Diabetes Mellitus (General Management)

Clinical assessment

Suspect based on symptoms (classic polyuria/polydipsia/polyphagia/weight loss, or non-specific fatigue/infections/blurred vision). Screening recommended for high-risk individuals. Differentiate Type 1 (usually younger onset, absolute insulin deficiency, prone to DKA) from Type 2 (usually older onset, insulin resistance +/- deficiency, often overweight/obese).

Investigations

• Blood Glucose Testing:
• - Fasting Plasma Glucose (FPG): ≥7.0 mmol/L (126 mg/dL) on ≥2 occasions.
• - 2-hour Post-load Glucose (2h-PG) during 75g Oral Glucose Tolerance Test (OGTT): ≥11.1 mmol/L (200 mg/dL).
• - Random Plasma Glucose (RPG): ≥11.1 mmol/L (200 mg/dL) WITH classic symptoms of hyperglycaemia.
• Glycated Haemoglobin (HbA1c): ≥6.5% (48 mmol/mol) on ≥2 occasions (reflects average glucose over ~3 months). Note: Less reliable in conditions affecting RBC turnover (anaemia, haemoglobinopathies, CKD).
• Urine Ketones: Check if DKA suspected (esp. Type 1, high glucose, ill).
• Baseline tests for complications/co-morbidities: Lipids, Renal function (U&Es, Creatinine, eGFR), Urinalysis (protein/microalbuminuria), ECG, Fundoscopy.
• Autoantibodies (GAD65, IA-2, Insulin): Can help confirm Type 1 diagnosis (specialist).

Diagnostic criteria

Diagnosis based on meeting WHO/ADA glucose or HbA1c thresholds on repeat testing (unless unequivocal hyperglycaemia with symptoms).

Non-pharmacological management

• Lifestyle Modification (Foundation for all types, esp. Type 2):
• - Diabetes Education: Self-management skills (glucose monitoring, diet, exercise, medication use, sick day rules, foot care).
• - Medical Nutrition Therapy (MNT): Healthy eating pattern - emphasize fruits, vegetables, whole grains, lean protein, healthy fats. Portion control. Reduce intake of sugary drinks, refined carbohydrates, saturated/trans fats. Consistent carbohydrate intake helpful for insulin users. (See UCG 19.1.3 for detailed advice).
• - Physical Activity: ≥150 minutes/week of moderate-intensity aerobic exercise (e.g., brisk walking) spread over ≥3 days/week, plus resistance training 2-3 times/week.
• - Weight Management: Aim for modest weight loss (5-10%) if overweight/obese (Type 2).
• - Smoking Cessation.
• - Moderate Alcohol Consumption.
• - Psychosocial Support.
• Blood Glucose Monitoring: Self-monitoring of blood glucose (SMBG) using glucometer, especially for insulin users or those with risk of hypoglycemia. Frequency depends on therapy/stability.
• Foot Care: Daily inspection, proper footwear, podiatry referral if needed.

Pharmacological treatment

• Goal: Achieve individualized glycaemic targets (e.g., HbA1c <7% for most non-pregnant adults, fasting glucose <7 mmol/L, postprandial <10 mmol/L) while minimizing hypoglycemia and side effects. Targets may be less strict for elderly/frail patients.
• Type 1 Diabetes: Requires Insulin Therapy from diagnosis.
• - Multiple Daily Injections (MDI - Basal-Bolus Regimen): Long/intermediate-acting basal insulin (e.g., NPH/Insulatard, Glargine, Detemir) once/twice daily PLUS Rapid/short-acting bolus insulin (e.g., Aspart, Lispro, Regular/Actrapid) before meals. Dose adjusted based on glucose monitoring, carb intake, activity.
• - Premixed Insulin (e.g., Mixtard 30/70, Biphasic Aspart): Twice daily before breakfast/supper. Less flexible than basal-bolus.
• - Initial total daily dose typically 0.5-1.0 units/kg/day.
• - Continuous Subcutaneous Insulin Infusion (CSII - Insulin Pump): Specialist management.
• Type 2 Diabetes: Stepwise approach.
• - Step 1: Lifestyle modification + Metformin (unless contraindicated). Start 500mg OD/BID with meals, increase gradually to target 1.5-2g/day (divided doses) as tolerated/needed. Contraindicated if severe renal impairment (eGFR <30), severe liver disease, acute illness/hypoxia.
• - Step 2 (Add second agent if HbA1c target not met after ~3 months): Choice depends on patient factors (co-morbidities, weight, hypoglycemia risk, cost, availability).
• - Sulfonylurea (SU): e.g., Glibenclamide, Glimepiride (UCG mentions Glimepiride 1-4mg OD). Stimulates insulin secretion. Risk of hypoglycemia, weight gain.
• - DPP-4 Inhibitors (e.g., Sitagliptin, Vildagliptin): Glucose-dependent insulin release, low hypoglycemia risk.
• - SGLT2 Inhibitors (e.g., Empagliflozin, Dapagliflozin): Increase urinary glucose excretion. Benefits for CVD/HF/CKD. Risk of GU infections, DKA (rare).
• - GLP-1 Receptor Agonists (e.g., Liraglutide, Semaglutide - Injectable): Promote insulin secretion, suppress glucagon, slow gastric emptying, promote weight loss. GI side effects common.
• - Thiazolidinediones (TZDs - e.g., Pioglitazone): Improve insulin sensitivity. Risk of fluid retention/HF, fractures.
• - Step 3 (Add third agent or Insulin if target still not met):
• - Basal Insulin: Often initiated as third agent. Start NPH (Insulatard) or long-acting analogue (Glargine) 10 units (or 0.1-0.2 units/kg) at bedtime, titrate based on fasting glucose.
• - Intensification: May require adding pre-meal rapid/short-acting insulin or switching to premixed insulin BID (Stop SU when starting multiple insulin injections).
• Management of Cardiovascular Risk Factors:
• - Statins (Atorvastatin 20-40mg or Simvastatin 20-40mg): Recommended for most adults >40yrs with diabetes, or younger with risk factors/CVD.
• - Antihypertensives (Target <130/80): ACEi/ARBs first-line (see REN002/CV006).
• - Aspirin (75-100mg daily): For secondary prevention (post-MI/Stroke). Primary prevention controversial, consider if high CVD risk.

Monitoring

• Glycaemic Control: HbA1c every 3-6 months. SMBG as needed.
• Blood Pressure: Every visit.
• Lipids: Annually (or more often if treating).
• Complication Screening:
• - Eyes (Retinopathy): Dilated fundus exam annually.
• - Kidneys (Nephropathy): Urine ACR/PCR and serum Creatinine/eGFR annually.
• - Feet (Neuropathy/PAD): Comprehensive foot exam annually (inspection, sensation testing, pulses).
• - Cardiovascular Risk Assessment.