Type 2 diabetes accounts for approximately 90% of the total UK diabetes population of around 4.3 million people, and this number is set to exceed 5.5 million by 2030 (Wicher et al, 2020; Diabetes UK, 2023). Most diabetes care occurs in general practice, where an average 20 million diabetes contacts occur annually (Dambha-Miller et al, 2020). This places nurses at the centre of type 2 diabetes management in primary care.
The updated National Institute for Health and Care Excellence (NICE) guideline on type 2 diabetes in adults (NG28) recommends offering treatment on an individual basis, taking into consideration factors such as comorbidities, contraindications, symptomatic hyperglycaemia, and weight (NICE, 2022). A combination of lifestyle advice and drug treatment is the corner stone of type 2 diabetes management, and so nurses need to be familiar with these.
NICE guidelines for type 2 diabetes
The pharmacological pathway in the NICE guidelines on T2DM (NG28) is metformin as first line, or a choice of sulfonylurea (SU), pioglitazone, DPP-4 inhibitor, or SGLT-2 inhibitor if metformin not tolerated or contraindicated (NICE, 2022). These three classes of drugs can also be added as second line therapy if the individual's target HbA1c is not achieved. If dual therapy is not achieved with a combination of two drugs, then a third agent is to be added, including a GLP-1 receptor agonist and insulin (NICE, 2022).
When to start insulin
Nurses need to be aware of when their patients may require insulin to support them in achieving their target glycaemic levels, as there is clear evidence that good glycaemic control reduces long-term micro and macro-vascular complications (Martinez et al, 2021; Khunti and Aroda, 2022). For most people with type 2 diabetes, insulin usually comes after other agents (see above) have been tried and have been insufficiently effective or not tolerated. Insulin can be a third- or fourth-line option for glycaemic control.
The NICE guidelines for type 2 diabetes (2022) advise that for symptomatic hyperglycaemia, insulin or an SU, such as gliclazide or glipizide should be considered. Symptomatic hyperglycaemia refers to those osmotic symptoms such as polyuria, polydipsia, blurry vision and possibly dehydration and weight loss, caused by glucose toxicity and insufficient insulin to reduce the glucose levels (Chao and Hirsch, 2018). These are symptoms that nurses need to be mindful of when reviewing their patients in clinic.
When symptomatic, the individual's HbA1c is likely to be above 75 mmol/mol (> 9%) (NICE, 2022). In such cases, although SUs have high efficacy in terms of their rapid onset of action, they should be used cautiously to avoid hypoglycaemia, particularly in older adults, and should be avoided where possible in severe renal impairment; e.g. eGFR < 30 ml/min (Joint Formulary Committee, 2023a; Kalra et al, 2015). Nurses also need to be aware that people may also need insulin short term during intercurrent illness or for steroid-induced hyperglycaemia/diabetes, particularly if an SU is not appropriate or has been ineffective.
For steroids, the choice of insulin depends on the patient's glucose profile, which for a once-daily morning dose could be an intermediate-acting insulin, because like the steroids its peak action is 4–8 hours after administration. They may also require a rapid-acting insulin, so nurses need to review the individual's blood glucose levels regularly, particularly if the steroid doses are adjusted at intervals (Joint British Diabetes Societies for Inpatient Care, 2021).
What insulin to start
Given the wide range of insulin types available, it is useful for nurses to know what insulin to initiate for their patients. The NICE NG28 guidelines recommend that if the individual's HbA1c is 75 mmol/mol (9%) or higher, to start a once- or twice-daily basal insulin such as an isophane/NPH insulin or an analogue basal. If the individual's glucose rises significantly after meals, they may require a pre-mixed/biphasic insulin and, ultimately, basal bolus therapy (NICE, 2022).
When explaining the profile of insulin to their patients, practice nurses can advise that analogue basal insulins have had their structure adjusted to prolong their half-life and fast-acting analogues have had their structure altered for rapid absorption (Joint Formulary Committee, 2023).
Reluctance to commence insulin
Various studies have shown a reluctance, either from people living with diabetes or with healthcare practitioners, to initiate insulin therapy.
Patient factors
A study by Abu Hassan et al (2013) revealed that patients felt a sense of failure when they had to resort to insulin after years of taking tablets. This is echoed by Brod et al (2014) and Ellis et al (2018), where patients viewed insulin as evidence of personal failure to self-manage their diabetes. Brod et al (2009) coined the phrase ‘psychological insulin resistance’ to describe the reluctance to insulin use.
Nurses need to introduce the subject of insulin as a future treatment option as early as possible, explaining that type 2 diabetes is characterised by declining insulin production, so that when the time to initiate insulin arrives it is expected and, hopefully, viewed as a way of replacing their endogenous supply.
A major insulin deterrent for people living with diabetes is the fear of needles and injections, which may originate from previous experiences, reports from friends and family or erroneous perceptions about insulin injection devices (Abu Hassan, 2013; Brod et al, 2014; Wibisoni et al, 2017; Ellis et al, 2018). As part of the patient's primary healthcare team, nurses are well placed to identify the source of their fear, provide a personalised insulin education plan, and provide ongoing support, alongside the individual's support network (Abu Hassan et al, 2013; Kruger et al, 2015; Wibisoni et al, 2018). Table 1 provides a summary of strategies that can be used by practice nurses to help manage fear of injections.
Table 1. Strategies to manage fear of injections
| Strategy | Actions |
|---|---|
| Identify the barriers |
|
| Creating a ‘fear ladder’ Patient to give fear rating to listed items |
|
| Climb the fear ladder |
|
| Continuous education |
|
| Follow-up/referral |
|
https://www.anxietycanada.com/sites/default/files/Examples_of_Fear_Ladders.pdf https://www.guysandstthomas.nhs.uk/health-information/needle-phobia-and-overcoming-your-fear
Health professional factors
Therapeutic or clinical inertia is the failure to start a therapy or its intensification/non-intensification when appropriate (Andreozzi et al, 2020). A focused literature review by Khunti and Jones (2016) identified that while inertia could be attributed to patients, delays in initiating insulin include health professionals lacking confidence in managing newer oral agents alongside insulin and being unfamiliar with latest guidelines.
An effective strategy that nurses could use is holding regular multi-disciplinary case management reviews (virtual ward rounds) with GPs and pharmacist colleagues to discuss complex cases, and as a learning opportunity to ensure they remain up to date with current guidelines.
Side-effects of insulin
Weight gain
Another reason for delaying insulin therapy by both health professionals and patients in type 2 diabetes is its weight-gaining potential, especially for those who are already overweight (Russell-Jones and Khan, 2007). Given that weight reduction improves long-term glycaemic control and reduces cardiovascular risk, weight gain can be demoralising to people living with diabetes (Look AHEAD Research Group, 2010).
One of the strategies nurses can use is to promote weight loss by encouraging physical activity in their patients, along with individualised dietary changes, and dietitian support if needed (Russell-Jones and Khan, 2007). Where appropriate, and if tolerated, nurses can also introduce weight-sparing diabetes medication alongside insulin, such as GLP1 receptor agonists, which regulate satiety signals and suppress appetite and SGLT2-inhibitors which act promote renal glucose secretion (Provulis et al, 2011; Xu and Rajaratnam 2017).
Lipohypertrophy
Lipohypertrophy, the thickening and hardening of fat tissue at an over-used injection site is another complication of insulin treatment (Misnikova et al, 2011) and is associated with site pain, variability of insulin absorption and scarring. Longer needle size, re-use of needles and infrequent injection site rotation are the main causes identified for the problem (Misnikova et al, 2011; Cunningham and McKenna, 2013; Al Ajlouni et al, 2015). As part of insulin education, nurses are encouraged to conduct routine reviews to reiterate good insulin injection practice, including single needle use (Cunningham and McKenna, 2013) and to use practical tools to encourage site rotation such as the BBraun rotation templates (BBraun, nd).
During the review, they can also inspect and palpate injection sites for lipohypertrophy and teach patients how to examine their injection sites regularly. Where lipohypertrophy has occurred, nurses need to reassure the individual that these will likely resolve in a number of months and provide them with advice on adjusting their insulin doses when using healthy sites to prevent hypoglycaemia.
Hypoglycaemia
Hypoglycaemia (or hypo) is another deterrent to starting insulin, as well as a side-effect of insulin, so patient education is key. Nurses should outline the symptoms, causes and treatment of hypoglycaemia by using visual resources such as the TREND UK (2018) hypoglycaemia leaflets. Regular blood glucose monitoring is an important factor in identifying and managing hypos so nurses need to ensure that individuals taking insulin have a functioning blood glucose meter and know how to use it, interpret the results and what action to take.
Frequent hypoglycaemia is a red flag for nurses, who need to review the patient and investigate the cause(s) and come up with solutions in partnership with the patient. Strain et al (2021) identify people at high risk of hypos to include older adults who may also be frail, may have sustained falls, have declining renal function and may be taking oral diabetes medication with a hypo risk, such as sulphonylureas.
When the practice nurse identifies such individuals, they should discuss and agree an individualised plan to minimise further hypos. Drivers are a group of people who are either reluctant to start insulin or continue it because of the licence restrictions and potential revocation following severe hypos. As a result, there is a tendency to under-report hypos, which nurses should be aware of, doing their best to encourage openness in their patients and reiterating the potential hazards of not acting on hypos.
Another consequence of insulin-related hypos is defensive snacking, which can contribute to glucose variability. This can be discussed as a joint consultation with a dietitian to help the individual in dose adjustment.
Conclusion
Due to the progressive nature of type 2 diabetes, injectable treatment with either a GLP-1RA or insulin will be required for most patients. Despite advances in needle design that have greatly minimised pain, anxiety and fear about injection and needle use remain common, and are major contributors to non-adherence to insulin.
Nurses can help to mitigate barriers to injectable therapy by understanding patient perceptions, improving education, and setting realistic expectations about therapy. Tools and strategies that may help facilitate improved initiation of and acceptance to injectable therapy in patients with type 2 diabetes include the comprehensive assessment of patient fears, appropriate needle selection, patient education, the use of behavioural interventions and follow-up monitoring.