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Management of type 2 diabetes

SIGN algorithm for the managment of diabetes

Algorithm for the managment of diabetes

Diagnosis and screening

WHO criteria for diagnosis of diabetes:

  • The presence of diabetic symptoms (polyuria, polydipsia, and unexplained weight loss) plus
    • fasting plasma glucose (FPG) ≥7.0 mmol/l or
    • plasma glucose ≥11.1 mmol/l at 2 hours after a 75g oral glucose load (OGTT)

Lifestyle management

Delivery of lifestyle interventions

  • People with diabetes should be offered lifestyle interventions based on a valid theoretical framework
  • Computer-assisted education packages and telephone prompting should be considered as part of a multidisciplinary lifestyle intervention programme
  • Healthcare professionals should receive training in patient-centred interventions in diabetes

Structured education

  • Structured education programmes should adhere to the principles laid out by the Patient Education Working Group
  • Adults with type 2 diabetes should have access to structured education programmes based upon adult learning theories
  • Children and adolescents should have access to programmes of structured education which have a basis in enhancing problem solving skills

Psychosocial factors

  • Children and adults with type 2 diabetes should be offered psychological interventions (including motivational interviewing, goal setting skills and CBT) to improve glycaemic control in the short and medium term
  • Healthcare professionals working with adults and children with diabetes should refer those with significant psychological problems to services or colleagues with expertise in this area

Self-monitoring of glycaemia 

  • Self-monitoring of blood glucose (SMBG)is recommended for patients with type 2 diabetes who are using insulin where patients have been educated in appropriate alterations in insulin dose
  • Routine SMBG in people with type 2 diabetes is not recommended
  • Routine self-monitoring of urine glucose in people with type 2 diabetes is not recommended
  • SMBG may be considered in the following groups of people with type 2 diabetes who are not using insulin:
    • those at increased risk of hypoglycaemia
    • those experiencing acute illness
    • those undergoing significant changes in pharmacotherapy or fasting, for example, during Ramadan
    • those with unstable or poor glycaemic control (HbA1c >8.0% [64 mmol/mol])
    • those who are pregnant or planning pregnancy

Weight management in type 2 diabetes

  • Offer obese adults with type 2 diabetes individualised interventions to encourage weight loss (including lifestyle, pharmacological or surgical interventions) to improve metabolic control

Smoking cessation

  • Advise all people who smoke to stop and offer support to help facilitate this to minimise cardiovascular and general health risks
  • Offer intensive management plus pharmacological therapies to people with diabetes who wish to stop smoking
  • Healthcare professionals should continue to monitor smoking status in all patient groups

Exercise and physical activity

  • All people should be advised to increase their level of physical activity to achieve current physical activity recommendations and be supported to maintain this level across the lifespan
  • Exercise and physical activity (involving aerobic and/or resistance exercise) should be performed on a regular basis
  • Advice about exercise and physical activity should be individually tailored and diabetes specific and should include implications for glucose management and foot care
  • Individualised advice on avoiding hypoglycaemia when exercising by adjustment of carbohydrate intake, reduction of insulin dose, and choice of injection site, should be given to patients taking insulin
  • People with existing complications of diabetes should seek medical review before embarking on exercise programmes
  • A gradual introduction and initial low intensity of physical activity with slow progressions in volume and intensity should be recommended for sedentary people with diabetes

Healthy eating

  • People with type 2 diabetes can be given dietary choices for achieving weight loss that may also improve glycaemic control. Options include simple caloric restriction, reducing fat intake, consumption of carbohydrates with low rather than high glycaemic index, and restricting the total amount of dietary carbohydrate (a minimum of 50 g per day appears safe for up to 6 months)
  • Overweight individuals and those at high risk of developing diabetes should be encouraged to reduce this risk by lifestyle changes including weight management and physical activity
  • Clinical interventions aimed at dietary change are more likely to be successful if a psychological approach based on a theoretical framework is included


  • People with diabetes can take alcohol in moderation as part of a healthy lifestyle but should aim to keep within the target consumption recommended for people without diabetes

Pharmacological management of glycaemic control in people with type 2 diabetes

Targets for glycaemic control

  • An HbA1c target of 7.0% (53 mmol/mol) among people with type 2 diabetes is reasonable to reduce the risk of microvascular and macrovascular disease. A target of 6.5% (48 mmol/mol) may be appropriate at diagnosis. Targets should be set with individuals in order to balance benefits with harms, in particular hypoglycaemia and weight gain


  • Metformin should be considered as the first-line oral treatment option for people with type 2 diabetes


  • Sulphonylureas should be considered as first-line oral agents in people who are intolerant of, or have contraindications to, metformin
  • Sulphonylureas should be considered as add-on second-line treatment to other oral therapies and may be useful in triple oral therapy
  • Sulphonylurea therapy is associated with hypoglycaemia (caution should be taken in the elderly) and weight gain


  • Pioglitazone should be considered, usually as dual or triple therapy, for lowering HbA1c
  • Pioglitazone should not be used in patients with heart failure
  • The risk of fracture should be considered during long-term use of pioglitazone
  • Patients prescribed pioglitazone should be made aware of the increased risk of peripheral oedema, heart failure, weight gain, bladder cancer, and fractures

Dipeptidyl peptidase-4 inhibitors (DPP-4)

  • DPP-4 inhibitors should be considered, usually as dual or triple therapy, for lowering HbA1c

Sodium glucose co-transporter 2 inhibitors (SGLT2)

  • SGLT2 inhibitors should be considered as an add-on therapy to metformin in people with type 2 diabetes
  • In individuals with type 2 diabetes and established cardiovascular disease, SGLT2 inhibitors with proven cardiovascular benefit (currently empagliflozin and canagliflozin)  should be considered

Glucagon-like peptide-1 (GLP-1) receptor agonists

  • GLP-1 receptor agonist therapy should be considered in people with a body mass index of ≥30 kg/m2 (or ethnicity-adjusted equivalent) in combination with oral glucose-lowering drugs or basal insulin (or both) as third- or fourth-line treatment, when adequate glycaemic control has not been achieved with these drugs
  • GLP-1 receptor agonist therapy should be considered as an alternative to insulin in people for whom treatment with combinations of oral glucose-lowering drugs has been inadequate
  • For individuals with type 2 diabetes and established cardiovascular disease, GLP-1 receptor agonist therapies with proven cardiovascular benefit (currently liraglutide) should be considered


Continuing oral agents when initiating basal insulin

  • Oral metformin therapy should be continued when insulin therapy is initiated to maintain or improve glycaemic control
  • Consider stopping or reducing sulphonylurea therapy when insulin therapy is initiated. The benefits and risks of continuing other glucose-lowering agents should also be reviewed at this time on an individualised basis

Choosing basal insulin

  • Once-daily bedtime neutral protamine hagedorn (NPH) insulin should be used when adding insulin to metformin. Basal insulin analogues should be considered according to hypoglycaemia risk, for example in those who suffer from recurrent episodes of hypoglycaemia or require assistance with insulin injections
  • Careful clinical judgement must be applied to ensure insulin therapy is not delayed inappropriately

Insulin initiation and intensification

  • When commencing insulin therapy, bedtime basal insulin should be initiated and the dose titrated against morning (fasting) glucose. If the HbA1c level does not reach target then addition of prandial insulin should be considered

Intensifying with premixed preparations

  • Aim to optimise insulin dose and regimen to achieve target glycaemia while minimising the risk of hypoglycaemia and weight gain

Intensifying with rapid-acting insulin analogues versus human insulin

  • Soluble human insulin or rapid-acting insulin analogues can be used when intensifying insulin regimens to improve or maintain glycaemic control

Management of diabetic cardiovascular disease

  • Risk factors:
    • smoking
    • dyslipidaemia
    • hypertension
    • hyperglycaemia

Primary prevention

Glycaemic control 

  • Follow recommendations for glycaemic control in type 2 diabetes

Blood pressure lowering

  • Hypertension in people with diabetes should be treated aggressively with lifestyle modification and drug therapy
  • Target diastolic blood pressure in people with diabetes is ≤80 mmHg
  • Target systolic blood pressure in people with diabetes is <130 mmHg
  • Patients with diabetes requiring antihypertensive treatment should be commenced on:
    • an angiotensin-converting enzyme [ACE] inhibitor (angiotensin receptor blockers [ARB] if ACE inhibitor intolerant), or
    • a calcium channel blocker, or
    • a thiazide diuretic
  • Beta blockers and alpha blockers should not normally be used in the initial management of blood pressure in patients with diabetes
  • Low-dose aspirin is not recommended for primary prevention of vascular disease in patients with diabetes

Lipid lowering

  • Lipid-lowering drug therapy with simvastatin 40 mg or atorvastatin 10 mg is recommended for primary prevention in patients with type 2 diabetes aged >40 years regardless of baseline cholesterol

Management of established cardiovascular disease

Acute coronary syndromes

  • Intensive insulin treatment to be continued for at least 24 hours in patients with myocardial infarction
  • Treat patients with an ST elevation immediately with primary percutaneous coronary intervention
  • When primary percutaneous coronary intervention cannot be provided within 90 minutes of diagnosis, patients with an ST elevation acute coronary syndrome should receive immediate thrombolytic therapy
  • Long term aspirin (75 mg per day) should be given routinely
  • In addition to long term aspirin, clopidogrel therapy should be continued for:
    • 3 months in patients with non-ST elevation
    • up to 4 weeks in patients with ST elevation
  • Patients with clinical MI should be maintained on long term beta blocker therapy
  • Patients with clinical MI should be commenced on long term ACE inhibitor therapy within the first 36 hours
  • Consider intensive lipid-lowering therapy with atorvastatin 80 mg for patients with diabetes and acute coronary syndromes, objective evidence of coronary heart disease on angiography, or following coronary revascularisation procedures
  • Consider fibrate treatment in patients who are intolerant of statins

Heart failure

  • ACE inhibitors should be considered in patients with all New York Heart Association (NYHA) functional classes of heart failure due to left ventricular systolic dysfunction
  • All patients with heart failure due to left ventricular systolic dysfunction of all NYHA functional classes should be started on beta blocker therapy as soon as their condition is stable (unless contraindicated by a history of asthma, heart block, or symptomatic hypotension)

Stable angina

  • All patients with stable angina due to atherosclerotic disease should receive long term standard aspirin and statin therapy
  • Consider treatment with ACE inhibitors
  • For patients with diabetes and multivessel disease, coronary artery bypass surgery (CABG) with use of the internal mammary arteries is preferred over percutaneous transluminal coronary angioplasty (PTCA)
  • Patients undergoing angioplasty should be treated with stents where feasible, and receive adjunctive therapy with a platelet glycoprotein IIb/IIIa receptor antagonist
  • Drug-eluting stents are recommended as opposed to bare metal stents in stable coronary heart disease or non-ST elevation MI

Management of kidney disease in diabetes

  • Risk factors:
    • hyperglycaemia
    • raised blood pressure
    • baseline urinary albumin excretion
    • increasing age
    • duration of diabetes
    • smoking
    • genetic predisposition
    • raised cholesterol and triglyceride levels
    • male gender


  • Albumin: creatinine ratio (ACR) should be used to screen for diabetic kidney disease
  • Young people with diabetes should have ACR tested annually from the age of 12 years

Prevention and treatment

  • Individuals with diabetes and mild to moderate chronic kidney disease (CKD) should be managed in a setting that can provide appropriate investigation, monitoring, and intensive clinical management
  • Maintain intensive glycaemic control in people with type 2 diabetes to reduce the risk of developing diabetic kidney disease
  • Reduce proteinuria regardless of baseline urinary protein excretion
  • Reduce blood pressure to the lowest achievable level to slow the rate of decline of glomerular filtration rate and reduce proteinuria
  • Treat people with type 2 diabetes and microalbuminuria with an ACE inhibitor or an ARB irrespective of blood pressure
  • ACE inhibitors and/or ARBs should be used as agents of choice in patients with chronic kidney disease and proteinuria (≥0.5 g/day, approximately equivalent to a protein/creatinine ratio of 50 mg/mmol) to reduce the rate of progression of chronic kidney disease
  • Dietary protein restrictions (<0.8 g/kg/day) are not recommended in patients with early stages of chronic kidney disease (stages 1–3)

Managing anaemia

  • Patients with diabetes and CKD stage 3–5 should have their haemoglobin checked at least annually
  • Consider erythropoiesis stimulating agents in all patients with anaemia of chronic kidney disease, including those with diabetic kidney disease

Prevention of visual impairment

  • Risk factors:
    • poor glycaemic control
    • raised blood pressure
    • longer duration of diabetes
    • microalbuminuria and proteinuria
    • raised triglycerides and lowered haematocrit
    • pregnancy
    • serum cholesterol for macular exudates and oedema
  • Patients with multiple risk factors should be considered at high risk of developing diabetic retinal disease
  • Good glycaemic control (HbA1c ideally around 7% or 53 mmol/mol) and blood pressure control (<130/80 mmHg) should be maintained to prevent onset and progression of diabetic eye disease

Retinal screening

  • Systematic screening for diabetic retinal disease should be provided for all people with diabetes
  • Patients with diabetes with no diabetic retinopathy could be screened every 2 years. All others should be screened at least annually

Type 2 diabetes

  • Screen from diagnosis

Systematic screening

  • Use retinal photography or slit lamp biomicroscopy


  • Retinal photographs should be graded using digital images by an appropriately trained grader


Laser photo-coagulation

  • For all people with:
    • type 2 diabetes with new vessels at the disc or iris
    • new vessels elsewhere with vitreous haemorrhage
    • type 2 diabetes and new vessels elsewhere
  • Patients with severe or very severe non-proliferative diabetic retinopathy should receive close follow-up or laser photocoagulation


  • Patients with tractional retinal detachment threatening the macula
  • Vitrectomy should be considered for severe fibrovascular proliferation

Cataract extractions

  • Cataract extraction should not be delayed
  • Cataract extraction is advised when sight-threatening retinopathy cannot be excluded


  • Community support, maximising disability benefits, low vision aids and training in their use should be provided to people with diabetes and visual impairment

Management of diabetic foot disease

  • Risk factors for peripheral arterial disease include:
    • smoking
    • hypertension, and
    • hypercholesterolaemia
    • Risk factors for foot ulceration include:
    • peripheral arterial disease and peripheral neuropathy
    • previous amputation
    • previous ulceration
    • the presence of callus
    • joint deformity
    • visual/mobility problems, and
    • male gender
  • All patients with diabetes should be screened to assess their risk of developing a foot ulcer


  • The result of a foot screening examination should be entered onto an online screening tool, such as SCI-DC, to provide automatic risk stratification and a recommended management plan, including patient information 
  • Foot care education is recommended as part of a multidisciplinary approach in all patients with diabetes

Management of active foot disease

Antibiotic therapy

  • Treatment of a patient with an infected diabetic foot ulcer and/or osteomyelitis should be commenced immediately with an antibiotic in accordance with local or national protocols. Subsequent antibiotic regimens may be modified with reference to bacteriology and clinical response

Charcot’s foot

  • Suspected Charcot neuroarthropathy of the foot is an emergency and should be referred immediately to the multidisciplinary foot team 

Multidisciplinary foot care

  • Patients with active diabetic foot disease should be referred to a multidisciplinary diabetic foot care service

Painful diabetic peripheral neuropathy

  • The initial treatment of diabetic peripheral neuropathy (DPN) is dependent on individual patient choice, dosing regimens, cost and side-effect profile
  • Consider antidepressants or anticonvulsants for treatment of painful DPN

full guideline available from…

Scottish Intercollegiate Guidelines Network, Gyle Square, 1 South Gyle Crescent, Edinburgh EH12 9EB (Tel – 0131 623 4720)


Scottish Intercollegiate Guideline Network. SIGN 116: Management of diabetes. Edinburgh: SIGN; 2017. (SIGN Guidelines No. 116)

Scottish Intercollegiate Guideline Network. Pharmacological management of glycaemic control in people with type 2 diabetes. Edinburgh: SIGN; 2017. (SIGN Guidelines No. 154)

First included: January 2018