About diabetes
Types of diabetes
Type 1 diabetes (T1D)
Description
- formerly known as Insulin-Dependent Diabetes Mellitus (IDDM).
- characterized by hyperglycemia due to an absolute deficiency of the insulin hormone produced by the pancreas.
- patients require lifelong insulin injections for survival.
- usually develops in children and adolescents (although can occur later in life).
- may present with severe symptoms such as coma or ketoacidosis.
- patients are usually not obese with this type of diabetes, but obesity is not incompatible with the diagnosis.
- patients are at increased risk of developing microvascular and macrovascular complications.
Etiology
- usually (but not always) caused by autoimmune destruction of the beta cells of the pancreas, with the presence of certain antibodies in blood.
- a complex disease caused by mutations in more than one gene, as well as by environmental factors.
Symptoms
- increased urinary frequency (polyuria), thirst (polydipsia), hunger (polyphagia), and unexplained weight loss.
- numbness in extremities, pain in feet (disesthesias), fatigue, and blurred vision.
- recurrent or severe infections.
- loss of consciousness or severe nausea/vomiting (ketoacidosis) or coma. Ketoacidosis more common in T1D than in T2D.
Diagnosis
- diagnosis is made by the presence of classic symptoms of hyperglycemia and an abnormal blood test.
- a plasma glucose concentration >=7 mmol/L (or 126 mg/dL) or >=11.1mmol/L ( or 200mg/dL) 2 hours after a 75g glucose drink.
- in a patient without classic symptoms, diagnosis can also be made by two abnormal blood tests on separate days.
- in most settings (although not always available in resource-poor countries), another test called HbA1C is done to approximate metabolic control over previous 2-3 months and to guide treatment decisions.
Treatment
- overall aim of treatment is symptom relief and prevention or delay of complications by targeting normal blood glucose levels
- lifelong insulin injections in different combinations: short-acting/long-acting, intensive management with multiple injections prior to meals, once or twice daily injections, insulin pump
- consistent supply of insulin essential (however, insulin is unavailable and unaffordable in many poor countries)
- glucometers to self-monitor blood glucose
- early detection and treatment of complications (at intervals recommended by national and international guidelines): eye exam, urine test, foot care, and specialist referral as needed
- patient education about self-monitoring for sign/symptoms of hypoglycemia (such as hunger, palpitations, shakiness, sweating, drowsiness and dizziness) and hyperglycemia
- patient education about diet, exercise, and foot care
- where possible, patient-led support groups and community involvement
Type 2 diabetes （T2D）
Description
- formerly named non-insulin-dependent diabetes mellitus (NIDDM).
- characterized by hyperglycemia due to a defect in insulin secretion usually with a contribution from insulin resistance.
- patients usually do not require lifelong insulin but can control blood glucose with diet and exercise alone, or in combination with oral medications, or with the addition of insulin.
- usually (but not always) develops in adulthood (and is on the rise in children and adolescents).
- is related to obesity, decreased physical activity and unhealthy diets.
- as in T1D, patients are at a higher risk of microvascular and macrovascular complications.
Etiology
- associated with obesity, decreased physical activity and unhealthy diets (and involves insulin resistance in nearly all cases).
- occurs more frequently in individuals with hypertension, dyslipidemia (abnormal cholesterol profile), and central obesity, and is a component of "metabolic syndrome".
- often runs in families but is a complex disease caused by mutations in more than one gene, as well as by environmental factors.
Symptoms
- patients may have no symptoms at all or minimal symptoms for years before being diagnosed.
- may have increased urinary frequency (polyuria), thirst (polydipsia), hunger (polyphagia), and unexplained weight loss.
- may also experience numbness in extremities, pain in feet (disesthesias), and blurred vision.
- may have recurrent or severe infections.
- patients may present with loss of consciousness or coma but this is less common than in T1D.
Diagnosis
- diagnosis is made by the presence of classic symptoms of hyperglycemia and an abnormal blood test.
- a plasma glucose concentration >=7 mmol/L (or 126 mg/dL) or >=11.1mmol/L ( or 200mg/dL) 2 hours after a 75g glucose drink.
- in a patient without classic symptoms, diagnosis can also be made by two abnormal blood tests on separate days.
- in most settings (although it may not be available in some resource-poor settings), another test called HbA1C is done to approximate metabolic control over previous 2-3 months and to guide treatment decisions. This test can also be used to diagnose type 2 diabetes.
- some asymptomatic patients are diagnosed through "opportunistic screening" of high risk groups (at a routine medical visit, the health care provider may identify the patient as being at higher risk of diabetes and recommend a screening test).
- for example, age >45 years of age, a BMI >25 kg/m2 may, being of certain ethnic group or being hypertensive may prompt a screening test.
- in some cases, the patient him/herself requests screening.
Treatment
- overall aim of treatment is symptom relief and prevention or delay of complications by targeting normal blood glucose levels.
- patients treated with diet/exercise, or with addition of one or more categories of oral medications, with a combination of oral medications and insulin, or with insulin alone.
- glucometers to self-monitor blood glucose (with less frequency than with T1D).
- early detection and treatment of complications (at intervals recommended by national and international guidelines): eye exam, urine test, foot care, and specialist referral as needed.
- self-monitoring for signs/symptoms of hypoglycemia (such as hunger, palpitations, shakiness, sweating, drowsiness and dizziness) and hyperglycemia.
- patient education about diet, exercise, and foot care.
Gestational diabetes (GDM)
Description
- characterized by hyperglycemia of varying severity diagnosed during pregnancy (without previously known diabetes) and usually (but not always) resolving within 6 weeks of delivery.
- risks to the pregnancy itself include congenital malformations, increased birth weight and an elevated risk of perinatal mortality.
- increased risk to woman of developing diabetes (T2D) later in life.
Etiology
- the mechanism is not completely well understood but hormones of pregnancy appear to interfere with insulin action.
Symptoms
- increased thirst (polydipsia) and increased urination (polyuria) are more commonly noted (although other symptoms can be present).
- because pregnancy itself causes increased urination, these symptoms are difficult to recognize as abnormal.
- a larger than normal baby during pregnancy (noted on routine prenatal exam) may prompt diabetic screening.
Diagnosis
- standard OGTT is done at 24-28 weeks after an overnight fast (fasting plasma glucose and a plasma glucose 2 hours after 75g glucose drink is done).
- a 2 hour level >=7.8 mmol/L (or 140 mg/dL) is diagnostic of gestational diabetes.
- If fasting and postprandial blood sugars are elevated in the first trimester, this may indicate preexisting diabetes mellitus (which is considered a different condition, with different implications).
Treatment
- strict metabolic control of blood glucose to lower obstetrical risks..
- patients treated with diet/exercise, with addition of oral medications, or with the addition of insulin.
- glucometers to self-monitor blood glucose.
- patient education about diet and exercise.
- patient education after delivery regarding weight loss/exercise to prevent future diabetes.
- lifelong screening for T2D as patient will be in high risk category.