Care recommendations

Self-monitoring of blood glucose

(SMBG)

The main aim of managing both Type 1 and Type 2 diabetes is to achieve blood glucose, blood pressure and lipid levels as near to normal as possible.

People with diabetes are responsible for the management of their diabetes through a programme of self-care including maintaining a healthy lifestyle; self monitoring of blood glucose; concordance with medication regimens, monitoring for symptoms of hypo or hyperglycaemia and signs of long term complications. Self or home monitoring is one of the key tools available to people with diabetes to enable them to do this. Decisions about the method and frequency of testing should be made on an individual basis.

Although self-monitoring of blood glucose (SMBG) monitoring is established clinical practice, the optimal use of the technique has not been established. 

In 2004 Owens et al. (2) published a consensus statement on the use of self-monitoring of blood glucose by people with diabetes, followed in 2005 by further consultation (3). It is recognised that these guidelines were sponsored by a pharmaceutical company. In the absence of clear evidence-based recommendations, Diabetes UK has undertaken further consultation with professionals and people with diabetes, to attain a wider consensus putting people with diabetes at the centre.

These recommendations aim to support the shared decision making process to agree the method and frequency of self-monitoring of blood glucose. They can only be used effectively if combined with continued education and care and ongoing review. They are guidelines and should not be used as a means of restricting access.

Further information: Diabetes UK Position Statement 'Self- monitoring of blood glucose using urine or blood glucose testing' November 2006.

1. Principles to be applied to identify appropriate monitoring strategy for individuals

  • Assess clinical needs and personal circumstances.
  • Information provided about different methods.
  • Discussion about the advantages and disadvantages of different methods between the diabetes team member and person with diabetes.
  • Review and joint agreement of method and frequency of home monitoring.
  • Provision of education about testing methods and how to utilise results to support effective, appropriate and responsible use. If an individual is not able to show how they [intend to] use results to make appropriate lifestyle and/or treatment changes, no additional benefit will be gained.
  • Information provided about different meters and appropriate selection to suit individual needs and circumstances. [People with diabetes on continual peritoneal dialysis (renal treatment) need to take care when selecting a blood glucose meter. Some solutions contact can affect the test strip results and can give false high readings.]
  • Ongoing review of use, effectiveness and recommended changes eg from urine testing to SMBG, as appropriate.
  • Any changes to prescriptions must be based on an individual assessment, review and agreement with the person with diabetes.

2. Blood glucose control and monitoring – blood, urine and HbA1c?

There are advantages and disadvantages with all forms of monitoring in terms of time, expense and convenience. Two trials have shown that regular self blood glucose monitoring in people with Type 2 diabetes reduced overall HbA1c levels and had significant improvement in quality of life (4,5). Evidence suggests that self-monitoring of blood glucose had a slight but significant improvement in long term metabolic control in people with Type 2 diabetes when given in conjunction with counselling on diet and lifestyle (5-7). Including SMBG as an integral part of care and education was found to provide better glycaemic control in non-insulin treated Type 2 diabetes (8). Other studies have contradicted these findings and claim that the performance and frequency of SMBG in people with non-insulin treated Type 2 diabetes did not predict better metabolic control over a long period (9-13). There are currently two methods for self-monitoring: blood and urine. The standardised measurement of longer-term blood glucose control is glycated haemoglobin (HbA1c). The advantages and disadvantages of different monitoring options should be discussed with the person with diabetes. It is important that any joint decision between the individual and their healthcare professional is based on education to inform how the different methods can be used and what actions need to be taken based on results, and informed choice.

3. Table 1: Advantages and disadvantages of monitoring methods

Monitoring method: Glycated haemoglobin (HbA1c)

Advantages
  • National standards recommend that children, young people and adults with Type 1 diabetes be offered HbA1c testing between 2 and 4 times per annum, with more frequent testing if there are concerns about poor control (14).
  • Provides information to monitor overall control, when supported with an integrated diabetes programme, including self-blood glucose monitoring (15).
  • NICE guidelines recommend HbA1c measurements between 2 and 6 monthly for people with Type 2 diabetes, depending on stability of blood glucose control and changes in medications (15).
  • HbA1c monitoring is a valuable indicator of longer-term control and stability of blood glucose that does not require additional self-care requirements.
  • Additional costs can be reduced by using this as the measure to indicate blood glucose stability.

Disadvantages

  • A person with diabetes can have optimal HbA1c results but poor day-to-day control with extremes in blood glucose levels.
  • Day-to-day stability of glucose is only measurable and achievable through home monitoring.
  • Diabetes treatments have become increasingly sophisticated in recent years and consequently more support and education is needed regarding the undertaking of home monitoring and the interpretation of results.
  • Inequitable access to HbA1c testing results in a significant proportion of people with diabetes being unable to access testing meeting national standards (14,15).

Monitoring method: Urine monitoring

Advantages

  • Cheaper and preferred by some people with Type 2 diabetes on a diet and tablet treatment regimen.
  • It does not involve the ‘pricking’ of fingers to obtain blood, which some people can find painful.
  • This requires education to be able to test effectively and interpret and act on the results.
  • It is an effective method of tracking changes in extreme blood glucose measures over time to inform review and changes of medications.

Disadvantages

  • Urine testing is unhelpful for all those using insulin and for some using sulphonylureas. Urine testing cannot distinguish low blood glucose levels and cannot be used to identify a hypoglycaemic event.
  • It is not an accurate or precise measure of high or low blood glucose levels in those with a high or low renal threshold.
  • Because of the time delay between raised blood glucose levels and urine levels, it does not provide real time information about results to inform day-to-day lifestyles and activities.
  • It is not as practical or easy to do a urine test, especially if exercising, travelling or at work.
  • Some people find urine testing unhygienic and distasteful.

Monitoring method: Blood glucose monitoring

Advantages

  • Has long been recommended by health care professionals as a tool to help achieve blood glucose targets and improve self-management (Table 2).
  • It is an effective, sensible and convenient method for the measurement of blood glucose at home, work, when travelling and exercising. 
  • Results are displayed within a matter of seconds.
  • Those who are colour blind can see results more clearly.
  • Those with visual impairments can use talking meters or meters with larger presentation formats.
  • Results of monitoring can be used to track blood glucose levels over a period of time to inform changes in medication; provide information about the effects of food and activity on blood glucose levels; to identify hypo and hyperglycemia and enable prompt action to be taken and; provide information to enable choices about activities such as driving or exercise.
  • It provides ‘real time’ results and so testing gives people the power, motivation and control to take action eg increasing physical activity, altering insulin doses, informing food choices.

Disadvantages

  • There is no consensus about the clinical effectiveness of blood glucose testing using blood glucose meters for people with Type 2 diabetes not treated by insulin.
  • Blood glucose testing is more expensive than either urine testing or no testing at all.
  • Some find that using a lancet device is quite painful and can increase psychological burden (9).
  • Some people find testing demoralising, especially if results are outside the target range.

4. Table 2: Blood glucose self-monitoring and HbA1c targets for people with diabetes (16)

Self-monitored blood
glucose(mmol/l)*

Fasting/pre-prandial:  4-6 mmol/l
Post prandial:               less than 10 mmol/l.
(2 hours after food) 

(targets should be discussed and agreed on a case-by-case basis between the person with diabetes and their healthcare team)

HbA1c:                           <6.5%
                                        (but <7.5% for those at risk of severe
                                         hypoglycaemia)

5. Education and support 

Whether an individual chooses to test their blood glucose or not, or how often they choose to test needs to be discussed and agreed jointly by the individual themselves and their healthcare team (5,6). Education and training should be provided to teach people with diabetes how and when to test, interpret results and take action based on these results. This should be provided as part of structured and ongoing diabetes self-management education programmes with appropriate follow-up (17). Furthermore, people with diabetes should be made aware of where to go to access support if required and informed of what to do if clinical or personal needs for monitoring change. Those unable to undertake SMBG themselves, eg living in nursing homes, may need support from other professionals or carers, who must also be competent in testing to inform management decisions.

The principles of education to inform monitoring are to teach:

  • why it is important to recognise, anticipate and take action on extreme blood glucose levels
  • how to blood test and use the measurements to inform actions and lifestyles
  • how to treat high and low blood glucose levels
  • how to use results to monitor trends, and review changes in treatment, actions and lifestyle
  • how to use monitoring to gain feedback on the impact on blood glucose levels of new activities, eg food, physical activity, hormonal changes, illness.

6. How often is enough?

It has been suggested that people with Type 2 diabetes tend to have more stable glycated haemoglobin than those with Type 1 diabetes and do not require monitoring as frequently (7). This is a generalisation and day-to-day blood glucose levels will still fluctuate. Circumstances in which more frequent testing will need to be considered include:

  • Suspected or confirmed unawareness of hypoglycaemia (18).
  • Regular and/or disabling hypoglycaemia (19).
  • Intensifying or changing treatment regimes to improve glycaemic control (17,20,21)
  • Driving if treated with insulin or oral hypoglycaemic agents meeting DVLA regulations (22,23)
  • Intercurrent illness and then taking the appropriate action (24)
  • Regular and/or intensive physical activity such as swimming, scuba diving, gardening (25)
  • Optimising glycaemic control prior to conception and during pregnancy (26,27,28 [including gestational diabetes 24]).
  • Those using pump therapy or multiple daily intensive insulin therapy (MDI) (24,29).
  • Shift work/ jobs that require proactive self-management, particularly to avoid hypoglycaemia.
  • Those living alone who may be at increased risk of falls.

Healthcare professionals are encouraged to work in partnership with people with diabetes to discuss and agree frequency of testing according to individual needs and circumstances.

7. Further research

Further research is in progress to inform practice about the effectiveness of self-monitoring and identify patients who might derive most benefit from different forms of blood glucose monitoring.

  • A randomised controlled trial to determine the effect of blood glucose self-monitoring in people with type 2 diabetes (DiGEM) : Health Technology Assessment (HTA) Project: Dr Andrew Farmer, Department of Primary Health Care, University of Oxford. To report 2008.
  • Does self monitoring of blood glucose as opposed to urinalysis provide additional benefit to newly diagnosed individuals with Type 2 diabetes receiving structured education? : Diabetes UK grant awarded 2006. Dr Marian Carey et.al . Diabetes Research Team, Leicester. To report in 2008.
  • Efficacy of self-monitoring of blood glucose in type 2 diabetes (ESMON) Project. Research & Development Office, Belfast. Mrs Margaret Copeland, diabetes health care teams from Altnagelvin Area Hospital, Belfast City hospital, Causeway Hospital and the Ulster Hospital. The project commenced in January 2002 and will report in 2006.

These guidelines will be reviewed and updated when further evidence is available.

8. Guidelines for self monitoring of blood glucose

The frequency of testing should be agreed between the person with diabetes and their diabetes care team.

Treatment Group: Type 1 diabetes
– Conventional therapy
– or intensive treatment using 4 or more injections a day (multiple daily injections)

Monitoring regime
Self-monitoring blood glucose (SMBG) should be regarded as an integral part of treatment for all those with Type 1 diabetes. Education should be provided to enable self-monitoring of blood glucose levels and adjustment of treatment and activities appropriately (eg food, physical activity, stress) to avoid/treat hypoglycaemia, control hyperglycaemia, and support stable blood glucose management.

  • Those using conventional insulin therapy (up to two times daily) should be educated to undertake SMBG at least twice daily, varying the time between fasting, premeal and postmeal, to identify trends.
  • As a general rule, the more intensive the therapy the more blood glucose tests may needed, but this should be agreed between the person with diabetes and their diabetes team. However, there is no need to monitor excessively.
  • The majority of people with Type 1 diabetes should consider monitoring their blood glucose levels between 2-4 times daily depending on their treatment, lifestyle and individual needs.
  • Those who alter insulin doses at mealtimes should be encouraged to monitor at least four times daily.
  • More frequent self monitoring during illness is recommended and testing should be done at least four times a day.

Treatment Group: Type 1 diabetes
– Insulin Pump therapy (CSII)

Monitoring regime

  • It is recommended that those using insulin pump therapy should monitor their blood glucose levels between 4-6 times daily.
  • More frequent monitoring will be required during establishment of therapy.
  • More frequent self monitoring during illness is recommended.

Treatment Group: Pre-pregnancy and pregnancy
– Women with pre-existing Type 1 or 2 diabetes
– Gestational diabetes

Monitoring regime

  • Blood glucose monitoring is recommended, between 4 and 6 times a day should be encouraged, to inform treatment changes, activity and food levels and achieve tighter diabetic control, to avoid complications during pregnancy.
  • It is recommended that those with gestational diabetes carry out intensive SMBG. The frequency should be discussed and agreed with the person with diabetes, the diabetes and midwifery teams.

Treatment Group: Type 2 diabetes
– Insulin therapy (Basal Bolus or Twice Daily)

Monitoring regime

  • People who adopt intensive insulin therapies require regular feedback regarding self blood glucose monitoring.
  • People with Type 2 who follow a multiple daily insulin regime should self monitor their blood glucose levels in the same way as those with Type 1 diabetes up to four times daily.
  • People with Type 2 diabetes on twice daily insulin therapy should be supported to test once or twice daily varying the time between fasting, premeal and postmeal, to identify trends.
  • Fasting blood glucose should be tested daily during basal insulin dose titrations.
  • Those with unstable glycated haemoglobin or SMBG levels should be encouraged to test more frequently to inform treatment decisions.

Treatment Group: Type 2 diabetes
– Combined insulin and hypoglycaemic agents

Monitoring regime

  • Fasting blood glucose should be tested once daily during basal insulin dose titration.
  • People with diabetes who use insulin and oral hypoglycaemic agents should be encouraged to self monitor at least once daily, varying the time between fasting, premeal and postmeal, to identify trends.
  • People with diabetes showing that they use blood testing to inform their lifestyle activities should be able to choose to self-monitor as a means of monitoring lifestyle changes, based on their diabetes control.

Treatment Group: Type 2 diabetes
– Healthy eating and physical activity with or without additional metformin +/-  glitazone

Monitoring regime

  • Glycaemic control is best monitored through regular HbA1c testing based on NICE guidelines (15):
    - 6 monthly if stable
    - 2 to 3 monthly if unstable and/or changing treatment.
  • If 2 to 6 monthly HbA1c testing is not accessible locally, SMBG once or twice weekly at different times should be used to inform if deterioration of control is occurring, if this is the method of monitoring preferred by the person with diabetes.
  • If HbA1c is suboptimal, monitoring should be used to identify problems and inform treatment, particularly prior to reviews as appropriate.
  • People with diabetes who prefer to monitor their blood glucose to proactively review and inform lifestyle changes should be able to do so.

Treatment Group: Type 2 diabetes
– Sulphonylureas alone or in combination with other oral antidiabetic agents

Monitoring regime
  • SMBG should be used to reveal if hypoglycaemia is being experienced by those using sulphonylureas or combination therapy.
  • Initial regular testing (1 or 2 times daily) is recommended during titration of dose.
  • More frequent testing (up to 4 times daily) may be necessary when ill.
  • Testing during physical activity or during changes to routine, as necessary, may be beneficial.
  • SMBG prior to a review if HbA1c is suboptimal to identify any problems and inform treatment changes as appropriate.

Acknowledgements

Special thanks to Barbara Elster, Margaret Hunter, Renata Drinkwater, Dora Stelfox, James Walker, Richard Holt, Sharon Martin, June James, Krystyna Matyka, Helen Husband, Rosie Walker, Rudy Bilous and Irene Gummerson for their expertise, advice and contributions to the development of these guidelines.

December 2006

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