. not eating regularly, or strenuous exercise, followed by fatigue.
Levels greater than 13-15 mmol/L should be monitored closely and the patient is advised to seek urgent medical attention as soon as possible if this continues to rise after 2-3 tests.
Hyperglycaemia is not as easy to detect as hypoglycaemia and usually happens over a period of days rather than hours or minutes. If left untreated this can result in diabeticcoma and death.
Prolonged and elevated levels of glucose in the blood, which is left unchecked and untreated will, over time, result in serious diabetic complications and sometimes even death.
Long-term complications
Among the major risks of the disorder are chronic problems affecting multipleorgansystems which will eventually arise in patients with poorglycemiccontrol. Many of these arise from damage to the bloodvessels.
Retinal damagewhich can lead toblindness;
Damage to peripheral nerve and blood vessel can lead to foot ulcers, and possibly progressing totissue death and infection, sometimes requiring limb amputation.
Damage to nephrons which can lead to renal failure.
Heart disease
stroke
Q.What healthy advice would you give to someone diagnosed with diabetes mellitus to avoid these complications?
Treatment
Diabetes is achronic disease with no cureas of 2004, but it can almost always be managed effectively. Management of this disease may include lifestylemodifications such as losing weight, diet and exercise to long-term use of oral hypoglycemics or insulin therapy.
Nowadays, the goal for diabetics is to avoid or minimize chronic diabetic complications, as well as to avoidacute problems of hyperglycemia or hypoglycemia.
Currently, type 1 diabetics is treated with insulininjections, lifestyleadjustments, and careful monitoring of blood glucose levels using blood test kits. The treatment must be continued indefinitely. Experimental replacement of betacells (by transplant) is being investigated in several research programs and may become clinically available in future.
For type2diabetics, diabetic management consists of a combination ofdiet, exercise, and weight loss, in any achievable combination depending on the patient. Patients who have poor diabetic control after lifestyle modifications are typically placed on oral hypoglycemics. Some Type 2 diabetics eventually fail to respond to these and must proceed to insulin therapy.
Patient education and compliance with treatment is very important in managing the disease. Improper use of medications and insulin can be very dangerous causing hypo- or hyper-glycemic episodes.
Q.What do you think is 1) the decrease food intake 2) exercise has on the amount of insulin injection required?
Q.What is the consequence of excess insulin injection has on the body?
- The production of abnormal amounts of urine is a symptom shared by several diseases (most commonly of the kidneys), one such disease is diabetes insipidus, which is characterized by excretion of large amounts of severely diluted urine. It denotes inability of the kidney to concentrate urine. Suggest one possible cause of diabetes insipidus.
Q.Formerly, type 1 diabetes was called "childhood" or "juvenile" diabetes or "insulin dependent" diabetes. Explain why each is a misnomer.
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