ADA-EASD Diyabet Rehberi… (İng)

ADA-EASD Diabetes Guidance

Authors and Disclosures

Caroline Day

School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK

Conflict of interest statement
There is no conflict of interest.

Corresponding author
Dr Caroline Day School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK Tel: +44 (0)121 204 3898; Fax: +44 0)121 204 3892 E-mail: [email protected]

From The British Journal of Diabetes and Vascular Disease

ADA-EASD Diabetes Guidance

Individualised Treatment of Hyperglycaemia

Caroline Day

Posted: 09/05/2012; British Journal of Diabetes and Vascular Disease. 2012;12(3):146-151. © 2012 Sage Publications, Inc.

Abstract and Introduction

Abstract

Hyperglycaemia is a significant contributor to the morbidity and premature mortality of type 2 diabetes. There are several glucose lowering agents, with each class having a different mechanisms of action, but their utilisation has to be considered within the context of disease pathogenesis; appropriateness of the agent for the patient, patient lifestyle and personal circumstance, and to some extent treatment costs. The most recent joint policy statement from the American Diabetes Association and the European Association for the Study of Diabetes addresses these issues and provides guidance on strategies for a patient centred approach to the implementation of evidence based medicine. Glycaemic targets are flexible, but early intervention, and therapy as intensive as individual circumstance dictates are recommended.

Introduction

In 2006 the ADA-EASD published a consensus algorithm for the management of hyperglycaemia in type 2 diabetes.^[1] This consensus recognised the importance of good glycaemic control in reducing the morbidity and premature mortality associated with type 2 diabetes and emphasised the benefits of early and intensive intervention from diagnosis with specialist input at treatment initiation. In particular the consensus deliberated the risks and benefits of aiming for glycaemic control as near normal as possible and how this might be achieved using the pharmacological agents then available.

It is interesting to recall that in Europe in 2006 metformin and sulphonylureas had been available for nearly 50 years and the TZDs were considered new drugs. In the UK the TZD troglitazone had been both introduced and withdrawn in 1997, due to idiosyncratic liver failure; pioglitazone and rosiglitazone were introduced in 2000 (and the latter was withdrawn in 2010 due to possibly increasing cardiovascular risk, but not death).^[2,3] It is noteworthy that in Europe in 2006 the use of insulin in combination with a TZD was off-label, as was and is the use of TZDs in patients with cardiac failure or a history thereof.^[2] Not all of the pharmacological agents in the diabetes armamentarium were included in the algorithm although the USA additionally had the amylin analogue pramlintide and the GLP-1 agonist exenatide, both of which were introduced in 2005.

It was agreed that if *HbA1c ≥7% then the patient should be moved to the next level of therapy unless individual circumstance strongly indicated otherwise. A summary diagram of the 2006 ADA-EASD algorithm is shown in figure 1.^[1,4]

Figure 1. Summary of 2006 ADA-EASD consensus algorithm for the management of hyperglycaemia in type 2 diabetes. If HbA_1c < 7 % maintain therapy. If HbA_1c ≥7% move promptly to next level.^1,4
Key: SU = sulphonylurea; TZD = thiazolidinedione
* TZD with insulin is off-label in the UK
Reproduced with permission from Bailey et al. Br J Diabete Vasc Dis 2006;6:147–8.

Less than18 months later a consensus statement update was presented online – in print 2008 – which addressed the use of thiazolidinediones, especially the issues surrounding rosiglitazone, and recommended greater caution when using these agents. In particular care was warranted in patients at risk of CHF, and in the USA in patients with CHF.^[5] In the interim the first in class DPP4 inhibitor sitagliptin had become available in the USA and Europe and was included in the listing of ‘other drugs’ with glucose-lowering efficacy.^[5]

The subsequent consensus algorithm, available online in October 2008, stressed the role of lifestyle modification as an ongoing strategy in the management of type 2 diabetes and provided detailed discussion on the newer agents.^[6] It also introduced the concept of two tiers of treatment: tier 1 being the well validated core medications (metformin, sulphonylureas, insulin) and tier 2 including the addition of the less well-validated medications (the TZD pioglitazone and the GLP-1 agonist exenatide).^[6] Interestingly the consensus recommended against the use of rosiglitazone; but this agent is still available in the USA.

Since the 2006 consensus the diabetes therapeutics landscape has changed dramatically with the advent of further novel insulins and several agents which target the incretin system, whilst colesevelam (Welchol®) and a quick release formulation of bromocriptine (Cycloset®) have been introduced as treatments for type 2 diabetes in the USA. In Europe colesevelam is indicated in the treatment of hypercholesterolaemia, and bromocriptine in Parkinson’s disease and hyperprolactinaemic conditions, but neither agent is approved for diabetes. The actions and limitations of the glucose-lowering agents which are not used in Europe are summarised on Table 1.

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Table 1. Actions and limitations of glucose-lowering agents available to treat diabetes in the USA but not Europe

*Most agents may rarely cause hypersensitivity reactions
aTake within 2 hours of waking; bTake with a well balanced meal; cTake at mealtimes↑ = increase; ↓ = decrease; – = no change; ~ = approximately; ? possibly; GI = gastrointestinal; LDL-c = low density lipoprotein cholesterol

However in the 2012 position statement the guiding principles of monotherapy, dual therapy and triple therapy and increasing complexity of insulin strategies, on a background of lifestyle modifications, remain in the quest for optimal glycaemic control.^[7]

*To convert HbA1c % to mmol/mol: [HbA1c% – 2.15] × 10.929 = HbA1c mmol/mol. See Conversion charts, p157

Drugs to Reduce Hyperglycaemia

Several drugs, with different modes of action, are available to reduce hyperglycaemia and they can be broadly divided into those which as monotherapy can cause hypoglycaemia and those which are not associated with neuroglycopenia (Table 1 and Table 2).

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Table 1. Actions and limitations of glucose-lowering agents available to treat diabetes in the USA but not Europe

*Most agents may rarely cause hypersensitivity reactions
aTake within 2 hours of waking; bTake with a well balanced meal; cTake at mealtimes↑ = increase; ↓ = decrease; – = no change; ~ = approximately; ? possibly; GI = gastrointestinal; LDL-c = low density lipoprotein cholesterol

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Table 2. Actions and limitations of current glucose-lowering agents available in the USA and Europe 8

*Most agents may rarely cause hypersensitivity reactions
^arequires presence of circulating insulin
^brequires presence of a functional β-cell mass
^cTake with meals, lessen risk and severity of hypoglycaemia
^dTake with meals rich in complex carbohydrate
↑ = increase; ↓ = decrease; – = no change; ~ = approximately; K+-ATP = Kir 6.2 potassium ion channel/inwardly rectifying potassium channel; DPP-4 = dipeptidyl peptidase-4; GI = gastrointestinal; GLP-1, glucagon-like peptide-1; PPARγ = peroxisome proliferator-activated receptor gamma
Reproduced with permission from Bailey & Day, Br J Diabetes Vasc Dis 2010;10:178–84.

Hypoglycaemic Agents

The hypoglycaemic action of insulin is well established as is the glucose lowering efficacy of the sulphonylureas which act directly on the beta cell to stimulate insulin release. A range of sulphonylureas is available with differing onsets and durations of action as well as different pathways of metabolism and elimination, providing opportunities for selection of the sulphonylurea most suited to the individual patient.

Although the meglitinides (glinides), also directly stimulate insulin release they are less likely to cause hypoglycaemia as they have a very rapid onset and short duration of action. They are often termed prandial insulin releasers, as they should only be taken with food. Despite not being included in any of the algorithms the new consensus notes that it may be appropriate to use a meglitinide instead of a sulphonylurea.^[7]

Antihyperglyaemic Agents

A particular benefit of antihyperglycaemic agents is that they are generally associated with weight loss or weight neutrality, unlike the hypoglycaemic agents which promote weight gain whilst improving glycaemia.

Metformin is the oldest antihyperglycaemic agent and it has a multiplicity of mechanisms and sites of action, the most notable of which is to reduce insulin resistance particularly in the liver whereby hepatic glucose production is decreased but not completely inhibited. The α-glucosidase inhibitors (eg acarbose in the UK) retard the rate of carbohydrate digestion in the small intestine, but are rarely used in the UK and USA – possibly due to patient intolerance of their GI side-effects – as well as limited glucose lowering efficacy. However as noted in the position statement the α-glucosidase inhibitors may be helpful as initial therapy in patients unsuited to metformin.^[7]

The bile acid sequestrant colesevelam,^[9] the dopamine agonist bromocriptine,^[10] and the amylin analogue pramlintide^[11] offer similar opportunity to enhance individualisation of therapy, but have not been included in the main algorithm (Table 1).

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Table 1. Actions and limitations of glucose-lowering agents available to treat diabetes in the USA but not Europe

*Most agents may rarely cause hypersensitivity reactions
aTake within 2 hours of waking; bTake with a well balanced meal; cTake at mealtimes↑ = increase; ↓ = decrease; – = no change; ~ = approximately; ? possibly; GI = gastrointestinal; LDL-c = low density lipoprotein cholesterol

The TZDs, of which only pioglitazone is now licensed in Europe, are PPARγ agonists which enhance insulin sensitivity – notably to increase glucose uptake into muscle and fat.^[2] Unlike the other antihyperglycaemic agents TZDs are associated with weight gain, but this may be partly due to an increase in fluid retention.

There are several DPP4-inhibitors (gliptins) which have varying pharmacokinetic profiles with differing routes of metabolism and elimination, but are all considered weight neutral and can assist weight loss in some patients. These agents enhance the availability of circulating incretins and offer increased opportunity to tailor the prescription to the patient. The GLP-1 receptor agonists/mimetics, which stimulate glucose dependent insulin release, are the antihyperglycaemic agents most strongly associated with weight loss – but the opportunity to use these agents may be compromised by local guidelines; for example the recommendation by NICE that patients have a BMI≥35 kg/m² or a BMI <35kg/m² plus a co-morbidity.^[12] This class of agent, which is an injectable, has been available in the USA since 2005, but only entered Europe in 2007.

Algorithm Agents

The number of glucose lowering agents included in the algorithm has increased with each iteration of the consensus, firstly with the addition of GLP-1 agonists, and now inclusion of DPP4 inhibitors; but those excluded continue to be the alpha-glucosidase inhibitors, meglitinides and pramlintide as well as the more recently introduced colesevelam and bromocriptine.^[7] Figure 2 summarises the therapeutic approaches elucidated in the 2012 position statement.

Figure 2. Algorithmic summary of 2012 ADA-EASD policy statement recommendations for the management of hyperglycaemia in type 2 diabetes. If individualised glycaemic target not achieved, or maintained, move promptly to next therapy level using a patient-centred approach to drug selection
Key: DPP4i = dipeptidylpeptidase 4 inhibitor; GLP-1a = glucagon-like peptide-1 agonist; SU = sulphonylurea; TZD = thiazolidinedione Reproduced with permission from MedEd UK.

Individualisation of Therapy

Increasing recognition of the importance of the patient in the medical decision making has led to the 2012 consensus recommending a patient centred approach.^[7] This is especially pertinent in diabetes where lifestyle choices have such an influence on outcomes that lifestyle is the fundamental and enduring treatment strategy to which pharmaceutical interventions are added. An holistic approach to therapeutic choice is required as the strategy selected has to fit within the constraints of known contraindications, co-medication for additional morbidities and within the diverse demands of a person’s life. Added to this is the benefit:risk assessment associated with each agent, including the debate surrounding macrovascular risk and glycaemic targets, all of which should be considered within the context of the individual.^[13]

This recent policy statement raises these issues and helpfully indicates the main advantages and disadvantages of the different therapeutic classes, their main modes of action and cost implications. All the agents are noted as being of high cost, except the well established 2^nd generation sulphonylureas and metformin which are viewed as low cost and the alpha-glucosidase inhibitors moderately priced, with insulin costs being variable – depending on type and dosage.^[7] The influence of optimal glycaemic management is discussed – an HbA1c > 7% is still considered a ‘call to action’ – with emphasis being placed on the importance of altering this target as required by personal circumstance, for example an HbA1c ~8% may be appropriate in a person susceptible to severe hypoglycaemia or with limited life expectancy, but hyperglycaemic symptoms should be eliminated. An elemental approach to decision making in diagrammatic format provides a framework in which to consider the practicalities and benefits of more or less stringent control in the individual management of hyperglycaemia.^[7,13,14]

Adherence

The role of the patient, particularly in the management of chronic conditions such as diabetes, is being recognised as a fundamental factor for the achievement of optimal outcomes, for it is patients who decide upon their lifestyle choices and extent of adherence to prescribed medication.^[15–17] Indeed it is variously estimated that 36–93% of patients with type 2 diabetes on oral therapy collect <80% of prescribed medication, and adherence declines as the number of antidiabetic medicines, dosing complexity and co-medications increase.^[16,17]

With regard to lifestyle changes and taking medications a greater mutual understanding between prescriber and patient is required. The building of such a therapeutic alliance requires an awareness of the pros and cons of treatment strategies as is necessary for that patient to discuss the strategies with the prescriber. The move towards concordance facilitates patient adherence to the strategy and increases prescriber confidence that the agreed action plan will be implemented.^[17]

When moving from monotherapy to dual therapy – and even triple therapy – the pill burden can be reduced by substituting the two dual therapy agents with a fixed dose single tablet antidiabetic combination – thereby aiding adherence by reducing the pill burden.^[16–18] This approach is not mentioned in the latest consensus although compared to Europe a wide selection of combinations and dosage strengths is available in the USA (mainly metformin + another agent).^[16]

Conclusion

The latest policy statement notes that lifestyle strategies alone may be successful in patients with near-target hyperglycaemia (eg HbA1c <7.5%) and suggests that this approach be offered to well motivated patients.^[7] However in those less likely to implement and adhere to lifestyle changes as well as those with moderate hyperglycaemia, initiation of metformin is recommended. If metformin is inappropriate for the patient then a 2^nd line agent or an α-glucosidase inhibitor should be considered. Despite increased awareness, diabetes is often not diagnosed until later in the pathogenesis of the condition, thus initial therapeutic strategies may be those found at later stages in the treatment pathway. It is appreciated that the disease, not drug failure, necessitates moving to the next step, hence continuation of therapy and the adding of another agent or introduction of increasingly complex insulin regimens to prevent hyperglycaemia and its acute and chronic sequelae.

The recent approach to managing hyperglycaemia might be considered conservative, with the older established – and now less costly – agents being given prominence. This may be due in part to the lack of long-term clinical experience with the newer agents generating a cautious approach; discretion is the better part of valour.

Cardiovascular risk reduction is a major focus of therapy in type 2 diabetes and a considerable contributor to the polypharmacy onto which glucose lowering treatments are added. Type 2 diabetes is a moving target so guidance has to be flexible and adaptable with strategies that can be implemented by the patient. The modern mantra of individualisation is a key issue in the 2012 ADA-EASD policy statement with the focus being on an alliance between the patient and prescriber. The provision of bespoke treatment suited to the patient recognises the person as well as their medical situation. This patient-centred approach empowers patients and enables patient and prescriber to ‘sing from the same hymn sheet’, ideally facilitating patient adherence, which also supports the prescriber to provide optimal treatment.

Mandatory glycaemic targets are not included in the latest treatment algorithm, as this encourages individualisation of strategies; but guidance is supplied. For ongoing treatment in patients who are not achieving their target transfer to the next step should be implemented rapidly. Whilst tight glycaemic control is advocated, there is endorsement of less rigorous targets as demanded by individual circumstance.

Sidebar

Key Messages

• Lifestyle measures are the cornerstones of treatment
• Form a therapeutic alliance with the patient
• Individualise glycaemic targets
• Individualise glucose lowering strategies

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References

1. Nathan DM, Buse, JB, Davidson MB et al. Management of hyperglycaemia in type 2 diabetes: a consensus algorithm for the initiation and adjustment of therapy. A consensus statement from the American Diabetes Association and the European Association for the Study of Diabetes. Diabetologia 2006;49:1711–21, and Diabetes Care 2006;29:1963–72.
2. Bailey CJ, Day C. Thiazolidinediones today. Br J Diabetes Vasc Dis 2001;1:7–13.
3. EASD. Statement on withdrawal of Avandia (rosiglitazone) in Europe from the European Association for the Study of Diabetes (EASD). Sept 2010. http://www.easd.org/easdwebfiles/annualmeeting/46thMeeting/Press/Other/EASDAvandia.pdf (Accessed April 2012)
4. Bailey CJ, Day C, Campbell IW. A consensus algorithm for the treatment of hyperglycaemia in type 2 diabetes. Br J Diabetes Vasc Dis 2006;6:147–8.
5. Nathan DM, Buse JB, Davidson et al. Management of hyperglycaemia in type 2 diabetes: a consensus algorithm for the initiation and adjustment of therapy. Update regarding the thiazolidinediones. Diabetologia 2008;51;8–11 and Diabetes Care 2008;31:173–5.
6. Nathan DM, Buse JB, Davidson MB et al. Medical management of hyperglycaemia in type 2 diabetes: a consensus algorithm for the initiation and adjustment of therapy. Diabetologia 2009;52:17–30 and Diabetes Care 2009;193–203.
7. Inzucchi SE, Bergenstal RM, Buse JB et al. Management of hyperglycaemia in type 2 diabetes: a patient-centred approach. Position statement of the American Diabetes Assoication (ADA) and the European Association for the Study of Diabetes (EASD). Diabetologia 2012;55:1577–96 and Diabetes Care 2012, April 19 epub ahead of print.
8. Bailey CJ, Day C. Glucuretics to treat diabetes. Br J Diabetes Vasc Dis 2010;10:178–84
9. Fonseca VA, Handelsman Y, Staels B. Colesevelam lowers glucose and lipid levels in type 2 diabetes: the clinical evidence. Diabetes Obes Metab 2010; 12: 384–92.
10. Holt RIG, Barnett AH, Bailey CJ. Bromocriptine: old drug, new formulation and new indication. Diabetes Obes Metab 2010;12:1048–57.
11. Ryan G, Briscoe TA, Jobe L. Review of pramlintide as adjunctive therapy in treatment of type 1 and type 2 diabetes. Drug Des Dev Therap 2008;2:203–14.
12. NICE. Liraglutide for the treatment of type 2 diabetes mellitus. TA203. October 2010. http://www.nice.org.uk/nicemedia/live/13248/51313/51313.pdf. (Accessed April 2012)
13. Bergenstal RM, Bailey CJ, Kendall DM. Type 2 diabetes: assessing the relative risks and benefits of glucose-lowering medications. Am J Med 2010;123:(April) 374e9–374e18
14. Ismail-Beigi, Moghissi E, Tiktin M et al. Individualizing glycemic targets in type 2 diabetes mellitus: implications of recent clinical trials. Ann Intern Med 2011;154:554–9.
15. Wientjens WJHM. International charter of rights and responsibilities of people with diabetes. Br J Diabetes Vasc Dis 2009;9:105–6.
16. Bailey CJ, Kodack M. Patient adherence to medication requirements for therapy of type 2 diabetes Int J Clin Pract 2011;65:314–22.
17. Emslie-Simith A, Dowall J, Morris A. The problem of polypharmacy in type 2 diabetes. Br J Diabetes Vasc Dis 2003;3:54–56.
18. Bailey CJ, Day C. Anti-obesity fixed-dose combinations. Br J Diabetes Vasc Dis 2012;12:2–5.

Abbreviations and acronyms
ADA, American Diabetes Association; BMI, body mass index; CHF, congestive heart failure; DPP4, dipeptidylpeptidase 4; EASD, European Association for the Study of Diabetes; GI, gastrointestinal; GLP-1, glucagon-like peptide-1; HbA1c, glycated haemoglobin A1c; NICE, National Institute for Health and Clinical Excellence; PPARγ, peroxisome proliferator activated receptor gamma; TZD, thiazolidinedione

Funding
This research received no specific grant from any funding agency in the public, commercial, or not for-profit sectors.

British Journal of Diabetes and Vascular Disease. 2012;12(3):146-151. © 2012 Sage Publications, Inc.