Makindo Medical Notes

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)

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

• NICE guidance on T2DM