Insulin & T1DM

Typical features of T1DM

Hyperglycaemia (>11mmol/L). Ketosis. Rapid weight loss. BMI <25 kg/m2. Age <50yrs. Family history of autoimmune disease.

How often should T1DM patients monitor their blood glucose?

At least 4 times a day (including before each meal and before bed)

T1DM blood glucose targets: on waking (fasting)

5-7mmol/L on waking (fasting)

T1DM blood glucose targets: before meals other than breakfast

4-7mmol/L

T1DM blood glucose targets: at least 90mins after eating

5-9mmol/L

T1DM blood glucose target: when driving

5mmol/L

T1DM blood glucose target: bedtime

Agree with patient, taking into account the last meal & its related insulin dose

Can T1DM be treated with antidiabetics?

No, T1DM is treated with insulin.

The different possible insulin regimens for T1DM

Multiple daily injection basal-bolus insulin regimens. Mixed (biphasic) regimen. Continuous subcutaneous insulin infusion (insulin pump).

First-line insulin regimen for T1DM

Multiple daily injection basal-bolus insulin regimens

Describe the multiple daily injection basal-bolus insulin regimen

Basal (long /intermediate acting insulin) once or twice daily. Bolus (short-acting insulin) before meals.

First- and second-line basal insulins and their frequency of administration

First line: detemir twice daily. Second line: glargine once daily.

Describe the biphasic mixtures insulin regimen

Short-acting mixed with intermediate insulin injected 1-3 times daily

What T1DM patients may be suitable for continuous s/c insulin infusions (insulin pump)?

Adults who suffer disabling hypoglycaemias and/or have uncontrolled hypoglycaemia

Increase or decrease insulin: Infection

Increase insulin

Increase or decrease insulin: Stress

Increase insulin

Increase or decrease insulin: Trauma

Increase insulin

Increase or decrease insulin: Physical activity

Decrease insulin

Increase or decrease insulin: Intercurrent illness

Decrease insulin

Increase or decrease insulin: Reduced food intake

Decrease insulin

Increase or decrease insulin: Impaired renal function

Decrease insulin

Increase or decrease insulin: Certain endocrine disorders (e.g. thyroid disorders, coeliac disease, Addison’s disease)

Decrease insulin

What areas of the body should insulin be injected in?

Body areas with plenty of subcutaneous fat (abdomen, outer thighs, buttocks)

Compare insulin absorption rate between abdomen & outer thighs/buttocks

Abdomen: fastest absorption rate. Outer thigh/buttocks: slower absorption.

Consequence of not rotating insulin injection sites

Lipohypertrophy → erratic insulin absorption → poorer glucose control

!MHRA Alert! What condition can injecting insulin lead to? How can patients reduce their risk of developing it?

Cutaneous amyloidosis (amyloid proteins deposits under the skin). Rotate injection sites.

!NHS Never Event! Describe the never event associated with insulin & how to prevent it.

Overdose of insulin due to abbreviations or incorrect devices. The words “unit” or “international units” should not be abbreviated. Do not withdraw insulin from an insulin pen/pen refill & administer using a syringe and needle.

Describe soluble insulin (including examples, when to inject, onset, peak & duration of action)

Human, Bovine, Porcine. Inject 15-30mins before meals. 30-60mins onset of action. Peak action 1-4hrs. Up to 9hrs duration of action.

Describe rapid-acting insulins (including examples, when to inject, onset & duration of action

Lispro, Aspart, Glulisine (Remember they don't LAG). Inject immediately before food. <15mins onset of action. 2-5hrs duration of action.

Which brand of rapid acting insulin is faster and why

Fiasp

(Because there’s an addition of vitamin B3, that makes Fiasp faster than Novorapid)

Describe intermediate insulin (including examples, onset, peak and duration of action)

Isophane (Remember I for Intermediate). Biphasic insulin. 1-2hrs onset of action. Peak action 3-12hrs. 11-24hrs duration of action.

Describe long-acting insulins (including examples, when to inject, onset & duration of action)

Detemir, Degludec, Glargine (Remember DDGL - Don't Do Glucose Ladies). Inject once daily (detemir twice daily). 2-4 days to reach steady state. Up to 36hrs duration of action.

What are biphasic insulins?

Pre-mixed insulin preparations with various combos of short- and intermediate-acting insulin.

When should biphasic insulins be injected?

Immediately before meals (e.g. before breakfast & evening meal)

What types of insulin fall under "short-acting insulins"?

Soluble & rapid-acting insulin

What routine practice should be avoided for rapid-acting insulin & why?

Routine use of post-meal injections - associated with poorer glucose control, increased risk of high postprandial-glucose concentration, and subsequent hypo

Which long-acting insulin should be injected twice daily?

Detemir