Type 1 Diabetes Mellitus, in Adults

Monitoring Following Down Referral

Targets for Control

Medicine Treatment 

Insulin Regimens

Referral

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ICD-10 Code: E10.9

• Type 1 diabetes mellitus is a rare condition and should be diagnosed and monitored at hospital level. Only stable patients may be down referred for chronic medicines

MONITORING FOLLOWING DOWN REFERRAL

At every visit:

• Finger-prick blood glucose
• Weight
• Blood pressure

Annually:

• HbA1c, one month before next hospital appointment

TARGETS FOR CONTROL

Glycaemic targets for control:

Patient type	Target HbA1c	Target FBG*	Target PPG*
- Young, low risk - Newly diagnosed - No CVS disease	<6.5 %	4.0-7.0 mmoL/L	4.4-7.8 mmol/L
- Majority of patients	<7.0%	4.0-7.0 mmol/L	5.0-10.0 mmol/L
- Elderly - High risk - Hypoglycaemic unawareness - Poor short-term prognosis	<7.5%	4.0-7.0 mmol/L	<12.0 mmol/L

*FBG: fasting blood glucose: PPG: post-prandial blood glucose                        

Non-glycemic targets:

• Body mass index <25 kg/m2
• BP <140/90 mmHg

The increased risk of hypoglycaemia must always be weighed against the potential benefit of reducing microvascular and macrovascular complications

MEDICINE TREATMENT

• As type 1 diabetes mellitus usually presents with diabetic ketoacidosis, treatment is usually initiated with insulin and the patient is stabilised at hospital level. Oral anti-diabetic medicines should not be used to treat type 1 diabetics
• Insulin dose requirements will decrease as kidney disease progresses

Types of insulin

• Insulin, short acting, SC, three times daily, 30 minutes before meals
  • Regular human insulin
  • Onset of action: 30 minutes
  • Peak action: 2–5 hours
  • Duration of action: 5–8 hours
• Insulin, intermediate acting, SC, once or twice daily usually at night at bedtime, approximately 8 hours before breakfast
  • Intermediate acting insulin
  • Onset of action: 1–3 hours
  • Peak action: 6–12 hours
  • Duration of action: 16–24 hours
• Insulin, biphasic, SC, once or twice daily
  • Mixtures of regular human insulin and intermediate acting insulin in different proportions, e.g.  30/70 (30% regular insulin and 70% intermediate acting insulin)
  • Onset of action: 30 minutes
  • Peak action: 2–12 hours
  • Duration of action: 16–24 hours

INSULIN REGIMENS

Basal bolus regimen

All type 1 diabetics should preferentially be managed with the “basal bolus regimen” i.e. combined intermediate-acting (basal) and short-acting insulin (bolus). This consists of pre-meal, short acting insulin and bedtime intermediate acting insulin not later than 22h00.

The initial total daily insulin dose:

• 0.6 units/kg body weight

The total dose is divided into:

• 40–50% basal insulin
• The rest as bolus insulin, split equally before each meal

Adjust dose on an individual basis.

Pre-mixed insulin

Twice daily pre-mixed insulin, i.e. a mixture of intermediate- or short acting insulin provides adequate control, when used with at least daily blood glucose monitoring. It is a practical option for patients who cannot monitor blood glucose frequently.

Education related to insulin therapy

• Types of insulin
• Injection technique and sites of injection
• Insulin storage
• Recognition and treatment of acute complications, e.g. hypoglycaemia and hyperglycaemia
• Diet:
  • Meal frequency, as this varies according to the type and frequency of insulin, e.g. patients may need a snack at night, about 3–4 hours after the evening meal
  • Consistent carbohydrate intake for patient receiving fixed mealtime doses of insulin
• Self-monitoring of blood glucose and how to self-adjust insulin doses

Drawing up insulin from vials

• Clean the top of the insulin bottle with an antiseptic swab
• Draw air into the syringe to the number of marks of insulin required and inject this into the bottle; then draw the required dose of insulin into the syringe
• Before withdrawing the needle from the insulin bottle, expel the air bubble if one has formed

Injection technique

• The skin need not be specially cleaned
• Repeated application of antiseptics hardens the skin
• Stretching the skin at the injection site is the best way to obtain a painless injection. In thin people it may be necessary to pinch the skin between thumb and forefinger of one hand
• The needle should be inserted briskly at almost 90 degrees to the skin to almost its whole length (needles are usually 0.6–1.2 cm long)
• Inject the insulin
• To avoid insulin leakage, wait 5–10 seconds before withdrawing the needle
• Injection sites must be rotated to avoid lipohypertrophy

Prefilled pens and cartridges

• In visually impaired patients and arthritic patients, prefilled pens and cartridges may be used

Home blood glucose monitoring

• Patients on basal/ bolus insulin should initially measure glucose 3-4 times daily
• Once patient is stable, reduce the frequency of monitoring

LoE:III

REFERRAL

• All patients

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Standard Treatment Guidelines and Essential Medicines List for South Africa, Primary Healthcare Level, 2024 Edition