Type 2 Diabetes Mellitus (T2DM)
Background Information
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder caused by insulin resistance and relative insulin deficiency, leading to persistent hyperglycaemia and long-term microvascular and macrovascular complications.
Updated UKMLA guide to type 2 diabetes mellitus based on the latest NICE 2026 guideline: clinical features, complications, diagnosis, and the new comorbidity-guided management pathways.
Definition
T2DM is defined as a chronic metabolic disorder characterised by hyperglycemia resulting from a combination of peripheral insulin resistance and relative insulin deficiency.
Pathophysiology
2 main mechanisms that contribute to T2DM: [Ref]
- Peripheral insulin resistance (initially)
- Pancreatic β-cell dysfunction (usually in later stages)
- Initially, β-cells compensate by increasing insulin secretion
- However, amylin is co-secreted with insulin → with time amylin can misfold and aggregate into amyloid fibrils
- Deposition of amyloid fibrils contributes to β-cell dysfunction and death
The above pathophysiological processes are driven by a combination of genetic predisposition and environmental factors (see risk factors).
Causes and Risk Factors
Genetic factors: [Ref]
- Family history of diabetes (1st-degree relatives) is a strong risk factor
- Ethnicity (Asian, Black African, African Caribbean)
- Polygenic contribution
Environmental factors: [Ref]
- Obesity (esp. central obesity / visceral fat) – most important modifiable risk factor
- Physical inactivity
- Unhealthy diet (high intake of processed meats, sugar-sweetened beverages, low intake of whole grains and fibres)
- Socioeconomic deprivation, low education, and psychosocial stress
Medications (that cause hyperglycaemia): [Ref]
- Systemic glucocorticoids
- Beta blockers
- Thiazide diuretics
- 2nd generation antipsychotics (esp. olanzapine)
- Protease inhibitors (for HIV)
- Tacrolimus
Medical conditions: [Ref]
- Key medical conditions predisposing to T2DM
- History of gestational diabetes or pre-diabetes
- Cardiovascular disease, hypertension, dyslipidaemia
- PCOSPolycystic ovary syndrome
- Endocrine disorders
- Cushing’s syndrome
- Hyperthyroidism
- Acromegaly
- Hyperthyroidism and phaeochromocytoma (but usually mild)
- Pancreatitis disease
- Haemochromatosis
- Chronic pancreatitis and pancreatic cancer
- Cystic fibrosis
Clinical Features
Classic symptoms (NOT specific to T2DM): [Ref]
- “3 Ps” – classic symptoms of hyperglycaemia
- Polyuria
- Polydipsia
- Polyphagia
- Unexplained weight loss
- Fatigue
- Blurred vision
- Recurrent infections (esp. candidiasis) / poor wound healing
Cutaneous signs of peripheral insulin resistance: [Ref]
- Acanthosis nigricans
- Acrochordons (skin tags)
- Central obesity
Be aware that the classic symptoms stated above are NOT specific to any type of diabetes. They are simply consequences of hyperglycaemia affecting various body systems.
Features / factors that suggest T2DM:
- Associated with weight gain and obesity (unlike weight loss in T1DM)
- Onset >50 y/o
- Gradual onset
- Can first present with complications
Complications
Acute Complications
HHSHyperosmolar hyperglycaemia state
- Far more common than DKA in T2DM [Ref]
- See this article for more details
DKADiabetic ketoacidosis
- Rare in T2DM compared to T1DM, but can occur especially in older adults with long-standing T2DM or extreme insulin deficiency [Ref]
- See this article for more details
Chronic Complications
Microvascular complications: [Ref]
- Diabetic retinopathy
- Diabetic nephropathy
- Diabetic neuropathy +/- charcot arthropathy
- Diabetic autonomic neuropathy
- Gastroparesis
- Sexual dysfunction
- Orthostatic hypotension
- Abnormal sweating
Macrovascular disease (from atherosclerosis): [Ref]
- Coronary artery disease
- Cerebral vascular disease
- Peripheral arterial disease
Diabetic foot problems arise from a combination of peripheral arterial disease and diabetic neuropathy
- See this article for more details
Diagnosis
Diagnostic Rules
If hyperglycaemia is confirmed by abnormal biochemical tests (below) +/- classic symptoms, and T2DM is suspected clinically, no further tests are needed to diagnose T2DM.
Be aware of features that are suggestive of T1DM (see this article for details on T1DM):
- Ketosis
- Rapid weight loss
- Onset <50 y/o
- BMI <25 kg/m2
- Personal and/or family history of autoimmune disease
Diabetes mellitus diagnostic rules:
- Typical symptomsWHO lists classic symptoms as: - Polyuria - Polydipsia - Unexplained weight loss Other features: - Fatigue - Blurred vision - Recurrent infections (esp. genital or skin) + 1 abnormal test, or
- Asymptomatic + 2 abnormal tests (same test on different day or 2 different tests on the same day)
The biochemical cut-offs for diagnosing diabetes mellitus are the same regardless of type:
| Test | Diabetes Cut-off |
|---|---|
| Fasting plasma glucose | ≥7.0 mmol/L |
| Random plasma glucose | ≥11.1 mmol/L |
| 2-hour post-oral glucose tolerance test | |
| HbA1c | ≥48 mmol/mol (6.5%) |
A ‘finger prick’ capillary blood glucose level CANNOT be used to diagnose diabetes mellitus.
HbA1c Interpretation
HbA1c should not be used to diagnose diabetes mellitus in the following patient populations: [Ref]
- All children and young people.
- Pregnancy – current or recent (< 2 months).
- Suspected type 1 diabetes, regardless of age
- Short duration of diabetes symptoms (< 2 months)
- Patients at high risk of diabetes who are acutely illIf HbA1c ≥48 mmol/mol, it confirms pre-existing diabetes.
If HbA1c <48 mmol/mol, diabetes cannot be excluded, and the test should be repeated after recovery from the acute episode. - Patients recently taking (for < 2 monthsHbA1c can be used in patients taking such medication long term (i.e. over 2 months) who are not clinically unwell.) medication that may cause rapid glucose rise (e.g., corticosteroids, antipsychotic drugs)
- Acute pancreatic damage or pancreatic surgery
- Renal failure
- Human immunodeficiency virus (HIV) infection
Causes of false HbA1c levels:
| Falsely low HbA1c | Falsely high HbA1c |
|---|---|
|
(↓ RBC lifespan → less time for glycation) |
(↑ RBC lifespan → more time for glycation) |
|
|
Alternative recommended tests if HbA1c monitoring is invalid (due to disturbed erythrocyte turnover, haemoglobinopathies or abnormal haemoglobin type):
- Quality-controlled plasma glucose profiles
Quality-controlled plasma glucose profiles are systematic measurements of plasma glucose taken at standardized times - such as fasting, preprandial, postprandial, and bedtime - using validated laboratory methods or calibrated point-of-care devices. These profiles are used to estimate trends in blood glucose control by providing direct, time-specific data on glycemic excursions and overall glycemic patterns.
- Total glycated haemoglobin estimation
Total glycated haemoglobin estimation is carried out through certain specialised assays which measure all glycated forms of hemoglobin present in the blood, not just HbA1c.
(especially useful if abnormal haemoglobin/haemoglobinopathies) - Blood fructosamine
Fructosamine reflects average glycemia over a shorter period (2–4 weeks) and is not affected by hemoglobin variants or red cell lifespan abnormalities.
Management (New 2026 Guideline)
A separate article is dedicated to the pharmacology and prescribing information for diabetes medications. See Diabetes Medications
Patient Education
General / Conservative Management
Offer structured educational programmes (group programmes preferred)
Encourage the same healthy eating advice as the general population, which includes:
- Eat high-fibre, low-glycaemic-index sources of carbohydrates (e.g. fruit, vegetables, wholegrains, pulses)
- Choose low-fat dairy products
- Eat oily fish
- Control intake of saturated and fatty acids
- Discourage the use of foods marketed specifically for people with diabetes
Advice on other aspects of healthy living:
- Regular physical activity
- Lose weight if overweight / obese
Whenever possible, offer individualised care and advice, taking the person’s needs, culture and beliefs. Be sensitive to their willingness to change and the effects on their quality of life.
For adults with overweight or obesity and type 2 diabetes, low-energy or very-low-energy diets may be appropriate. However, these should be delivered under medical supervision as part of a structured programme, and are not recommended universally for all patients.
Sick Day Rules
Sick day rules are specific instructions given to patients with diabetes (BOTH type I and II) during periods of acute illness (e.g. vomiting, gastroenteritis, upper or lower respiratory tract infections).
The purpose of these sick-day rules are to avoid acute complications like DKADiabetic ketoacidosis. [Ref]
| ALL diabetic patients |
|
| Patients who take insulin | NEVER stop insulin
|
| Patients who take oral medications | Most oral drugs are typically temporarily stopped during acute illness and restarted once the person is feeling better + eating and drinking for 24-28 hours
Not directly relevant, but other medications like ACE inhibitors, ARBs, diuretics, NSAIDs should also be stopped to reduce the risk of AKI (if there is a risk of dehydration) |
Patient should be advised to seek medical advice for potential hospital admission if:
- ↑ Ketone levels (urine ketone >2+ or blood ketones > 3 mmol/L)
- Persistent vomiting (>2 hours)
- Unable to keep oral fluids down
- Signs of severe dehydration
- Hypoglycaemia (unable to maintain blood glucose >3.9 mmol/L)
Monitoring and Targets
Monitoring T2DM
T2DM should be monitored by measuring HbA1c levels:
- Initially, every 3-6 months until HbA1c is stable on current therapy
- Then, every 6 months once stable
If HbA1c monitoring is invalid due to disturbed erythrocyte turnover or abnormal haemoglobin type (see the diagnosis section – HbA1c interpretation for more detail), use one of the following:
- Quality-controlled plasma glucose profiles
- Total glycated haemoglobin estimation (if there are abnormal haemoglobins)
- Fructosamine estimation
Do NOT routinely offer self-monitoring of capillary blood glucose levels, unless:
- The patient is on insulin, or
- There is evidence of hypoglycaemic episodes, or
- The patient is on oral medication that may increase risk of hypoglycaemia while driving / operating machinery, or
- The patient is pregnant or planning to become pregnant (see the Diabetes in Pregnancy article)
Blood Glucose Targets
| Scenario | Target (HbA1c level) |
|---|---|
| Low hypoglycaemic risk therapy only (e.g. metformin) | 48 mmol/mol (6.5%) |
| Any therapy associated with hypoglycaemia risk (e.g. sulfonylureas, insulin) | 53 mmol/mol (7.0%) |
| If HbA1c rises to ≥58 mmol/mol (7.5%) despite current therapy* |
*In addition to increasing the target to 53 mmol/mol, these patients should also have their drug treatment intensified, as outlined in the anti-diabetic medication section below.
Blood glucose target should be individualised whenever possible.
For instance, some patients might benefit from relaxing the HbA1c target if:
- Patients are unlikely to achieve long-term risk reduction benefits (e.g. patients with reduced life expectancy)
- Tight blood glucose control would put them at high risk of developing hypoglycaemia (e.g. high risk of falls, impaired awareness of hypoglycaemia, patient drive / operate machinery as part of their job)
Pharmacological Management (Drug Choices and Algorithm)
Key Prescribing Principles
For patients who are already taking standard-release metformin:
- If not tolerated or the patient prefers → switch to modified-release
- Otherwise, it can be continued
Management of Symptomatic Hyperglycaemia
If a person has symptoms of hyperglycaemia (e.g. polyuria, polydipsia, weight loss):
- Consider insulin or a sulfonylurea for rapid glucose lowering
- Review and rationalise therapy once blood glucose is within the target range
This is typically a short-term strategy (temporary intensification) and does not replace comorbidity-guided pathway selection.
Important: This approach applies to symptomatic hyperglycaemia in clinically stable patients and is not the same as managing acute hyperglycaemic emergencies – Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycaemia State (HHS)
Introducing Multiple Medications
When more than one medication is indicated, they should be introduced in a stepwise manner, checking for tolerability and effectiveness of each medication.
NICE recommends the following:
- Always introduce metformin first
- If an SGLT-2 inhibitor is indicated → start once metformin is at the maximum tolerated dose
- If a GLP-1 agonist or tirzepatide is indicated → start once the SGLT-2 inhibitor is at the maximum tolerated dose
SGLT-2 Inhibitors and Risk of Diabetic Ketoacidosis
Before starting an SGLT-2 inhibitor, assess for risk factors for DKA, including:
- Previous episode of DKA
- Acute intercurrent illness
- Risk of dehydration / volume depletion
- Very low carbohydrate / ketogenic diet
Where possible, address modifiable risk factors before initiating an SGLT-2 inhibitor.
Key Prescribing Cautions / Contraindications
NICE NG28 explicitly highlights the following:
- Prescribing in renal impairment
- Metformin is contraindicated if eGFR <30 mL/min/1.73 m²
- Sulfonylureas should be avoided if eGFR <30 mL/min/1.73 m²
- SGLT-2 inhibitors are generally avoided if eGFR <20 mL/min/1.73 m²
- Medications with a significant risk of hypoglycaemia include sulfonylureas and insulin
- GLP-1 agonist and tirzepatide
- Should NOT be used during pregnancy (timing of discontinuation before pregnancy depends on the specific drug
MHRA advises the following:
- Semaglutide (Wegovy, Ozempic and Rybelsus) = stop at least 2 months before
- Tirzepatide (Mounjaro) = stop at least 1 month before
- Liraglutide = stop just before trying to become pregnant (0 months)
*Contraception should be continued for the above-stated period after stopping the medication.
) - Should be stopped if the person becomes underweight (BMI <18.5 kg/m²)
- Do not combine a GLP-1 receptor agonist or tirzepatide with a DPP-4 inhibitor
- Should NOT be used during pregnancy (timing of discontinuation before pregnancy depends on the specific drug
These drug-specific considerations should be applied alongside the treatment pathways below when selecting and escalating therapy.
For broader prescribing cautions / contraindications, see the Diabetes Medications article.
Overlapping Comorbidities (>1 Comorbidities Present)
When more than one comorbidity is present, NICE does not specify a single priority pathway. Treatment should be individualised using shared decision-making, while applying relevant safety rules and contraindications.
In practice, many pathways align, particularly for heart failure, obesity, and CKD, which all recommend starting with metformin plus an SGLT-2 inhibitor.
Stepwise Treatment Algorithm (Comorbidity-Guided Pathways)
IMPORTANT: atherosclerotic cardiovascular disease (ASCVD) pathway should be prioritised, when applicable.
If the patient develops ASCVD at any point after starting treatment, they should be switched to the ASCVD treatment pathway, regardless of their initial comorbidity group.
The ‘prioritised’ ASCVD pathway would involve:
- Immediately add semaglutide (Ozempic) to existing therapy (regardless of HbA1c level)
- Continue current medications
- Further escalation if HbA1c remains ≥58 mmol/mol (7.5%), by adding one of the following:
- Sulfonylurea, or
- Pioglitazone, or
- Insulin-based treatment
Beyond the ASCVD pathway priority rule, anti-diabetic treatment pathways depend on the presence of comorbidities.
What if more than one condition applies?
-
When more than one comorbidity is present, NICE NG28 does not specify a single priority pathway. Treatment should be individualised using shared decision-making, applying relevant safety rules and contraindications
-
In practice, many pathways align, particularly for heart failure, obesity, and chronic kidney disease, which all recommend starting with metformin plus an SGLT-2 inhibitor
No Relevant Comorbidities
When to step up: If HbA1c remains ≥58 mmol/mol (7.5%) despite current therapy → step up to the next treatment stage
| Step | Treatment | If contraindicated / not tolerated |
|---|---|---|
| 1 | Dual therapy:
|
If metformin not appropriate → SGLT-2 inhibitor monotherapy |
| 2 | Add DPP-4 inhibitor | Proceed to Step 3 |
| 3 | Add one of the following:
|
Choose an alternative within this step |
Obesity
When to step up: If HbA1c remains ≥58 mmol/mol (7.5%) despite current therapy → step up to the next treatment stage
| Step | Treatment | If contraindicated / not tolerated |
|---|---|---|
| 1 | Dual therapy:
|
If metformin not appropriate → SGLT-2 inhibitor monotherapy |
| 2 | Add:
Only add after ≥3 months of starting initial therapy |
If GLP-1 agonist or tirzepatide not appropriate → add DPP-4 inhibitor instead |
| 3 | Add one of the following:
|
Choose an alternative within this step |
Chronic Kidney Disease
Chronic kidney disease is defined as abnormal kidney function / structure for ≥3 months, most commonly indicated by:
- eGFR <60 mL/min/1.73 m², or
- Markers of kidney damage (e.g. urinary ACRAlbumin:creatinine ratio >3 mg/mmol, abnormal histology or imaging, history of kidney transplant)
When to step up: If HbA1c remains ≥58 mmol/mol (7.5%) despite current therapy → step up to the next treatment stage
| Step | eGFR (mL/min/1.73m2) | Treatment | If contraindicated / not tolerated |
|---|---|---|---|
| 1 | ≥30 | Dual therapy:
|
If metformin not appropriate → SGLT-2 inhibitor monotherapy |
| 20–30 | Dual therapy:
|
No alternative specified here | |
| <20 | Monotherapy:
|
If DPP-4 inhibitor not appropriate → pioglitazone OR insulin-based therapy | |
| 2 | (all eGFR levels) | Add DPP-4 inhibitor (if not already used) | Proceed to Step 3 |
| 3 | (all eGFR levels) | Add one of the following:
|
Choose an alternative within this step |
Heart Failure (Any Ejection Fraction)
When to step up: If HbA1c remains ≥58 mmol/mol (7.5%) despite current therapy → step up to the next treatment stage
| Step | Treatment | If contraindicated / not tolerated |
|---|---|---|
| 1 | Dual therapy:
|
If metformin not appropriate → SGLT-2 inhibitor monotherapy |
| 2 | Add DPP-4 inhibitor | Proceed to Step 3 |
| 3 | Add one of the following:
|
Choose an alternative within this step |
Pioglitazone is NOT mentioned in the heart failure pathway at all, reflecting its association with fluid retention and potential to worsen heart failure.
Atherosclerotic Cardiovascular Disease (ASCVD)
Atherosclerotic cardiovascular disease includes:
- Coronary artery disease (e.g. myocardial infarction, unstable angina)
- Cerebrovascular disease (e.g. ischaemic stroke, transient ischaemic attack)
- Peripheral arterial disease
When to step up: If HbA1c remains ≥58 mmol/mol (7.5%) despite current therapy → step up to the next treatment stage
| Step | Treatment | If contraindicated / not tolerated |
|---|---|---|
| 1 | Triple therapy of:
|
If metformin not appropriate → SGLT-2 inhibitor + semaglutide |
| 2 | Add one of the following:
|
Choose an alternative within this step |
Early-Onset T2DM (<40 y/o)
Rationale of this new patient category:
- Early-onset T2DM have a very high lifetime risk of cardiovascular and renal complications, largely due to longer disease duration and a higher prevalence of obesity
- Therefore, early intensive treatment is recommended to reduce long-term complications
When to step up: If HbA1c remains ≥58 mmol/mol (7.5%) despite current therapy → step up to the next treatment stage
| Step | Treatment | If contraindicated / not tolerated |
|---|---|---|
| 1 | Dual therapy:
Also consider early addition of GLP-1 agonist or tirzepatide |
If metformin not appropriate → SGLT-2 inhibitor +/- GLP-1 agonist or tirzepatide |
| 2 | If NOT on GLP-1 agonist or tirzepatide → add GLP-1 agonist or tirzepatide
Otherwise (if already on GLP-1 agonist or tirzepatide) → move straight to Step 3 |
If GLP-1 agonist or tirzepatide not appropriate → add a DPP-4 inhibitor |
| 3 | Add one of the following:
|
Choose an alternative within this step |
Frailty
Frailty is a state of diminished physiological reserve and increased vulnerability to adverse health outcomes.
When to step up: If HbA1c remains ≥58 mmol/mol (7.5%) despite current therapy → step up to the next treatment stage
| Step | Treatment | If contraindicated / not tolerated |
|---|---|---|
| 1 | All patients: offer metformin (modified-release)
Only offer SGLT-2 inhibitor in addition to metformin if the patient’s level of frailty does not place them at risk of adverse events (e.g. hypotension, dehydration) |
If metformin not appropriate →
|
| 2 | Add a DPP-4 inhibitor | Proceed to Step 3 |
| 3 | Add one of the following:
*Sulfonylureas and insulin carry a higher risk of hypoglycaemia and falls in frail adults and should be used with caution. |
Choose an alternative within this step |
This is the least objective treatment pathway for T2DM. Management in frail adults requires significant individualisation, with particular emphasis on minimising hypoglycaemia, falls, and polypharmacy.
NICE emphasis on the importance of medication review to ensure patients are taking the smallest effective number of medications, at the lowest effective dose.
Insulin-Based Treatment
For guidance on when to initiate insulin-based treatment, see the treatment pathway section above.
| Choice of insulin | 1st line: basal insulin regimen
If the HbA1c is ≥75 mmol/mol (9.0%) → consider a basal-bolus insulin regimen Choosing insulin preparationsOnce-daily basal insulin regimens may be particularly suitable where:
Consider pre-mixed insulin if:
|
| Changes to existing oral medications |
|
| Monitoring | ALL patients on insulin should be offered self-monitoring using capillary blood glucose levels.
Intermittently scanned continuous glucose monitoring should be offered, if ANY of the following:
Patients who are using continuous glucose monitoring will still need to take capillary blood glucose measurements, but less often. Click to see rationale |
Assessment/Management of Complications
|
Complication
|
Recommendations from NICE
|
|---|---|
|
Periodontitis
|
|
|
Gastroparesis
|
Consider gastroparesis if there are:
Management of vomiting caused by gastroparesis:
|
|
Painful diabetic neuropathy
|
Manage in line with the Neuropathic pain article
|
|
Autonomic neuropathy
|
Autonomic neuropathy should be suspected if there is:
Be aware that patients with autonomic neuropathy is at increased risk of orthostatic hypotension, particularly when using antihypertensives, volume-depleting drugs and TCATricyclic antidepressants |
|
Diabetic foot problems
|
Manage in line with the Diabetic Foot Problems article
|
|
Erectile dysfunction
|
|
|
Eye disease
|
Refer immediately to local eye screening service upon diagnosis of T2DM |
|
Hypertension
|
Manage in line with the Hypertension (Primary) article
|
|
Cardiovascular Risk (Antiplatelets)
|
Do not offer aspirin or clopidogrel for primary prevention in T2DM patients who do NOT have comorbid cardiovascular disease
For primary and secondary prevention, see the Lipid Lowering Therapy and Cardiovascular Risk Reduction article |
Management (Previous 2022 Guideline)
Rescue Therapy
In acute symptomatic hyperglycaemia, consider sulfonylurea or insulin to quickly lower blood sugar.
Long-Term Management
General / Conservative Management
Dietary advice:
- Eat high-fibre, low-glycaemic-index sources of carbohydrate (e.g. fruit, vegetables, whole grains and pulses)
- Choose low-fat dairy products
- Eat oily fish
- Control intake of saturated and trans-fatty acids
Lifestyle advice:
- Lose weight (if overweight)
- Advice on physical activity
- Smoking cessation
- Limit alcohol intake
IMPORTANT, advice on sick-day rules to avoid acute complications like DKADiabetic ketoacidosis. This is applicable for BOTH type I and II diabetes patients: [Ref]
| ALL diabetic patients |
|
| Patients who take insulin | NEVER stop insulin
|
| Patients who take oral medications | Most oral drugs are typically temporarily stopped during acute illness and restarted once the person is feeling better + eating and drinking for 24-28 hours
Not directly relevant, other medications like ACE inhibitors, ARBs, diuretics, NSAIDs should also be stopped to reduce the risk of AKI (if there is a risk of dehydration) |
Patient should seek medical advice for potential hospital admission if:
- ↑ Ketone levels (urine ketone >2+ or blood ketones > 3 mmol/L)
- Persistent vomiting (>2 hours)
- Unable to keep oral fluids down
- Signs of severe dehydration
- Hypoglycaemia (unable to maintain blood glucose >3.9 mmol/L)
Monitoring and Targets
Blood Glucose Monitoring
T2DM should be monitored via HbA1c levels
- Every 3-6 months initially, and
- Every 6 months, once HbA1c level is stable
HbA1c targets:
- If the patient is on lifestyle only or 1 drug that does not cause hypoglycaemia: HbA1c 48 mmol/mol (6.5%)
- If the patient is on sulfonylurea: HbA1c 53 mmol/mol (7.0%)
- If the patient is on 2 or more drugs: HbA1c 53 mmol/mol (7.0%)
Do not routinely offer self-monitoring blood glucose in T2DM (unlike in T1DM).
Only offer self-monitoring if any of the following:
- Patient is on insulin
- Evidence of hypoglycaemic episodes
- Patient is planning pregnancy / is pregnant
- Patient is on oral medication that may increase risk of hypoglycaemia while driving or operating machinery
Only offer intermittently scanned continuous glucose monitoring to:
- Patients on multiple daily insulin injections, and
- At least 1 of the following
- Recurrent / severe hypoglycaemia
- Impaired hypoglycaemia awareness
- Inability to self-monitor blood glucose by finger prick
Blood Pressure Monitoring
Blood pressure control and monitoring are important, as patients with T2DM are prone to developing diabetic nephropathy.
Blood pressure targets for T2DM are the same as those for diabetic patients
- Unless there is concurrent CKD with a urine ACR ≥70 (however, this is a separate indication)
- Refer to the hypertension article for more details
Pharmacological Management
Note that a lot of students overthink and over complicate this section, focusing too much on when exactly to step up and when exactly to add which drug.
In exams, questions tend to provide clean-cut HbA1c (i.e. within range or above range). Students are largely expected to know:
- Intensify drug treatment if target not met (if within target, usually not necessary)
- Choice of step 1 drug treatment
- Choice of further steps of drug treatment relies mainly on the SGLT-2 inhibitor criteria and the side effect / safety profile of other drugs
An important rule to bear in mind is: at any stage, if the patient meets the criteria for SGLT-2 inhibitor (i.e. develops chronic heart failure / atherosclerotic CVD / QRISK >10%) → consider adding or replacing an existing drug with an SGLT-2 inhibitor.
For instance, if a T2DM patient who has developed heart failure has an HbA1c of 46 mmol/mol (target <48 mmol/mol), and is stable on metformin monotherapy. In strict glycaemic terms, there is no indication to add another drug, as the HbA1c is at target. However, under the “SGLT‑2 rule”, an SGLT‑2 inhibitor should still be considered as an add‑on to metformin because of the new heart failure indication.
Step 1
There are 2 possibilities:
| Patient category | Recommended management |
|---|---|
Patient has ANY of the following:
|
Start dual therapy of:
Do NOT start both at the same time: first start metformin, and once tolerability is confirmed, then start SGLT-2 inhibitor |
| ALL other patients | Start monotherapy of metformin |
Always start with standard-release metformin. If the patient cannot tolerate, then attempt modified-release metformin.
Only if the patient cannot tolerate modified-release metformin, consider an alternative drug
- If the patient meets the criteria for SGLT-2 inhibitor → offer SGLT-2 inhibitor monotherapy
- Otherwise → offer DPP-4 inhibitor / pioglitazone / sulfonylurea
Step 2
If HbA1c remains >58 mmol/mol (7.5%) despite monotherapy → intensify treatment
Offer dual therapy – add ANY of the following to the existing monotherapy:
- DPP-4 inhibitor
- Pioglitazone
- Sulfonylurea
- SGLT-2 inhibitor (only if there is chronic heart failure / atherosclerotic CVD / QRISK >10%)
The only clear-cut indication to add a 2nd drug is if HbA1c ≥58 mmol/mol.
If the patient has an HbA1c that is above the agreed target (usually 48 mmol/mol) but is below 58 mmol/L → NICE guideline does NOT give a clean-cut recommendation
- NICE says that intensification is guided by the individually agreed threshold and shared decision‑making
- In practice, most local pathways treat this as a “grey zone” and recommend 1) optimise lifestyle, 2) up-titrate metformin to maximum dose (2g per day), 3) check adherence etc.
Note that if the patient already established on dual therapy (metformin and SGLT-2 inhibitor) in step 1 (i.e. since they have chronic heart failure / atherosclerotic CVD / QRISK >10%), these patients would skip this step 2 stage if their HbA1c is above target.
Since they are already on dual therapy, they would move down straight to step 3, if their HbA1c is above target.
Step 3
If dual therapy is not controlling HbA1c under the agreed target → consider either of the following:
| Triple therapy (of oral medications) | FIRST, add ANY of the following to existing dual therapy:
Further step up (if triple therapy is not meeting the target): consider switching 1 drug for a GLP-1 mimetic (e.g. liraglutide, semaglutide) if
|
| Insulin-based therapy | Choice of insulin:
Changes to existing oral diabetic medications
|
T2DM and CKD (i.e. Diabetic Nephropathy)
Investigation and Diagnosis
ALL T2DM patients should be tested for CKD with:
- eGFR (creatinine), and
- Urine ACRAlbumin:creatinine ratio (≥3 mg/mmol is defined as clinically important proteinuria)
Management
1st line: offer ACE inhibitor / ARB if urine ACRAlbumin:creatinine ratio >3 mg/mmol (those with T2DM and CKD)
Step up: add SGLT-2 inhibitor (to ACE inhibitor / ARB) if urine ACR >3 mg/mmol
- Exact recommendation: offer if >30 mg/mmol and consider if >3 mg/mmol
DVLA and Diabetes Mellitus
The DVLA guidance on diabetes driving applies to both type 1 and 2 diabetes.
The guidance and restrictions mainly centre around insulin treatment and the occurrence of hypoglycemic episodes, therefore, it is more often applicable to those with T1DM.
When to Notify the DVLA
Inform the DVLA if:
- Diabetes treated with insulin (type 1 / 2) – a must for all patients
- Consider if taking medications that can cause hypoglycaemia (e.g. sulfonylurea)
When to Stop Driving
Situations to stop driving IMMEDIATELY and notify the DVLA if:
- >1 episode of severe hypoglycaemiaHypoglycaemia episode that requires the assistance of another person to treat, because the individual is unable to self-manage. while awake in the past 12 months
- Any episode of severe hypoglycaemiaHypoglycaemia episode that requires the assistance of another person to treat, because the individual is unable to self-manage. while driving
- Patient developed impaired awareness of hypoglycaemia
- Visual / peripheral sensation impairment that impairs driving
Starting insulin for less than 3 months may temporarily bar driving, pending medical advice and DVLA notification.
Blood Glucose Monitoring Requirement
For group 1 drivers (car or motorcycle):
- Check blood glucose at least twice daily on days the person drives
- Check blood glucose just before driving and at intervals no longer than two hours when driving longer journeys
For group 2 drivers (bus, lorry etc.):
- Check blood glucose at least twice daily on both driving and non-driving days
- Must provide 6 weeks of uninterrupted blood glucose records for annual license review
References
NICE guideline Type 2 diabetes in adults: management
NICE CKS Diabetes - type 2