Endocrinology Flashcards
What is Type 1 Diabetes?
Autoimmune destruction of pancreatic beta cells leading to complete insulin deficiency.
Risk Factors of T1DM?
- > Family history of HLA DR3-DQ2 or HLA DR4-DQ8
- > Northern European
- > Autoimmune diseases – 90%
Pathophysiology of T1DM?
Autoantibodies attack beta cells in the Islets of Langerhans -> Insulin deficiency -> Hyperglycemia.
Continuous breakdown of glycogen from liver (gluconeogenesis) -> Glycosuria
Signs and Symptoms of T1DM?
Classic Triad: Polydipsia, Polyuria, Weight- loss [BMI < 25]
Usually a short history of severe symptoms
May also present with ketosis
Diagnosis of T1DM?
-> Random Plasma Glucose > 11mmol/L
Treatment of T1DM?
> Insulin
Short - acting insulins and insulin analogues (4-6 hrs)
Longer - acting insulin (12-24 hrs)
**Typical patient presenting with NEW Type 1 DM:
Polydipsia, Polyuria, Ketosis, Rapid weight- loss, Young, BMI <25, personal/ family history of autoimmune disease. **
What is Type 2 Diabetes?
=> Non – insulin dependent
Patients gradually become insulin resistant/ pancreatic beta cells fail to secrete enough insulin or BOTH.
Progresses from impaired glucose tolerance.
Causes of T2DM?
- Reduced insulin secretion, +/- increased insulin resistance.
- Others: Gestational Diabetes, Steroids, Cushing’s, Chronic pancreatitis.
Risk factors of T2DM?
- > Lifestyle factors: Obesity, Lack of exercise, Calorie and Alcohol excess
- > Higher prevalence in Asian men
- > Above 40 yrs age – later onset
- > Hypertension
Signs and Symptoms of T2DM?
Polydipsia Polyuria Glycosuria Central obesity Slower onset Blurred vision
Investigations of T2DM?
- > Fasting plasma glucose: more than 7 mmol/L
- > Random Plasma Glucose: more than 11 mmol/L
- > HbA1c more than 48 mmol/L
Treatment of T2DM?
1st Line = Lifestyle Changes
> Dietary advice: High in complex carbs. Low in fat
> Smoking cessation
> Decrease alcohol intake
> Exercise
> Regular blood glucose and HbA1c monitoring
2nd Line = Medications
> Metformin (biguanide): Increases insulin sensitivity – first choice in overweight patients
> If HbA1c remains high then DUAL Therapy with Metformin:
+ DPP4 inhibitor
+ Sulphonylurea (gliclazide) - Increases insulin secretion
+ Pioglitazone
> If still high = TRIPLE Therapy
> Then Insulin
What is Diabetic Ketoacidosis?
=> Complete lack of insulin results in high ketone production.
Aetiology of DKA
Untreated or undiagnosed T1DM
Infection/illness
Pathophysiology of DKA
Absence of insulin -> uncontrolled catabolism -> unrestrained gluconeogenesis and decreased peripheral glucose uptake -> Hyperglycaemia.
Hyperglycaemia -> Osmotic diuresis -> Dehydration
Peripheral lipolysis for energy -> Increase in circulating free fatty acids -> oxidised to Acetyl CoA -> Ketone bodies(acidic) = ACIDOSIS
Symptoms of DKA
Extreme diabetes symptoms plus: • Nausea + Vomiting • Weight Loss • Confusion and reduced mental state • Lethargy • Abdominal pain
Signs of DKA
- Kussmaul’s breathing [rapid slow]
- ‘Pear drop’ breath [due to ketones]
- Hypotension
- Tachycardia
Investigation of DKA
- > Random Plasma Glucose > 11mmol/L
- > Plasma ketone > 3mmol/L
- > Blood pH < 7.35 or Bicarb < 15mmol/L
- > Urine dipstick: Glycosuria, Ketonuria
- > Serum U+E: -Raised urea + creatinine. -Decreased Total K+, Increased serum K+.
Treatment of DKA
- ABC management
- Replace fluid – 0.9% saline IV
- IV insulin
- Restore electrolytes – e.g. K+
What is Hyperosmolar Hyperglycaemic State (HHS):
=> Marked hyperglycaemia, Hyperosmolality, Mild/ no ketosis
Medical Emergency – Serious complication of T2DM.
Aetiology of HHS
- Untreated or undiagnosed T2DM
- Infection/illness
