Monitoring

Acute monitoring of blood glucose

Re-check the patient’s blood glucose after 10-15 minutes and repeat administration of intravenous or oral glucose until the hypoglycaemia has resolved (i.e., repeat administration if blood glucose remains <3.9 mmol/L [<70 mg/dL]).​[1][3][106]

Long-term monitoring

Clinicians should assess any episodes of hypoglycaemia (both confirmed and suspected) and the possibility of impaired awareness of hypoglycaemia at each patient visit.​[1][3][4]​​​ For more information on impaired awareness of hypoglycaemia, see Complications.

Monitoring of blood glucose is key for all patients with type 1 diabetes (and, in practice, any child being treated with insulin).[2][3][4]​​​​​ In particular, patients should monitor their blood glucose at times of particular risk of hypoglycaemia, such as during sleep or prior to exercise.[1] In children, monitoring of blood glucose overnight is particularly important if they have additional risk factors for nocturnal hypoglycaemia, such as younger age, lower HbA1c levels, and previous hypoglycaemia associated with exercise.[1][124]​​​​ A child or young person having recurrent episodes of hypoglycaemia should have increased input from their diabetes team.[38]

Blood glucose monitoring is recommended in adult patients with type 2 diabetes who:[77]​​

  • Have had prior hypoglycaemic episodes

  • Are taking insulin[3][76]​​

  • Drive or operate machinery and use oral medications that increase the patient's risk of hypoglycaemia

  • Are pregnant, or planning to become pregnant.

Hypoglycaemia risk should be considered when setting HbA1c targets for patients with type 2 diabetes, as targets may need to be relaxed if they have experienced severe hypoglycaemic episodes or have reduced hypoglycaemic awareness.[73]

Continuous glucose monitoring (CGM) is the preferred technique to monitor blood glucose for most patients.[3][4][17][38]​​​​[59][76]​​​​​ Patients using CGM and their family or carers should have ongoing education and support in using their device and be encouraged to use it continuously.[38]​ Self-monitoring of blood glucose (SMBG) is an alternative.[3][4][38][59][125]​​​

  • CGM has become increasingly available and is the preferred method of monitoring blood glucose for patients with diabetes who are being treated with insulin, particularly if they are receiving multiple daily injections of insulin or using an insulin pump.[4][17][38]​​[73]​​​​ CGM is also preferred over SMBG in patients with type 2 diabetes who are at risk of or have recurrent hypoglycaemia (e.g., those taking sulfonylureas or those with impaired hypoglycaemia awareness).[4][17][73][125]​​​ In patients treated with insulin, real-time CGM resulted in better glycaemic control and lower rates of hypoglycaemia and emergency department visits or hospitalisation for hypoglycaemia compared with SMBG.[4][125][126]​​​​ The American Association of Clinical Endocrinology strongly recommends CGM for all patients with diabetes treated with intensive insulin therapy, defined as three or more injections of insulin per day or the use of an insulin pump.[76] In a multi-site registry of 3553 paediatric patients with type 1 diabetes, the introduction of CGM was associated with fewer patients experiencing severe hypoglycaemia over a 1-year observation period.[127]​ Be aware, however, that inpatient CGM use is not currently approved by the US Food and Drug Administration (FDA), but does currently have enforcement discretion (i.e., for patients who are at high risk of hypoglycaemia).[17]

  • Even though CGM is the preferred option for most patients, SMBG may still be necessary to validate or confirm blood glucose levels obtained from CGM (such as during exercise, when CGM readings become less accurate).[17][37]​​[38][59]

For more information on general monitoring of diabetes, see the following topics: Type 1 diabetes, Type 2 diabetes in adults, and Type 2 diabetes in children.

Use of this content is subject to our disclaimer