Prescribing nurse: Initiating insulin in type 2 diabetes - how should we go about it?

When insulin is the preferred or most appropriate therapy, when and how should you make the decision - with the patient - to initiate insulin therapy? And how can you overcome the barriers that might prevent you from doing so?

For many years people with type 2 diabetes, whose control had deteriorated on dual therapy faced a simple choice - either go onto insulin or accept worsening control and the long-term consequences of poorly managed diabetes. Even so for many patients the fear of injection and of hypos and the antipathy to the predicted weight gain delayed the decision to move to insulin well beyond the optimum moment. This delay was probably compounded by the reluctance of health professionals to take the steps to initiate insulin in the unwilling patient, together with the fact that initiating insulin was not commonly done in primary care, so the process of conversion involved expensive inpatient stays, and needed planning and time out of their lives. However, times have changed, we do now start insulin in practice, and there are times when insulin is the preferred, or indeed the only appropriate therapy. Of course the diabetes nurse has a wide choice of therapies at her disposal to manage type 2 diabetes, many of which have advantages over insulin both for lifestyle, metabolism and - at times -employment.

WHAT ARE WE TRYING TO DO?

The aims of the practice nurse in diabetes management are to improve the end points of the morbidity and mortality associated with diabetes. This means good blood glucose control, management of weight, of diet and lifestyle, lipid profiles, blood pressure, and - perhaps most importantly of all - sharing choices and responsibility with patients in a meaningful and clinically accurate manner so that they understand and take ownership of their condition and their care. Good diabetes management has been shown to reduce the risk of complications of diabetes.¹ Improved blood pressure and glucose control are central to this.² But according to the National Diabetes Audit (2009-2010), only two thirds of people with T2D achieved the target HbA1c of 58mmol/mol recommended at the time. Overall, 37% of people with diabetes (types 1 and 2) are at high risk of future complications.³

Shouldn't we just do our best?

The current NICE target for HbA1c in people with T2D is generally 48mmol/mol.⁴ NICE recommends that the target HbA1C is set jointly between patient and clinician, after discussion - but this should not allow abdication of responsibilities. The 90-year-old, frail patient may have less to gain in the long term - and more to lose - from very tight control but this is not the same as agreeing a 50-year-old can reasonably let their control drift because they prefer not to use a needle.

DISEASE PROGRESSION

T2D is a progressive condition, characterized by insulin resistance together with progressive loss of insulin-producing beta cells, so that people using oral treatments usually have to escalate treatment over time, and it is common to progress to insulin therapy eventually.5 In the UKPDS, it was estimated that newly-diagnosed patients had 50% of normal insulin secretion, but by 6 years after diagnosis, this had dropped to less than 25%.6 Of course insulin has some issues for both patients and clinicians - we worry about weight gain, the increased risk of hypos and less than ideal lipid profiles, patients worry about needles, paraphernalia, lack of knowledge, loss of freedoms. So what matters most, glycaemic control or body weight and hypos, how do we help people adjust treatment to their lives rather than the other way round, and where do we start?

CURRENT TREATMENTS

The initial treatments for T2D consist of diet and lifestyle measures, and a variety of oral hypoglycaemic agents. Some of these tend to improve metabolic profiles and promote weight loss, and others do the opposite. Most carry some risk of hypos, although for the newer therapies such as gliptins and GLP-1s (which work in a blood glucose dependent manner) this is relatively unlikely. However, the basis for all of these drugs is that they all in some way depend on the body having some of its own insulin in order to function. They may increase secretion, or enhance the body's response - or both.⁷ But as T2D progresses there comes a point where this is not enough and what is needed is in fact, more insulin. Failure to maintain HbA1c levels below 58 mmol/mol despite using a combination of oral antidiabetic drugs, plus or minus GLP-1s (injected GLP agonists like liraglutide) indicates that consideration of insulin therapy is warranted.⁴

WHAT PUTS PATIENTS OFF?

Many patients with T2D who would benefit from insulin supplementation do not receive it, or don't receive it as early as is appropriate.8 Among the barriers to initiating insulin therapy are the following:

Need to change - patients fear insulin will alter their lives for the worse and limit their options and choices, yet the advent of insulin analogues means this is no longer true in the majority of cases, and accurate information is the key.⁸

• Confidence to manage - around half of patients lack the confidence to manage insulin, and perceive it as daunting.⁸
• Sense of failure - patients often view the need for insulin therapy as a sign of failure.⁸
• Disease severity - patients often associate insulin with more severe diabetes, and may also (wrongly) associate it with additional health problems, such as blindness.⁸
• Injection-related anxiety - approximately 50% of patients reporting being fearful of injections.⁸
• Lack of positive gain - less than 10% were aware that insulin therapy had positive attributes, such as improved glycaemic control and energy levels.⁸
• Employment - patients may be reluctant to agree to insulin therapy because of the potential loss of employment or license to drive large goods vehicles or passenger carrying vehicles.⁹
• Unwanted consequences - both patients and healthcare professionals may be reluctant to initiate insulin because of concerns about hypoglycaemia and weight gain.⁹
• Lack of agreement - dissent from patients challenges us and sometimes it is easier to agree. We like to have rapport with, and please our patients and there comes a point in any consultation when we judge we have clarified options enough and the patient is free to choose. Depending on the patient's pre-existing view on insulin we may reach that point too soon at times.

HOW TO OVERCOME BARRIERS

There are a number of strategies we can look at: Find out what the patient's concerns are, and talk them through specifically.

• Consider offering insulin on a trial basis for a month so that patients feel in control.
• Offer intensive early education and support, keeping recommended behavioural changes - such as composition of meals - to a minimum at first, and focussing on the practicalities of self-management of insulin
• Consider insulin pens as they are simpler to use than conventional syringes
• Explain the benefits of insulin clearly, in terms of the patient's overall health and wellbeing.
• Confront fears. Discuss the real risks of hypoglycaemia: severe hypoglycaemia is comparatively rare in T2D, but education on recognising and treating symptoms can reduce the risk of problems.
• Tackle injection phobias. Cognitive behavioural therapy may help to overcome genuine needle phobia, which is uncommon. Explain that most patients - even children - who need to inject, swiftly find that with modern needles this is an easy process, which most people find neither painful nor problematic.
• Offer immediate positives: tell patients that they may notice improvements in energy levels, for example.
• Address concerns about weight gain: discuss support to mitigate against it, and co-dosing with metformin to minimise it.

HYPOGLYCAEMIA

This is worthy of specific discussion, as intensive blood-glucose control is associated with an increased risk of hypoglycaemia, particularly in patients treated with insulin.² Patients also need to be made aware of sick day rules (advice for patients during intercurrent illness), which may enhance their awareness and fear of hypos. However, compared with type 1 diabetes, T2D poses a much lower risk of hypoglycaemia.10 Patients need to understand hypos and what to do if they have one, be made aware of their own warning signs and to have access to oral glucose to combat an impending hypo, with an understanding of how much to use and when.

Risk factors for hypoglycaemia¹⁰

• Missed or delayed meals
• Eating less food at a meal than planned
• Vigorous exercise without carbohydrate compensation
• Taking too much diabetes medication
• Drinking alcohol

Hypoglycemia risks can be minimised with use of insulin analogs; careful timing of injections, meals, and exercise; frequent self-monitoring of blood glucose levels; and patient education about self-adjustment of the insulin dose and management of hypoglycemia.¹⁰

WEIGHT GAIN

Insulin promotes the movement of glucose into cells and its storage as glycogen, and promotes storage of protein and fat⁶ so weight gain is a common side effect of insulin therapy. Weight gain can be moderated by lifestyle measures (increasing exercise and restricting calories), and also by keeping patients on metformin concurrently with their insulin.¹¹ Patients treated with insulin alone gain significantly more weight than those treated with insulin plus metformin (4.4kg versus 0.5kg).² Although weight gain is undesirable, not least because it ultimately worsens other factors such as lipid profiles, mobility and total insulin requirements, avoiding weight gain should not be at the expense of improving glycaemic control. It is possible that in the future other oral therapies will also be used in combination with insulin.

POSITIVE BENEFITS

Insulin improves diabetic control, and in the end where other therapies are failing, insulin is the answer. Our aim is to approximate what nature would do, and insulin is a natural substance. It may also improve cognition and memory.¹² It additionally enables a degree of tight control around dose and food intake, which for some interested patients may result in a greater sense of control. Many diabetic sportsmen monitor their sugars carefully, adjusting their insulins against meals and exercise in order to maintain optimum control with optimum fitness. With modern insulins and insulin analogues, it is entirely possible to adapt insulin use to the patient's ilfe rather than the other way round.

CAN'T I WAIT? I FEEL FINE

Patients with inadequate control often do feel fine, and may want to postpone the decision until their next annual review. Their diet suits them, their control is running just a little bit awry, they are not yet paying the price. Insulin can seem a big step and one to be delayed until they feel ready. But what if it's another year until they feel ready? It's very comfortable to agree with them and let it ride... It certainly makes our day job much easier as the patient is happier, we've shared some options and they've made a decision - haven't we acquitted ourselves in term of the NICE guidance? It does say we should decide on the HbA1C target in discussion with the patient. But is that entirely right if the patient's best interests lie with tighter control? What is the price of delay? Inadequate glycaemic control increases the risk of complications2 and data suggest that on average, patients with T2D in the UK delay insulin for over 11 years after first being prescribed an oral antidiabetic drug,¹³ even though more than 60% of T2D patients do not achieve even a modest HbA1c target of 58mmol/mol.³ This suggests that we are sitting back and taking the easy way out. Failure to begin insulin therapy promptly is likely to result in reduced life expectancy with a compromised quality of life.¹³

CONCLUSION

Times have changed from the days when insulin was started only in hospital, and then only after holding out without it for as long as possible. Insulin is an important part of good care of type 2 diabetes. There are many other therapies to choose from, many of which can be used before moving to insulin and some of which have advantages over it. However insulin is now commonly started in general practice and the choice of insulins, devices and needles is vastly improved. This means there is now a level of control and comfort associated with insulin that is better than anything we have ever had before. On top of this our understanding of the benefits that insulin therapy can bring is also enhanced, and that places the responsibility squarely with us as healthcare professionals to offer patients appropriate guidance, advice and support in making their choices with us. It is not enough simply to opt out and say the patient doesn't want insulin just yet. The evidence is that this is what we have been doing, and we need to be far clearer in terms of what is best for patients and advise accordingly. 

REFERENCES

1. Diabetes UK. Diabetes in the UK 2010: Key statistics on Diabetes. Available at: http://www.diabetes.org.uk/Documents/Reports/Diabetes_in_the_UK_2010.pdf Accessed December 2011
2. UK Prospective Diabetes Study Group. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33) Lancet 1998;352:837-53.
3. NHS Information Centre 2011. National Diabetes Audit Executive Summary 2009-2010. http://www.ic.nhs.uk/webfiles/Services/NCASP/Diabetes/200910%20annual%20report%20documents/National_Diabetes_Audit_Executive_Summary_2009_2010.pdf
4. NICE. Type 2 diabetes: newer agents. CG87. May 2009 (Updated September 2010). Available at: http://guidance.nice.org.uk/CG87/NICEGuidance/pdf/English
5. Diabetes UK. UKPDS - Implications for the care of people with Type 2 diabetes (Jan 1999). Available at: http://www.diabetes.org.uk/ukpds
6. UK Prospective Diabetes Study Group. United Kingdom Prospective Diabetes Study (13): relative efficacy of randomly allocated diet, sulphonylurea, insulin or metformin in patients with newly diagnosed non-insulin dependent diabetes, followed for three years. BMJ 1995;310:83-88 7. Aronoff SL, Berkowitz K, Shreiner B. Glucose metabolism and regulation: beyond insulin and glucagon. Diabetes Spectrum 2004;17:183-90
8. Polonsky WH, Jackson RA: 'What's so tough about taking insulin? Addressing the problem of psychological insulin resistance in type 2 diabetes' Clinical Diabetes 2004. 22;3;147-150.
9. Diabetes.co.uk. Applying for jobs. Available at: http://www.diabetes.org.uk/Guide-to-diabetes/Living_with_diabetes/Employment-and-diabetes-/Applying_for_jobs/
10. Briscoe VJ, Davis SN. Hypoglycemia in Type 1 and Type 2 Diibetes: physiology, pathophysiology, and management. Clinical Diabetes 2006;24:115-21
11. Strowig SM, Avil'es-Santa ML, Raskin P. Comparison of insulin monotherapy and combination therapy with insulin and metformin or insulin and troglitazone in type 2 diabetes. Diabetes Care 2002;25:1691-98
12. Benedict C, Hallschmid M, Hatke A, Schultes B, Fehm HL, Born J, Kern W. (November 2004). "Intranasal insulin improves memory in humans.". Psychoneuroendocrinology 29 (10): 1326-34
13. Goodall G, Sarpong E, Hayes C, et al. The consequences of delaying insulin initiation in UK type 2 diabetes patients failing oral hyperglycaemic agents: a modelling study. BMC Endocrine Disorders 2009;9:19 All websites accessed April 2012