Diabetes Overview Quiz

Disorders of the Posterior Pituitary: Diabetes Insipidus

• Diabetes insipidus is caused by insufficient anti-diuretic hormone (ADH).
• ADH increases water reabsorption from the kidney's filtrate, reducing urine volume.
• Inadequate ADH results in large volumes of dilute urine.
• Treatment aims to replace the missing ADH, often with Desmopressin.

Diabetes Mellitus

• Diabetes mellitus is a group of disorders characterized by high blood glucose levels.
• Two main types exist: type 1 (insulin-dependent) and type 2 (non-insulin-dependent).
• Similar symptoms across types include: high blood glucose (hyperglycemia), glucose in urine (glycosuria), ketones in urine (ketonuria), frequent urination (polyuria), excessive thirst (polydipsia), increased appetite (often in type 1), weight loss (often in type 1), fatigue, and abdominal pain.

Types of Diabetes Mellitus

• The WHO (2019) outlines five types of diabetes mellitus: type 1, type 2, gestational diabetes, other specific types, and hybrid forms.
• Gestational diabetes is characterized by hyperglycemia first detected during pregnancy.

Type 1 Diabetes

• Type 1 diabetes commonly emerges in childhood or early adulthood.
• Globally, type 1 diabetes mellitus (T1DM) accounts for 5% to 10% of diabetes cases.
• It's primarily caused by an autoimmune destruction of beta cells in the pancreas.
• This leads to a significant reduction, or complete loss, of insulin production.
• Girls and boys are equally likely to develop type 1; white populations have a higher incidence compared to non-white populations.

Genetic Factors in Diabetes

• Genetic predisposition plays a role in type 1 diabetes, but there's no single 'diabetes' gene. Multiple genes are involved.
• Identical twins exhibit a 30% to 50% risk of type 1 if one twin has it.
• The risk of a child developing type 1 if the mother has it is less than 4%.

Pathophysiology of Type 1 Diabetes

• The beta cells in the islets of Langerhans in the pancreas produce insulin.
• Insulin acts like a key, allowing glucose to enter cells and providing energy.
• In T1DM, the beta cells are destroyed by the body's immune system.
• This destruction leads to an absolute deficiency of insulin.
• In most cases (~90%), type 1 diabetes is an autoimmune disorder.
• Autoreactive T-cells attack beta cells; viral infection sometimes triggers this autoimmune response.
• Islet cell antibodies, glutamic acid decarboxylase antibodies, insulin autoantibodies, and IA-2A are examples of these antibodies.

Signs and Symptoms of Type 1 Diabetes

• Weight loss.
• Fatigue.
• Excessive thirst.
• Frequent urination (polyuria).
• In children, failure to thrive.
• Possible urinary tract infections due to high glucose levels.
• High levels of ketoacidosis.

Prognosis and Management of Type 1 Diabetes

• Complete destruction of pancreatic islets often requires lifelong insulin treatment.
• Expected lifespan reduces by 13 years on average, though manageable blood glucose levels can improve long-term outcomes.
• Good blood glucose control delays and potentially reduces the severity of diabetes complications.
• Care must be taken to ensure insulin dosage matches food intake.
• Uncontrolled insulin can lead to coma or death.
• Conscious patients receive sugary snacks or carbohydrates, while unconscious patients require immediate medical assistance and intramuscular glucagon injection, plus potentially intravenous glucose.

Type 2 Diabetes Mellitus (T2DM)

• T2DM accounts for up to 95% of all diabetes cases.
• Characterized by insulin resistance in tissues and reduced insulin production by beta cells.
• High blood glucose levels result from insulin resistance and reduced production.
• This damage to beta cells worsens the condition.

Risk Factors of Type 2 Diabetes (T2DM)

• Increasing age (often >40 years).
• Obesity.
• Family history.
• Sedentary lifestyle.
• Diet high in processed foods, red meat, fat, and carbohydrates.
• Body fat distribution (abdominal fat is a greater risk).
• Smoking.

Pathophysiology of Type 2 Diabetes (T2DM)

• Pancreatic beta cells struggle to keep up with demand, leading to gradual failure.
• Resulting insulin deficiency is often compounded by insulin resistance (reduced cellular response to insulin).
• Symptoms become apparent as blood glucose levels rise.
• Some beta-cell function remains in some individuals with T2DM

Signs and Symptoms of Type 2 Diabetes (T2DM)

• 60% have no symptoms at diagnosis.
• Excessive thirst (polydipsia).
• Frequent urination (polyuria).
• Excessive hunger (polyphagia).
• Weight loss.
• Fatigue.
• Symptoms of end-organ damage, such as impaired vision (retinopathy), nerve damage, or kidney damage (renal impairment).
• Diabetic retinopathy often appears quickly after diagnosis.

Management and Prognosis of Type 2 Diabetes (T2DM)

• Weight reduction, increased exercise, and decreased food intake can resolve hyperglycemia in some cases.
• Medication (oral hypoglycaemics) is often required after initial lifestyle changes.
• Medications target glucose production, insulin output, or cellular sensitivity to insulin.
• Potential for complications requires close blood glucose monitoring.
• Insulin therapy is used if lifestyle changes and medications do not control blood glucose levels.

Gestational Diabetes

• Pregnancy induces insulin resistance, potentially leading to hyperglycemia and frank diabetes.
• Previously non-diabetic women who develop diabetes during pregnancy are diagnosed with gestational diabetes.
• Affects approximately 14% of pregnancies worldwide.
• Risk factors include maternal overweight/obesity, history of gestational diabetes in previous pregnancies, and family history of diabetes.

Pathophysiology of Gestational Diabetes

• Pregnancy affects both the mother and baby.
• Increases risk factors of pre-eclampsia, premature birth, and T2DM later in life, along with increased risk for poor birth outcomes for the baby.
• High blood glucose levels during pregnancy can affect both mother and baby.
• Mothers may require caesarean section if blood glucose is not controlled as risks to mother and baby can increase.

Other Specific Types of Diabetes

• Pancreatitis, pancreatic cancer or cystic fibrosis damage
• Hormones like thyroxine and cortisol oppose or interfere with insulin's effects.
• Drugs like adrenergic agonists mimic adrenaline's impact on insulin function.
• Infections, such as rubella or mumps, can induce destruction of beta cells.

Complications of Diabetes Mellitus: Microvascular Complications

• Diabetic retinopathy: damage to the retina of the eyes, a major cause of blindness worldwide.
• Diabetic neuropathy: tingling, pricking, aching, and hypersensitivity, leading to potential foot injury and non-responsive pain.

Complications of Diabetes Mellitus: Macrovascular Complications

• Diabetic foot: a significant reason for hospital admissions and potentially gangrenous changes, necrosis, and amputation.

Diabetic Ketoacidosis (DKA)

• DKA mainly occurs in type 1 diabetes.
• Insufficient insulin causes the body to shift from using glucose to burning stored fats; ketone production is a byproduct.
• Accumulation of ketones leads to ketoacidosis.
• Loss of consciousness or death is a potential outcome.
• DKA requires urgent treatment to restore glucose levels and balance fluids and electrolytes.

Other Complications of Diabetes (III, IV, V)

• Elevated risk of cataract formation.
• Increased risk of uterine and pancreatic malignancies.
• Increased susceptibility to various infections.

Hyperthyroidism

• Excessive thyroid hormone (T3 and T4) production, often due to Graves’ disease (autoimmune).
• Antibodies mimic Thyroid Stimulating Hormone (TSH).
• Other causes include thyroid cancer, thyroid nodules, viral thyroiditis, and certain medications.

Signs and Symptoms of Hyperthyroidism

• Cardiovascular issues: hypertension, tachycardia, palpitations, potential atrial fibrillation.
• Increased metabolism leads to heat intolerance.
• Goiter: thyroid gland swelling.
• Nervousness, restlessness, fatigue, insomnia, shortness of breath, weight loss despite increased appetite.
• Frequent stools, diarrhea, nausea, vomiting, muscle weakness, tremors, warm/flushed skin, and fine hair.
• Staring gaze, and exophthalmia.
• Thyroid function tests (T3 and T4 elevated, TSH suppressed).

Complications of Hyperthyroidism (in pregnancy and long term)

• In pregnancy: increased risk of miscarriage, premature labour, eclampsia, and low birth weight.
• Long term: associated with cardiovascular disease and osteoporosis.

Management of Hyperthyroidism

• Surgery (thyroidectomy) to remove part or all of the thyroid gland.
• Radioactive iodine to destroy thyroid tissue, which can lead to hypothyroidism necessitating thyroid hormone replacement therapy.
• Antithyroid drugs (inhibitors) to decrease hormone production from the gland.
• Beta-blockers used to modulate symptoms (tachycardia, palpitations, tremors.)

Hashimoto Thyroiditis

• Autoimmune disorder causing hypothyroidism.
• More prevalent among women, frequently presented in middle age.
• Strong familial tendency.
• Signs and symptoms: low T3 and T4 levels, high TSH levels.
• Management/prognosis typically involves lifelong thyroxine replacement therapy.

Hypothyroidism

• Worldwide: often due to iodine deficiency.
• In regions with adequate iodine: frequently Hashimoto's disease.
• Other causes include: thyroid development failure, hyperthyroidism treatments, other medications, radiation therapy, thyroid infections.

Signs and Symptoms of Hypothyroidism

• Confusion, lethargy, forgetfulness, depression, bradycardia, weight gain, constipation, muscle cramps, myalgia, brittle nails, dry cool/pale skin, coarse/thinning hair, generalized edema, cold intolerance.
• Thyroid function tests (T3 and T4 reduced, TSH elevated).

Consequences of Hypothyroidism (during pregnancy)

• In pregnancy, hypothyroidism may lead to recurring miscarriages, premature labor, and child with reduced intelligence.
• Management usually includes lifelong thyroxine replacement therapy.

Test your knowledge on the characteristics, symptoms, and management of Type 1 and Type 2 diabetes. This quiz covers key concepts about diabetes mellitus, including associated health risks and classifications. Perfect for students studying endocrinology or general health topics.