Related Subjects: Type 1 DM
|Introduction to Type 2 Diabetes
|Management of Type 2 Diabetes
|Diabetes in Pregnancy
|HbA1c
|Diabetic Ketoacidosis (DKA) Adults
|Hyperglycaemic Hyperosmolar State (HHS)
|Diabetic Nephropathy
|Diabetic Retinopathy
|Diabetic Neuropathy
|Diabetic Amyotrophy
|Maturity Onset Diabetes of the Young (MODY)
|Diabetes: Complications
Insulin resistance means that higher doses of insulin are required for the same physiological activity.
Basic Blood Glucose Ranges (UK and US Units)
Range Category |
UK Units (mmol/L) |
US Units (mg/dL) |
Normal (Fasting) |
4.0 - 5.9 |
72 - 106 |
Normal (After Meal) |
4.0 - 7.8 |
72 - 140 |
Pre-Diabetes (Fasting) |
6.0 - 6.9 |
108 - 124 |
Diabetes (Fasting) |
≥ 7.0 |
≥ 126 |
Hypoglycaemia (Low Blood Sugar) |
< 4.0 |
< 72 |
Hyperglycaemia for Random Diabetes Diagnosis |
11.1 |
200 |
High Hyperglycaemia |
20 |
360 |
Severe Hyperglycaemia |
30 |
540 |
International Definitions
- Normal Fasting sugar < 6.1 mmol/L (110 mg/dL) and 2 hr < 7.8 mmol/L (140 mg/dL)
- Diabetes: Fasting Blood sugar >7.0 mmol/L (126 mg/dL)
- Impaired Glucose tolerance OGTT 2 hr Glucose >7.8-11 mmol/L (140-199 mg/dL)
- Diabetes: Random >11.1 mmol/L (200 mg/dL) + symptoms (confirm with repeat test on another day if asymptomatic)
About Diabetes
- A chronic condition characterized by hyperglycaemia due to insulin deficiency or resistance.
- Increases long-term vascular risks.
- Some patients may require insulin therapy, though not all develop ketosis except in rare cases.
Aetiology
- Polygenic factors contribute strongly, with 90% concordance in identical twins.
- Homeostasis typically maintains blood glucose levels between 3.5-8.0 mmol/L.
- There is a partial loss of beta-cell function in the islets of Langerhans, alongside increased insulin resistance.
- Islet cell amyloid seen at postmortem rather than beta-cell destruction.
Criteria for Diagnosis
- Symptomatic patients with a fasting plasma glucose ≥ 7.0 mmol/L.
- Fasting plasma glucose ≥ 7.0 mmol/L on separate days if asymptomatic.
- Random plasma glucose ≥ 11.1 mmol/L with confirmatory testing if asymptomatic.
Physiology of Glucose Management
- The liver plays a key role in regulating blood glucose levels by converting glucose to glycogen and releasing it when necessary.
- Insulin allows glucose to enter fat cells and muscle, promoting storage and energy usage.
Secondary Causes of Diabetes
- Endocrine disorders (e.g., acromegaly, Cushing's syndrome).
- Pancreatic destruction (e.g., chronic pancreatitis, cystic fibrosis, haemochromatosis).
- Genetic insulin resistance (e.g., defects in insulin receptor or action).
Clinical Presentation
- Polyuria, polydipsia, and potential weight loss.
- Complications can include eye problems, cardiovascular issues, foot ulcers, and infections (e.g., Candida balanitis).
Investigations
- Blood glucose levels, lipid profile, HbA1C for long-term glucose control.
- FBC, U&E, creatinine clearance, urinalysis for proteinuria.
Management
- Lifestyle: weight loss, dietary advice, smoking cessation, exercise.
- Blood Pressure Control: Aim for < 135 mmHg (ACE inhibitors preferred).
- Glycaemic Control: Use HbA1C as a marker, adjusting therapy as needed (wait 2 months before rechecking post-therapy change).
- Additional medications: Aspirin (75 mg), statins (e.g., Simvastatin).
Improving Glycaemic Control: Oral Agents
- Lifestyle changes (diet, exercise).
- Monotherapy with metformin; add other agents if HbA1C > 58 mmol/mol.
- Combinations: Metformin with DPP4 inhibitors, sulfonylureas, or SGLT-2 inhibitors as needed.
- Transition to insulin therapy if control remains inadequate.
Hypoglycaemia can occur with insulin, sulfonylureas, and glitazones.
Notes on Oral Agents
- Metformin: Increases insulin sensitivity, beneficial in obesity.
- Sulfonylureas: Stimulate insulin release; may cause weight gain.
- Glitazones: Enhance insulin sensitivity, but avoid in heart failure.
- SGLT-2 Inhibitors: Promote glucose excretion via kidneys, aiding weight loss.
Management in the Elderly
- Focus on quality of life and minimize hypoglycaemia risk.
- Less stringent HbA1c targets (e.g., 58-64 mmol/mol) for frail or elderly patients with limited life expectancy.
Guidelines and Algorithms
References