Using Self-Monitoring of Blood Glucose in Noninsulin-Treated Type 2 Diabetes Free

A recent review of guidelines for SMBG in people with type 2 diabetes¹⁶  concluded that, because SMBG interventions cannot be isolated from self-management education, it is unclear whether SMBG itself is effective. The review questioned the validity of numerous guidelines proposing SMBG for patients with type 2 diabetes because these recommendations were not evidence based.

However, SMBG cannot and should not be isolated from DSME/T. Without DSME/T, SMBG would have little if any benefit. Another researcher⁷  has cited the self-regulation model, or common-sense model, of illness as appropriate for using SMBG in patients with diabetes who do not take insulin. This would seem to make sense in that it puts the responsibility for changing behavior and controlling diabetes in the hands of patients, who can then decide whether diet, exercise, or other interventions are necessary to decrease their glucose values and improve their glycemic control. Successful treatment of all self-care behaviors in combination with SMBG requires that practitioners address both individuals' physiological and behavioral control systems that work to regulate blood glucose levels.⁷ 

The literature to date has been inconsistent. However, the International Diabetes Federation noted in its 2008 guidelines on SMBG for noninsulin-treated patients with type 2 diabetes¹⁷  that, “Data available from randomized controlled trials suggest that SMBG is likely to be an effective self-management tool only when results are reviewed and acted upon by healthcare providers and/or people with diabetes to actively modify behavior and/or adjust treatment. SMBG should be used only when individuals with diabetes (and/or their caregivers) and their health care practitioners have the knowledge, skills, and willingness to incorporate SMBG monitoring and therapy adjustment into their diabetes care plan in order to achieve agreed upon treatment goals.”

Sometimes, patients who are referred to diabetes educators or diabetes practitioners have stopped performing glucose tests because, “They are all high … . I get depressed looking at the results … . And what am I supposed to do with the results?” Many do not know what their target ranges should be. In addition, with the advent of memory meters that can be downloaded, many patients arrive at their appointments and have their meter downloaded but may never have actually looked at the results.

Patients often do not understand how to interpret SMBG results or how their eating habits, physical activity, other behaviors, and medications influence their blood glucose levels. When asked why a glucose reading is 250 mg/dl, a patient may respond with, “I don't remember” or “I don't know.”

So, what is the purpose of SMBG in the context of noninsulin-treated type 2 diabetes if patients and/or their health care providers (HCPs) do not know what to do with the data it provides? Out of frustration, some HCPs simply increase patients' medication when their A1C is elevated without trying to determine the reasons behind the high A1C level.

Certainly, asking people to check their glucose levels at home and not looking at their records during office visits sends a message that this task is not important, rendering the glucose records useless. In addition, the costs of SMBG can be prohibitive for some patients. Yet, devising a structured monitoring program for checking glucose levels at specific times of day can yield important information for both patients and HCPs. SMBG schedules can also be tailored based on the types of medications a person may be taking. Thus, SMBG can be an effective tool in patient-centered care, providing HCPs with vital information to help educate patients and manage their disease.⁷ 

Patient assessment is required to develop and implement an effective program for SMBG and DSME/T. Before implementing any medical or behavioral intervention, it is necessary to obtain a comprehensive history on each patient. This is not the same type of comprehensive assessment that is performed in the setting of a medical office visit. Rather it includes details about an individual's lifestyle.

Finding out such things as the time an individual awakens, sleeps, eats, takes medications, and checks glucose is important in designing a treatment program. In addition, information about what people do during the day, what types of activities they enjoy, what their work setting is like, their exercise habits and alcohol intake, and other aspects of their daily life should be considered in devising a treatment plan that includes SMBG. Determining how patients with diabetes think about their diabetes and even whether they are willing to check their glucose may change an HCP's approach to their diabetes management.

Because SMBG requires an understanding of numbers for interpretation of results, assessing patients' numeracy and health literacy is crucial. This includes patients' basic reading skills, ability to understanding and act on health care information, ability to perform calculations and other numerical tasks, and quantitative skills that may be needed to successfully self-manage diabetes.^18,19  Performing patient-centered assessments helps to involve people with diabetes in meaningful discussions about interpreting SMBG results to develop individualized goals and prescribe medications.

The outcome of DSME/T is measurable behavior change. People with diabetes must incorporate knowledge of and skills relating to SMBG to effectively change behavior that is under their control.²⁰  The American Association of Diabetes Educators' AADE7 Self-Care Behaviors system²¹  includes monitoring as one of the essential behaviors in self-management and has identified daily SMBG as an effective tool that provides immediate feedback about the effects of food, physical activity, stress, and medications. Some consider SMBG to be an integral part of a multicomponent system for effective self-regulation of blood glucose.⁷ 

Although not all randomized, controlled trials of SMBG have shown improvement in A1C, some^11,12  have found that patients who changed their self-management behaviors in response to SMBG improved their A1C.

Therefore, an SMBG education program should go beyond the basic how-to skills of performing SMBG to include knowledge and applications regarding appropriate self-care behaviors (the AADE7)²¹  and the encouragement needed for patients to become self-managers of their diabetes. As described by McAndrew et al.,⁷  the components of an SMBG education program should include 1) instruction on how to use a glucose meter; 2) interpretation of SMBG results and identification of target ranges; 3) determination, through problem-solving, of the connection between a blood glucose value and patients' prior behaviors; 4) determination of an action plan based on SMBG results to bring glucose values into the target range; 5) explanation that a particular feeling or symptom may not always indicate that blood glucose is high or low; 6) creation of a regimen that facilitates the integration of SMBG (and other behaviors) into patients' lifestyle; and 7) nonjudgmental evaluation of SMBG results.

Nonjudgmental evaluation is particularly important. HCPs sometimes unwittingly promote the concept of “good” or “bad” blood glucose levels, which may affect how patients think about themselves (e.g., “I am a bad person because my glucose levels are high.”) The value judgments that people place on themselves as a result of unacceptable glucose values can trigger emotional issues.²²  Similarly, the word “test” (as in, “blood glucose test”) can cause anxiety for some people. HCPs can reduce these negative feelings by referring to glucose values using terms such as “in range” or “out of range” instead of “good” or “bad” and by referring to SMBG as “glucose checks” or “glucose measurements” instead of “glucose tests.”²³ 

Having patients keep a diary for a week is helpful when teaching the associations between SMBG results and behaviors. Instructing patients to check their blood glucose in the morning a few times a week may not provide enough information for meaningful education.

One approach HCPs may consider would be to suggest to patients who are just beginning SMBG that they treat the process like a scientific experiment, the goal of which is to discover how their body responds to a variety of factors (e.g., eating more or less food, being psychologically stressed, or getting more or less exercise). Treating SMBG as a data-gathering process can help to remove potential negative judgment; if your goal is to find out how your body responds, then all results are “good” because they expand your knowledge.

Some studies have examined the effects of a variety of structured glucose monitoring schedules on behavior.⁷  In one study,¹²  participants were asked to follow a regimen that involved performing SMBG six times per day (before and 1 or 2 hours after meals) on 2 or 3 days per week that included 1 or 2 weekdays and a week-end day. Participants kept diaries of SMBG results, foods they ate, and feelings of well-being. Participants were taught to use the data they collected, and medical staff used a counseling algorithm to help the participants learn problem solving. The algorithm was a series of six questions focusing on self-perception, self-reflection, and self-regulation.

The results of this study showed that participants who received this training were able to make behavioral changes based on interpretation of their SMBG data to improve metabolic control and lower A1C levels 1.0 ± 1.08% in the intervention group (compared to 0.54 ± 1.41% in the control group, P = 0.0086). Thus, carefully designing an SMBG schedule and teaching people what the results mean and what they can do in response to improve their diabetes control can result in behavioral changes and improvements in metabolic control.³ 

Because many individuals with non-insulin-requiring type 2 diabetes are adults, using the principles of adult learning in patient education programs may facilitate self-motivation and self-management of diabetes. Most adult learners are problem-centered and appreciate being shown how a new skill or knowledge can be applied to their own situation. Most are also results-oriented, self-directed, and somewhat skeptical; thus, they need to try something out before accepting it.²⁴  SMBG education seems to fit well into this framework by showing people with diabetes why and how they need to perform SMBG, explaining what the numbers mean, and then allowing them, with guidance, to experiment with behaviors that affect their glucose levels.

Styles of learning should also be incorporated into SMBG education programs. Graphic displays and pictures appeal to those who prefer visual learning, listening to information appeals to auditory learners, and assignments to record events surrounding blood glucose results can appeal to kinesthetic learners.²⁵  Employing a variety of strategies may help to ensure that the information reaches all participants.

Some people with diabetes believe SMBG is unnecessary because they believe they “can tell” when their glucose is high or low. However, research has shown just the opposite: that patients generally underestimate their blood glucose levels compared to their actual test results.⁷  Many individuals become enlightened when they see SMBG results much higher or lower than they felt their blood glucose level was.

Another “teachable moment” can be brought about by randomly checking patients' capillary blood glucose (CBG) level during an office visit. Frequently, a patient whose CBG result is, for example, 230 mg/dl, will say, “I don't understand! My sugar was 118 mg/dl this morning when I woke up!” Patients will swear that their glucose is never that high when they check it at home, without considering the variations in glucose levels that can occur at different times throughout the day.

Another scenario that sometimes occurs when CBG results are high in the office is for patients to explain that they just finished eating “a few minutes ago,” as if that explains the hyperglycemia. This offers an opportunity to educate people with diabetes about target glucose levels, normal glucose values, and the effects of different foods, and perhaps stress, on glucose levels. Comparing normal glucose fluctuations to their own glucose fluctuations can help people with diabetes visualize when their levels are out of range.

A well-designed SMBG schedule can aid HCPs in selecting and evaluating the effectiveness of diabetes medications.

It is helpful to briefly review the basic pathophysiology of type 2 diabetes because pharmacological agents target different abnormalities related to diabetes.²⁶  Type 2 diabetes is frequently attributed to impaired insulin secretion and insulin resistance in the skeletal muscle tissue, adipose tissue, and liver. Impaired insulin secretion is caused by dysfunction of pancreatic β-cells. Insulin resistance is decreased glucose uptake and clearance in the skeletal muscles and liver and results in increased hepatic glucose production and inability to suppress glucagon.

In the gut, the hormones glucagon-like peptide-1 and glucose inhibitory polypeptide also affect glucose homeostasis. They augment glucose-stimulated insulin secretion by β-cells, facilitate uptake of glucose by muscle tissue and the liver, suppress glucagon secretion by pancreatic α-cells, and slow the rate of gastric emptying.²⁷  People with type 2 diabetes often have a deficiency of or resistance to these hormones, just as they have a deficiency of or resistance to insulin.

Table 1 provides a list of frequently used medications for type 2 diabetes, their specific mechanisms of action, and recommendations for SMBG scheduling to aid in evaluating their effectiveness in specific patients. To effectively and safely initiate and alter medication regimens, HCPs must know whether their patients are experiencing hyperglycemia primarily in the fasting state or postprandially or both. Adequate SMBG data are also necessary to determine whether selected medications have successfully ameliorated the hyperglycemia they were intended to resolve.

All people with type 2 diabetes should be given the opportunity to learn about the value of and skills required to perform SMBG as it applies to their specific needs. Mastering the skills needed to perform and interpret SMBG empowers individuals with diabetes to learn more about their diabetes and to make behavioral changes to improve their overall diabetes control. SMBG also benefits HCPs by providing the blood glucose data necessary to confidently initiate and evaluate medication therapy for patients with diabetes.

SMBG is an important tool and skill set within DSME/T. As with all diabetes self-care activities, the process should begin with an individualized assessment leading to the development of a specific SMBG plan developed and negotiated with patients. Following an appropriately tailored SMBG regimen and sharing their results with their HCPs can greatly help people with diabetes optimize their diabetes treatment to achieve and maintain glycemic control.