Type 2 diabetes – Insulin therapy

Insulin is a polypeptide hormone mainly secreted by beta cells in the islets of Langerhans of the pancreas. First used in 1922 in Toronto by Canadian researchers who demonstrated a physiological response to injected animal insulin in a patient with Type 1 diabetes Human insulin by recombinant DNA technology has been available since 1980s – now beef or pork insulin are rarely used and not commercially available in several countries as US

 

Insulin types

 

Rapid acting this is intended to cover post meal glucose rise – injected with food ( can be administered after food if it is not known how much carbohydrate is being consumed )

 

Short acting this covers post meal rise in blood glucose injected 15-30 mins before meal examples of short acting Human insulins include Actrapid , Humulin S and Insuman Rapid

 

Intermediate acting – also called BASAL insulins function is to provide a relatively steady supply of insulin to maintain bl glucose levels overnight and between meals NPH ( traditional isophane cloudy insulins ) are suspension of insulin with protamine and must be resuspended before use Isophane insulin or NPH , this would be suitable for cases where once daily dosing is desirable for e.g district nurse administration can be given once or twice daily , before breakfast , at bedtime or both

 

Fixed mixtures 
( of rapid / short acting and intermediate acting insulin ) suitable to cover post meal rise in glucose. For patients with regular meal pattern / lifestyle pre-mixed Human insulins include Humulin M3 , Insuman Comb 15/25/50 pre-mixed analogues include Novomix 30 , Humalog mix 25/50

 

Long acting- once daily dosing reduced risk of hypoglycemia ( often called peakless ) examples of long acting analogues inlcude Levemir , Lantus , Abasaglar , Semglee

 

Ultra long acting – once daily useful when timing of insulin injection is not at a fixed time every 24 hrs Examples of ultra long acting insulins include Tresiba and Toujeo

 

Insulin analogues – Analogue insulins -sub group of human insulin , it is laboratory made ( as is human insulin ) but genetically altered to create a more rapid acting or more uniformly acting form of insulin ( Diabetes UK )

 

Indications – poor control and marked symptoms as polyuria , polydipsia and unintended weight loss poor control despite optimum other antidiabetes treatment suboptimal control in those who are higher risk of complications e.g young age intercurrent illness patient commence on steroid therapy when it is not easy to distinguish between diabetes types pancreatic insufficiency

 

Basal supplement

 
intermediate to long acting , Prandial bolus


 of short or rapid acting insulin , Pre-mixed

A combination of intermediate acting with short-acting or rapid acting insulin

 

Basal insulin – This is use of intermediate or long-acting insulin which is injected once daily ( usually bedtime ) with the intention to keep blood glucose levels stable during periods of fasting ( e.g when sleeping )

 

Prandial – This is use of short or rapid acting insulin which is injected at mealtime to control post-prandial ie after meal rise in glucose levels or for short term correction of meal related hyperglycemia

 

Pre-mixed – Mixture of short acting insulin or rapid acting insulin analogue with a longer acting protaminated version of the same insulin in a fixed ratio intended to provide a peak of activity to tackle postprandial hyperglycemia as well as a basal component to tackle hyperglycemia between meals or overnight with a single injection

 

Basal bolus – Intensive regimen with 3 pre-prandial doses of short/ rapid acting insulin and a bedtime dose of intermediate or long acting insulin. This may be suitable for those who do not have a stable daily routine ( time and dose of insulin can be altered according to meal time and its carbohydrate content )

 

Adverse effects – weight gain ( dose related ) hypoglycemia lipohypertrophy local injection site reactions allergic reactions

 

NICE guidance

 

Structured Programme using active insulin dose titration inj technique , site rotation support via telephone self monitoring dose titration to target levels dietary advice driving guidance as per DVLA requirement managing hypoglycemia how to manage acute changes in plasma gl control

 

Metformin – advice to continue on metformin unless any contraindications or intolerance

 

Insulin NPH – offer NPH insulin ( Neutral protamine Hagedorn ) injected once or twice daily as per need NPH is intermediate acting insulin most widely used basal insulin that simulates the physiological basal insulin action ADA recommended dose is 0.1 to 0.2 units / kg /day s/c Starting dose – minimum should be 10 units and up to 15-20 units when given at bed time this will control fasting hyperglycemia

 

Insulin NPH
+ 
short acting insulin Consider using NPH + short acting insulin particularly if the HbA1c is > 9.0 either separately or as a pre-mixed ( biphasic ) human insulin preparation

 

Use insulin Detemir or Insulin Glargine instead
 of NPH if patient is not able to administer insulin themselves OR they have suffered with recurrent symptomatic hypoglycemic episodes OR they would otherwise need twice daily NPH insulin injections in combination with oral hypoglycemics insulin detemir and glargine are long lasting recombinant versions of human insulin ( insulin analogue )

 

Consider pre-mixed
 ( biphasic ) preparations that include short acting insulin analogues , rather than short acting human insulin preparations if they prefer injecting insulin immediately before a meal OR hypoglycemia is a problem OR blood glucose levels rise markedly after meals

 

Consider switching to insulin detemir or insulin glargine from NPH insulin HbA1c target not reached because of significant hypoglycemia OR they experience significant hypoglycemia on NPH insulin irrespective of the level of HbA1c OR who cannot use the device safely for NPH insulin those who cannot administer themselves and reducing the number of daily injections is desirable.

 

monitor those on a basal insulin regimen ( NPH , detemir or glargine ) if they need short acting insulin before meals ( or a pre-mixed biphasic insulin ) monitor those on pre-mixed ( biphasic ) insulin if they need further short acting insulin before meals or a change to a basal-bolus regimen with NPH/detemir/glargine insulin.

 

standard insulin is 100 Units / mL insulin is prescribed by brand name individualized treatment insulin initiation checklist manufacturers produce insulin pen devices
( in different colour ) which are compatible with cartridges containing their own insulin and these are not interchangeable generally insulin’s come in a 10 mL vial for use with a syringe , in 3 mL cartridges for use in durable pens , or 3 mL disposable pens needle come in range from 4 mm to 12.7 mm insulin therapy typically reduces HbA1c by 1.5 to 3.5 percentage points dose adjustment is guided by regular and targeted blood glucose monitoring patients should check fasting blood glucose ( before breakfast ) every day.

REFERENCES

1. Royal College of Nursing Starting Injectible Treatments in Adults with Type 2 Diabetes 3rd Edition Clinical Professional Resource
2. Hill J (2015) Insulin therapy in type 2 diabetes. Diabetes & Primary Care 17: 252–6
3. Type 2 diabetes in adults : management NICE Guideline 28 Updated March 2022 Recommendations | Type 2 diabetes in adults: management | Guidance | NICE
4. Type 2 Diabetes insulin therapy CEP Providers Type 2 Diabetes: Insulin Therapy | Centre for Effective Practice – Digital Tools (cep.health)
5. Guidelines for Insulin Initiation and Adjustment in Primary Care in Patients with Type 2 Diabetes: for the Guidance of Diabetes Specialist Nurses
   NHS Greater Glasgow & Clyde Managed Clinical Network for Diabetes Microsoft Word – GUIDELINES_FOR_INSULIN_INITIATION-July_2013-Update-Final.doc (nhsggc.org.uk)
6. Saleem F, Sharma A. NPH Insulin. [Updated 2021 Jun 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549860/