Blood Glucose Testing
Self-monitoring of blood glucose (SMBG) is an important element in adjusting or adding new interventions and, in particular, in titrating insulin doses. 1
Structured self monitoring of Blood Glucose (SMBG) enables the visualization of glycaemic levels and allows people with diabetes to obtain and use information about real-time glucose levels. The intention of SMBG is a timely intervention to achieve and maintain near-normal glycemia and to provide feedback to people with diabetes. Intended outcome of SMBG is to enable the individual to more safely manage their condition, detect hyperglycemia and hypoglycemia and to generate information for adjusting medication dosages, the dietary regimen and the physical activity.2
There are many studies which support Self Monitoring of Blood Glucose in Type 1 and Type 2 diabetes. One such study is the ROSSO Study (Retrospective Study "Self-monitoring of Blood Glucose"(SMBG) and Outcome in People with Type 2 Diabetes).
The Inferences of ROSSO Study are:
- It reported nonfatal micro- and macro vascular event rates to be lower in Type 2 diabetic patients who performed SMBG to those who did not perform SMBG (7.2% vs 10.4%)
- The ROSSO Study reported a reduction in morbidity and mortality in diabetic patients who performed SMBG as compared to those who did not perform SMBG.
- SMBG has shown to be able to predict severe hypoglycemia, providing a potential tool to trigger self-regulatory prevention of significant hypoglycemia.
In patients with Type 2 diabetes, SMBG can heighten patients' awareness of the disease and of the impact of lifestyle on blood glucose.
According to DCCT (Diabetes Control and Complications Trial), a rise of 18 mg/dl in mean blood glucose was associated with an 11% rise in cardiovascular risk.
The International Diabetes Federation (IDF) has come out with a latest Guideline "Self-Monitoring of Blood Glucose in Non-Insulin Treated Type 2 Diabetes" recently which mentions:
Effective use of SMBG has several potential benefits in both diabetes education and treatment. SMBG provides:
- support to enhance a diabetes care program that aims to educate people about their condition,
- an instrument for objective feedback on the impact of daily lifestyle habits, special situations (illness, stress) and medication on glucose levels, and thereby to foster self-management and empower the individual to make the necessary changes, and
- Support to the healthcare team in providing individually tailored advice about lifestyle components and blood glucose-lowering medication.
SMBG can serve a dual purpose to enhance diabetes education/understanding and provide a tool for glycaemic assessment. Through this, SMBG use can promote self-confidence and facilitate the necessary behavioural changes and optimization of therapy and its consequent positive outcomes.
SMBG Recommendations as per IDF-2009
- SMBG should be used only when individuals with diabetes (and/or their care-givers) and/or their healthcare providers have the knowledge, skills and will-ingness to incorporate SMBG monitoring and therapy adjustment into their diabetes care plan in order to attain agreed treatment goals.
- SMBG should be considered at the time of diagnosis to enhance the under-standing of diabetes as part of individuals' education and to facilitate timely treatment initiation and titration optimization.
- SMBG should also be considered as part of ongoing diabetes self-management education to assist people with diabetes to better understand their disease and provide a means to actively and effectively participate in its control and treatment, modifying behavioral and pharmacological interventions as needed, in consultation with their healthcare provider.
- SMBG protocols (intensity and frequency) should be individualized to address each individual's specific educational/behavioural/clinical requirements (to identify/prevent/manage acute hyper- and hypoglycemia) and provider requirements for data on glycemia patterns and to monitor impact of thera-peutic decision making.
- The purpose(s) of performing SMBG and using SMBG data should be agreed between the person with diabetes and the healthcare provider. These agreed-upon purposes/goals and actual review of SMBG data should be documented.
- SMBG use requires an easy procedure for patients to regularly monitor the performance and accuracy of their glucose meter.
Recommended Targets as per evidence available from various Associations:
- Pre-Prandial Blood Glucose:
Pre-Prandial Target of 108 mg/dl is recommended for the majority of patients
A less stringent target of 90-126 mg/dl may be recommended in patients with known CAD or risk of severe hypoglycemia.
- Post Prandial Blood Glucose:
Post prandial blood glucose testing of 140 mg/dl taken 2 hrs after a meal is an ideal target and time-point in most, but not all, people with Type 1 and Type 2 diabetes. However, this should be achieved within the limits of maximal safety in order to avoid hypoglycemia.
In pregnant women, 1-hr postprandial blood glucose of 140 mg/dl and 2-hr post prandial blood glucose of 120 mg/dl is recommended.