Diabetes type 2 in adults

Last update: November 2023

 

Diabetes is a metabolic disorder that leads to hyperglycaemia.
Type 2 diabetes usually occurs in adults and accounts for 90 to 95% of diabetes cases worldwide. [1] Citation 1. World Health Organization. Classification of Diabetes Mellitus. World Health Organization; 2019 [Accessed October 19, 2023].
https://iris.who.int/handle/10665/325182
Type 2 diabetes can lead to acute complications, as well as chronic complications that result in serious organ damage (cardiovascular events; diabetic retinopathy, neuropathy, nephropathy).

Clinical features

• Few or no symptoms; symptoms of hyperglycaemia may be present: polyuria (frequent urination) and polydypsia (excessive thirst and drinking).
• In rare cases, patients may present with severe hyperglycaemia (impaired consciousness, coma or acute dehydration).

Diagnosis

• Look for diabetes in the event of:
  • symptoms of hyperglycaemia;
  • cardiovascular disorders: stroke, myocardial infarction, hypertension;
  • peripheral neuropathies, foot ulcers, absence of tendon reflexes or peripheral pulse.
• Diagnosis is made on one of the following results a Citation a. Even in symptomatic patients, it is preferable to perform a second blood glucose test to confirm the result. [1] Citation 1. World Health Organization. Classification of Diabetes Mellitus. World Health Organization; 2019 [Accessed October 19, 2023].
  https://iris.who.int/handle/10665/325182 [2] Citation 2. HEARTS D: diagnosis and management of type 2 diabetes [Accessed October 19, 2023].
  https://www.who.int/publications-detail-redirect/who-ucn-ncd-20.1 :

  Tests	Symptomatic patient	Asymptomatic patient
  Fasting blood glucose (a) Citation a. Fasting blood glucose test: performed on patient that has fasted at least 8 hours. Values are the same for venous and capillary blood.	1 fasting blood glucose ≥ 7 mmol/litre  (≥ 126 mg/dl)	2 fasting blood glucose ≥ 7 mmol/litre (≥ 126 mg/dl)
  Random blood glucose (b) Citation b. Random blood glucose test: performed at any moment of the day. Values are for venous blood only.  For asymptomatic patients, it is not recommended to perform 2 random blood glucose tests. If the first test is a random blood glucose, the second test should be a fasting blood glucose.	1 random blood glucose ≥ 11 mmol/litre (≥ 200 mg/dl)	See tablenote  (b) Citation b. Random blood glucose test: performed at any moment of the day. Values are for venous blood only.  For asymptomatic patients, it is not recommended to perform 2 random blood glucose tests. If the first test is a random blood glucose, the second test should be a fasting blood glucose.
  Post-load blood glucose (c) Citation c. Post-load blood glucose test: performed 2 hours after oral ingestion of 75 g glucose (one sachet of 75 g anhydrous glucose powder dissolved in 200 to 300 ml of water, to be drunk within 10 minutes).	1 post-load blood glucose:  on venous blood ≥ 11 mmol/litre (≥ 200 mg/dl)	2 post-load blood glucose: on venous blood  ≥ 11 mmol/litre (≥ 200 mg/dl)
  	or on capillary blood  ≥ 12.2 mmol/litre (≥ 220 mg/dl)	or on capillary blood   ≥ 12.2 mmol/litre (≥ 220 mg/dl)
  Glycated Hb (HbA1c) (d) Citation d. Glycated haemoglobin (HbA1c): reflects average glycaemia over around 3 months.	1 HbA1c ≥ 6.5%	2 HbA1c ≥ 6.5%

• Perform urine dipstick analysis for ketones if:
  • fasting blood glucose ≥ 15 mmol/litre (≥ 270 mg/dl) and symptoms of hyperglycemia,

or

• fasting or random blood glucose ≥ 18 mmol/litre (≥ 325 mg/dl) even without symptoms.

• Refer the patient if acute complications (such as hyperosmolar hyperglycaemia or ketoacidosis) are present.

Treatment 

Glycaemic targets

Fasting blood glucose ≤ 7 mmol/litre (≤ 126 mg/dl) or HbA1c of 7%. [3] Citation 3. Type 2 diabetes in adults: management | Guidance | NICE. Published December 2, 2015 [Accessed October 19, 2023].
https://www.nice.org.uk/guidance/ng28
The closer blood glucose levels remain to these values, the more cardiovascular complications are prevented or delayed.
Depending on the context (healthcare provision) or patient profile (older patient, history of severe hypoglycaemia or long-standing poorly controlled diabetes), HbA1c ≤ 8% [2] Citation 2. HEARTS D: diagnosis and management of type 2 diabetes [Accessed October 19, 2023].
https://www.who.int/publications-detail-redirect/who-ucn-ncd-20.1  is acceptable.
Blood glucose should not fall < 4.5 mmol/litre (or < 80 mg/dl) or HbA1c < 6.5%.

Lifestyle and dietary advice b Citation b. These measures concern all patients regardless of medication prescribed. They can be sufficient alone to normalize blood glucose levels in certain patients.

• Avoid sugared foods and drinks (but no excessive restriction of carbohydrates). 
• High fibre intake; limit animal fats and alcohol.
• Physical activity.
• Weight control. If BMI ≥ 25, try to reduce weight by 5 to 10%.
• Stop smoking.

Pharmacological treatment

First-line treatment metformin PO c Citation c. If metformin is contraindicated or not tolerated, replace with a sulfonylurea. .

The usual dose is 1 to 2 g daily. For information:

Week 1: 500 mg once daily in the morning at breakfast

Week 2: 500 mg 2 times daily (morning and evening) during meals

Increase in increments of 500 mg per week as long as the drug is well tolerated (max. 2 g daily, i.e. 1 g morning and evening).

 

If glycaemic control is not acheived, administer metformin in combination with a sulfonylurea. 

Sulfonylurea doses are adjusted in increments to avoid the risk of hypoglycaemia, based on blood glucose results.

• In patients under 60, glibenclamide PO: 

The usual dose is 5 mg 2 times daily. For information:

Week 1: 2.5 mg once daily in the morning at breakfast

Week 2: 5 mg once daily in the morning at breakfast

Increase in increments of 2.5 mg weekly until fasting blood glucose reaches target levels (max.15 mg daily).

• In patients over 60, gliclazide PO (immediate release tablet): 

The usual dose is 40 to 80 mg 2 times daily. For information:

Weeks 1 and 2: 40 mg once daily in the morning at breakfast

Increase in increments of 40 mg every 2 weeks (weeks 3 and 4: 80 mg once daily in the morning at breakfast) until fasting blood glucose reaches target levels (max. 240 mg daily, i.e. 120 mg morning and evening).

 

If glycaemic control is not acheived with the combination of metformin + a sulfonylurea, continue metformin but replace the sulfonylurea with intermediate-acting insulin SC: start with 0.2 IU/kg at bedtime. The dose is adjusted after measuring fasting blood glucose in the morning. Once blood glucose levels have stabilized, test levels once weekly then after each consultation. Doses of 1 IU/kg/day or more may be necessary to reach glycaemic targets. If the necessary dose is over 0.5 IU/kg/day, administer in 2 injections daily.

Adjustment of intermediate-acting insulin dosage based on blood glucose levels

 

Example for a man weighing 79 kg:
Start with 16 IU per day (79 kg x 0.2 IU).
On D4, blood glucose is 14.6 mmol/litre. Add 4 IU (daily dose of insulin is 20 IU). 
On D8, blood glucose is 10.4 mmol/litre. Add 2 IU (daily dose of insulin is 22 IU). 
On D12, blood glucose is 6.1 mmol/litre. Glycaemic target is reached. 

Surveillance and monitoring

Laboratory surveillance

• Patients on oral hypoglycemic agents: blood glucose test once a month to begin with, then during monitoring visits.
• Patients on insulin: fasting blood glucose test during the dose adjustment phase then, if possible, once weekly, once the insulin dose stabilised. 
• HbA1c if available: every 3 months, then every 6 months if well stabilised.
• Other necessary tests according to comorbidities and chronic complications.

Clinical monitoring

• Routine consultations: check blood pressure (should remain < 140/80 mmHg) and weight, examine feet. Consultations once a month for the first 6 months, then individualised frequency of consultations depending on the patient's characteristics (e.g. every 6 months if the diabetes is well controlled).
• Annual check-up: check for cardiovascular and neurological complications, evaluate renal function (serum creatinine and proteinuria dipstick test), examination of teeth and gums.
• Management of diabetes complications.

Patient education b Citation b. These measures concern all patients regardless of medication prescribed. They can be sufficient alone to normalize blood glucose levels in certain patients.

• Lifestyle and dietary measures (diet, physical activity, etc.).
• Patients on sulfonylurea or insulin therapy: signs of hypoglycaemia/hyperglycaemia and management.
• Patients on insulin therapy: auto-administration (schedule, injection sites and techniques); storage of insulin.
• Patients on insulin therapy or presenting hypoglycaemic episodes [3] Citation 3. Type 2 diabetes in adults: management | Guidance | NICE. Published December 2, 2015 [Accessed October 19, 2023].
  https://www.nice.org.uk/guidance/ng28 : self-monitoring of blood glucose and adjustment of doses at home using a glucometer.
• Patients with sensory neuropathy or peripheral arterial disease: autoexamination of feet; prevention of foot lesions.