microvascular complications (P=.0099) and a 16% risk reduction for myocardial infarction (P=.05) compared to conventional therapy. 8 Analysis of these

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1 CONCISE REVIEW ASSESSING FOR GLYCEMIC CLINICIANS CONTROL Assessing Glycemic Control With Self-monitoring of Blood Glucose and Hemoglobin A 1c Measurements GEORGE DAILEY, MD Hemoglobin A 1c ( ) is the gold standard for monitoring glycemic control and serves as a surrogate for diabetes-related complications. Although measures mean glycemic exposure during the preceding 2 to 3 months, it does not provide information about day-to-day changes in glucose levels. Self-monitoring of blood glucose represents an important adjunct to because it can distinguish among fasting, preprandial, and postprandial hyperglycemia; detect glycemic excursions; identify hypoglycemia; and provide immediate feedback to patients about the effect of food choices, activity, and medication on glycemic control. Mayo Clin Proc. 2007;82(2): ADA = American Diabetes Association; 1,5-AG = 1,5-anhydroglucitol; CGM = continuous glucose monitoring; DCCT = Diabetes Control and Complications Trial; = hemoglobin A 1c ; IGT = impaired glucose tolerance; NGSP = National Glycohemoglobin Standardization Program; PPG = postprandial plasma glucose; SMBG = self-monitoring of blood glucose From the Division of Diabetes and Endocrinology, Scripps Clinic and Research Foundation, La Jolla, Calif. A question-and-answer section appears at the end of this article. Individual reprints of this article are not available. Address correspondence to George Dailey, MD, Division of Diabetes and Endocrinology, Scripps Clinic and Research Foundation, N Torrey Pines Rd, La Jolla, CA ( dailey.george@scrippshealth.org) Mayo Foundation for Medical Education and Research The incidence of both type 1 and type 2 diabetes mellitus is increasing; the former has been attributed to an increase in environmental factors, 1 whereas the latter is strongly associated with increasing rates of obesity. 2 Alarmingly, during the past 10 years, type 2 diabetes has been diagnosed more frequently in patients younger than 44 years. 3 In this context, physicians face a dual challenge: not only are there more patients with diabetes, but also the disease is being increasingly diagnosed in younger patients who will require lifelong management. Adding to this burden is the increasing complexity of caring for patients with type 1 diabetes and the expanding armamentarium of medications for patients with type 2 diabetes. The association between diabetes and microvascular and macrovascular complications is well known, as is the need to maintain tight glycemic control to prevent these sequelae. More elusive is the optimal approach to achieving and maintaining target glycemic levels. Despite improved knowledge and a variety of medications, approximately half of the patients with diabetes in the National Health and Nutrition Examination Survey cohort did not meet the American Diabetes Association (ADA) target for glycemic control of a hemoglobin A 1c ( ) level lower than 7.0%. 4 Although improved glycemic control has been successfully attained in numerous clinical trials, it is difficult to achieve or maintain target levels in everyday clinical practice. This point is exemplified in the observational follow-up of patients from the intensive therapy group of the Diabetes Control and Complications Trial (DCCT). In the Epidemiology of Diabetes Interventions and Complications study, the intensive therapy cohort from the DCCT began with a mean level of 7.3%, but after 5 years of care outside the strict protocol of the randomized trial, the levels had deteriorated to a mean of 8.1%. 5 Since publication of the DCCT results, measurements have been considered the gold standard of diabetes care. 6,7 The ADA recommends measuring at least 2 times per year in patients who have met their treatment goals and quarterly in those in whom therapy has changed or who are not meeting their glycemic targets. 7 The level measures glycemic control during the preceding 2 to 3 months, but it does not provide information about day-today glucose levels, nor does it provide immediate feedback to patients about medication or lifestyle choices. For these reasons, self-monitoring of blood glucose (SMBG) levels is considered an important adjunct to measurements for achieving and maintaining glycemic control and consequently for reducing diabetes-related complications. 7 This article discusses the benefits and limitations of and SMBG measurements, as well as the optimal use of SMBG as an adjunct to. HBA 1c AS A MEASURE OF GLYCEMIC CONTROL Numerous studies have shown that elevated is associated with an increased risk of complications in patients with type 1 and type 2 diabetes mellitus and that lowering reduces such risk. In the DCCT, reductions in were accompanied by proportional reductions in the risk of complications, with clinically meaningful risk reductions observed even when was reduced toward the normal range of less than 6%. Similar findings were observed in patients with newly diagnosed type 2 diabetes in the United Kingdom Prospective Diabetes Study, in which intensive blood glucose control yielded a 25% reduction in the risk of Mayo Clin Proc. February 2007;82(2):

2 microvascular complications (P=.0099) and a 16% risk reduction for myocardial infarction (P=.05) compared to conventional therapy. 8 Analysis of these data in terms of levels revealed a continuous relationship between and the risk of complications, with each 1% decrease in resulting in statistically significant reductions of 37% for microvascular complications and 14% for myocardial infarction (P<.0001). 9 These findings are similar to those derived from the DCCT and indicate that the much larger number of patients with type 2 diabetes benefit from glucose lowering to the same degree as those with type 1 diabetes. Thus, serves as a surrogate for the risk of microvascular and macrovascular complications, and these results firmly establish as a useful measure of longterm glycemic control. LIMITATIONS OF MONITORING GLYCEMIC CONTROL USING ONLY HBA 1c HBA DOES NOT PROVIDE INFORMATION ABOUT GLYCEMIC VARIABILITY As an integrated measure of fasting, preprandial, and postprandial glucose levels, may not completely represent the risks that patients with diabetes are exposed to on a daily basis. Although it provides a quantitative measure of mean glucose exposure over an extended period, alone does not indicate the degree of glycemic variability (the frequency and magnitude of glucose excursions) that a patient may experience during a given day (Figure 1). The potential importance of glycemic variability is suggested by findings from the DCCT. Even at equivalent levels, patients receiving intensive therapy (involving more frequent preprandial insulin injections) had a reduction in the risk of progression of retinopathy over time compared with patients receiving conventional treatment. 13 The DCCT research group speculated that complications might be highly dependent on the extent of postprandial glycemic excursions and that conventionally treated patients were more likely to be exposed to greater glycemic excursions than those in the intensive treatment group. 13 A more thorough discussion of this hypothesis, including a mechanism involving hyperglycemia-induced overproduction of reactive oxygen species, was recently published. 14 HBA DOES NOT DIFFERENTIATE AMONG FASTING, PREPRANDIAL, AND POSTPRANDIAL GLYCEMIA Optimal diabetes management involves control of fasting, preprandial, and postprandial glucose levels. However, because represents mean glycemic exposure over time, 15 it cannot be used to identify whether a given patient s abnormal glycemic levels are primarily due to high fasting plasma glucose levels or high postprandial plasma glucose (PPG) levels. Simply put, an elevated measurement signals a need for a change in therapy, but it cannot indicate what type of change is necessary. In fact, the relative contributions of fasting plasma glucose and PPG to vary according to level, with PPG becoming increasingly important as decreases toward target levels. 16 A considerable body of evidence points to the clinical importance of postprandial hyperglycemia, typically evaluated in clinical studies as postchallenge glucose levels in an oral glucose tolerance test. Although the terms postchallenge and postprandial are not synonymous because of the inherent differences between ingesting a pure glucose solution and eating a mixed meal, postchallenge hyperglycemia is often regarded as a surrogate for postprandial hyperglycemia. 17,18 Even when and fasting glucose levels are within the normal range, postchallenge hyperglycemia has been associated with a 2-fold increase in the risk of death from cardiovascular disease. 19 In the Funagata Diabetes Study, impaired glucose tolerance (IGT), defined as a 2- hour postchallenge plasma glucose level between 140 and 198 mg/dl ( mmol/l), as opposed to impaired fasting glucose (defined in that study as mg/dl [ mmol/l]) was shown to double the risk of death from cardiovascular disease. 20 The increased risk of macrovascular disease among patients with IGT but not impaired fasting glucose, combined with the greater contribution of postprandial hyperglycemia to overall glycemia when levels are lower, may help to explain why even newly diagnosed patients have an increased cardiovascular risk. When IGT progresses to diabetes, the patient has been exposed to postprandial glycemic excursions for many years. In the Diabetes Intervention Study, elevated PPG levels after a normal breakfast were associated with significantly higher mortality during an 11-year follow-up of patients with newly diagnosed type 2 diabetes (P<.01). 21 In support of these findings, prospective interventions that control PPG have been shown to improve endothelial function and reduce carotid atherosclerosis in patients with type 2 diabetes. 22 Postprandial hyperglycemia was recently linked to microvascular complications as well. In a study of 151 Japanese patients, PPG levels correlated better than measurements with the risk of retinopathy progression. 23 INACCURACIES IN HBA TEST RESULTS More than 30 different assays are currently available. Differences among these assays as well as variations between and within laboratories can affect results. In 1996, the National Glycohemoglobin Standardization 230 Mayo Clin Proc. February 2007;82(2):

3 Glucose concentration (mmol/l) Glucose concentration (mg/dl) Meter value Sensor value Insulin Meal Exercise Other :00 AM 4:00 AM 8:00 AM 12:00 PM 4:00 PM 8:00 PM 12:00 AM Time Meter value Sensor value Insulin Meal Exercise Other :00 AM 4:00 AM 8:00 AM 12:00 PM 4:00 PM 8:00 PM 12:00 AM Time FIGURE 1. Top, Glucose profiles derived from continuous glucose monitoring reveal glycemic variability in a patient with type 1 diabetes. Reprinted from Bode et al. 11 Copyright 1999 with permission from Elsevier. Bottom, Glucose profiles derived from continuous glucose monitoring reveal glycemic variability in a patient with type 2 diabetes. From Hay et al 12 with permission. Program (NGSP) was established in the United States to certify assay methods as traceable to DCCT reference values. 6 Certification from the NGSP requires an assay method s reference interval to be within 5% of the normal level of 4% to 6%, with variations limited to less than 3% within a laboratory and less than 5% between laboratories. 6 The ADA now recommends that laboratories use only NGSP-certified assays. 6 Some medical conditions may cause inaccurate test results. 6 Conditions or factors that shorten red blood cell life span, such as acute blood loss, hemolytic anemia, and some medications used for human immunodeficiency virus positive patients, 24 will yield falsely low values regardless of assay method. Hemoglobin variants, hemoglobinopathies, conditions that result in increased erythrocyte turnover, and blood transfusions can increase or decrease levels depending on the condition and the assay method used. 25 Iron deficiency anemia, hypertriglyceridemia, hyperbilirubinemia, uremia, and high doses of acetylsalicylic acid can produce falsely high measurements. 26 Dietary supplements and opiate or alcohol abuse can also affect results. 26 Vitamins C and E may lower test results by inhibiting glycation of hemoglobin, and vitamin C has also Mayo Clin Proc. February 2007;82(2):

4 been reported to increase values, depending on the assay used. 6 POTENTIAL ALTERNATIVES TO HBA Two other analytes, fructosamine and 1,5-anhydroglucitol (1,5-AG), have been evaluated as intermediate markers of glycemia. The fructosamine assay measures glycation of serum proteins, principally albumin, that have a shorter half-life than hemoglobin. 49 Thus, fructosamine provides an index of glycemia over a shorter period (approximately 2 weeks) compared to measurements. 25 The accuracy and clinical utility of fructosamine have been questioned because of interference from various substances. 25,49 The 1,5-AG assay measures serum levels of a compound that competes with glucose for reabsorption at the renal tubule and was recently approved by the US Food and Drug Administration. 25 In use in Japan for more than a decade, 1,5-AG levels appear to be less sensitive to small changes in glycemic control at high levels. It cannot identify hypoglycemia, and results are influenced by impaired renal function. 50 Future studies may support the use of 1,5-AG as a means to detect postprandial glycemic excursions. USING SMBG TO COMPLEMENT HBA Self-monitoring of blood glucose provides a real-time measure of blood glucose levels and consequently represents a valuable adjunct to the periodic determination of values. 27,28 Accordingly, SMBG provides patients with instant feedback about the effects of food choices, exercise, stress, and medications on their glycemic levels. Although the optimal frequency and timing of SMBG depend on many variables including diabetes type, level of glycemic control, management strategy, and individual patient factors, SMBG allows clinicians to fine-tune therapy and thus more effectively manage their patients glucose levels. When used properly, most modern glucose meters demonstrate a high degree of clinical accuracy compared with laboratory instruments, 29,30 and average SMBG readings generally correlate well with values. 31 The relationship between mean blood glucose and levels has been the subject of recent debate, and new data from continuous glucose monitoring (CGM) may lead to modifications of conversion tables for mean blood glucose and. 32 SMBG CAN IDENTIFY HYPOGLYCEMIC EPISODES Fear of hypoglycemia often leads to a less intensive management approach by clinicians and patients, resulting in suboptimal glycemic control. Hypoglycemia is a concern to patients with type 1 diabetes and those with type 2 diabetes managed with insulin or oral agents. In a study using CGM in elderly patients with type 2 diabetes, no patients reported symptoms of hypoglycemia, yet 80% had glucose values lower than 50 mg/dl (2.8 mmol/l) on at least 1 occasion. 12 Self-monitoring of blood glucose provides a means of identifying daily hypoglycemic events, allowing immediate treatment and modification of therapeutic regimens to allow tighter glycemic control while minimizing future hypoglycemic risk. SMBG DETECTS GLYCEMIC EXCURSIONS Continuous glucose monitoring studies show that daily blood glucose values range widely in both hypoglycemic and hyperglycemic ranges. 12,33 Although real-time CGM devices that measure glucose concentrations in interstitial fluid have recently entered the market, they are indicated as adjuncts to standard SMBG, and all therapy adjustments should be based on measurements obtained from a blood glucose meter. Both SMBG and CGM have the ability to identify glycemic excursions. In a study of 600 insulintreated patients, regular SMBG an average of 3 times per day for 3 months revealed a wide range of daily glucose values. 34 When mean minimal and maximal values were determined, blood glucose ranged from 40 to 449 mg/dl in patients with type 1 diabetes and 63 to 382 mg/dl in patients with type 2. The wide variation in glucose levels, particularly the dangerously low values observed in the patients with diabetes, would not have been detected by alone. For patients treated with insulin, an occasional SMBG reading in the middle of the night can help detect nocturnal hypoglycemia. It is important to recognize that postprandial glucose excursions may still be present in patients who have achieved their target. A study of patients with type 2 diabetes who performed SMBG before and 2 hours after meals showed that many with levels lower than 7.0% had postprandial glucose levels in excess of 160 mg/ dl and glucose excursions of more than 40 mg/dl. 10 In a cross-sectional analysis of the Third National Health and Nutrition Examination Survey cohort, postchallenge hyperglycemia was identified in 39% of patients with type 2 diabetes who were not using insulin and had an level lower than 7.0%. 35 Diabetes management software, with data uploaded from blood glucose meters, can be used to calculate the SDs of blood glucose values. Analyzing SDs is perhaps the simplest method to identify the degree of glycemic fluctuations ACCUMULATING EVIDENCE FOR IMPROVED GLYCEMIC CONTROL IN TYPE 2 DIABETES The use of SMBG to detect hypoglycemia and hyperglycemia and then adjusting therapy to minimize glycemic excursions is generally considered standard practice in type 1 diabetes. In patients with type 2 diabetes, especially those 232 Mayo Clin Proc. February 2007;82(2):

5 not taking insulin, SMBG use has been more controversial. The observational Fremantle Diabetes Study, which reported cross-sectional and longitudinal data, found no significant benefit associated with SMBG. 39 Likewise, a small study by Davidson et al 40 found no statistically significant improvements in for patients randomized to SMBG vs controls. Cross-sectional SMBG studies 39,41,42 are incapable of demonstrating a cause-and-effect relationship between SMBG and because the data do not evaluate changes in over time in the presence of an intervention. 43 In the longitudinal arm of the Fremantle Diabetes Study, the mean SMBG testing frequency of less than 1 test per day in patients treated with diet or oral agents or less than 2 tests per day in insulin-treated patients may have been suboptimal for providing actionable feedback to patients. Additionally, the study did not clearly indicate how SMBG was integrated into the diabetes management plan or whether patients were taught how to respond to out-oftarget blood glucose readings. Similarly, the study by Davidson et al 40 did not clearly report how SMBG results were used by patients or their health care professionals. The sample size, wide 95% confidence interval, less than 40% adherence to recommended SMBG frequency, and poorly educated study population may have contributed to the failure to achieve a significant difference. Recently, however, 2 meta-analyses demonstrated that including SMBG as part of a multicomponent management strategy results in a statistically significant decrease in of approximately 0.40% in patients with type 2 diabetes who are not taking insulin. 44,45 When extrapolated to findings from the United Kingdom Prospective Diabetes Study, this decrease would be expected to reduce the risk of microvascular complications by approximately 14%. 45 A 4- year longitudinal study that differentiated new users of SMBG from experienced users found a proportional relationship between SMBG frequency and reduction regardless of therapy for new users and a similar association among pharmacologically treated experienced users. 46 Finally, a large epidemiological study of patients with type 2 diabetes that spanned 6.5 years showed that SMBG was associated with lower diabetes-related morbidity and all-cause mortality, even among patients not receiving insulin. 47 Hence, a growing body of evidence suggests that daily SMBG has clinical value in type 2 and type 1 diabetes. LIMITATIONS OF SMBG Effective SMBG requires that patients be trained in how to use their blood glucose meters, understand when testing should be done and what the test results mean, and recognize when action needs to be taken. Unlike measurements, SMBG is episodic: it measures glucose at 1 point in time. Accordingly, SMBG timing is important, and the date and time must be set correctly on the meter to enable proper interpretation of the results. It is important that the clinician and the patient agree on glucose targets and how to achieve them having the patient s input on targets encourages better self-management. 48 Most importantly, SMBG may not significantly improve glycemic control unless steps are taken to act on the results. OPTIMAL USE OF SMBG ESTABLISHING A GLUCOSE PROFILE To take full advantage of the benefits of SMBG, patients must collect data at appropriate times during the day, recognize readings that are outside their target range, and take action to improve their glycemic control. This is most easily accomplished by having patients compile a periodic glucose profile by taking a series of blood glucose measurements throughout the day, capturing information from the fasting, postprandial, and postabsorptive (or late postprandial) periods. Conversely, by staggering SMBG measurements at different times on different days, patients can generate an accurate portrait of day-to-day glycemic excursions while avoiding the need to test many times in a single day. Regardless of the testing regimen, patients should be encouraged to collect data on glucose levels relative to meals. Studies that have used meal-based SMBG testing have demonstrated improvements in. 51,52 The ability to download memory meters with a date and time stamp greatly facilitates this process. Some meters have event markers for meal times, insulin doses, exercise, and hypoglycemia, substantially adding to the power of the analysis. PATTERN RECOGNITION Regardless of the monitoring regimen, a key to effective use of SMBG in clinical practice is pattern management, a systematic approach to recognizing the glycemic patterns within SMBG data and then taking action based on those results. This approach consists of several key steps 53 : (1) establish both premeal and postmeal blood glucose targets; (2) gather data on blood glucose levels, carbohydrate intake, insulin dose (when applicable), activity levels, schedule, and physical and emotional stress; (3) analyze data to determine whether any patterns emerge; (4) assess any influencing factors; (5) take action; and (6) regularly monitor blood glucose levels to evaluate the impact of actions taken. By using the data gathered during a specified period, the clinician and patient can review patterns of glycemic excursions and then make adjustments to meals, activities, and medications to better control glucose levels, minimize glycemic excursions, and limit hypoglycemia. Mayo Clin Proc. February 2007;82(2):

6 TABLE 1. Self-monitoring Blood Glucose Profile of a Representative Patient With Type 2 Diabetes* Blood glucose, mg/dl (mmol/l) Breakfast Lunch Dinner Day 2:00 AM 7:00 AM 9:00 AM NOON 2:00 PM 6:00 PM 8:00 PM 11:00 PM Comments Monday 90 (5.0) 128 (7.1) 193 (10.7) 178 (9.9) 220 (12.2) Tuesday 92 (5.1) 140 (7.8) 220 (12.2) 187 (10.4) 233 (12.9) 210 (11.7) Burrito for lunch Wednesday Thursday 117 (6.5) 202 (11.2) Fast food burger and soft drink for lunch Friday 86 (4.8) 130 (7.2) Saturday 207 (11.5) 262 (14.5) Enchiladas for dinner Sunday 207 (11.5) Monday Tuesday 205 (11.4) Wednesday 156 (8.7) 228 (12.6) 205 (11.4) 190 (10.5) Ham sandwich for lunch Thursday Friday 92 (5.1) 134 (7.4) Saturday Sunday 104 (5.8) 206 (11.4) 184 (10.2) Pancake for breakfast *Patient was asked to construct a glucose profile using a staggered approach by testing before and after different meals on different days. ILLUSTRATIVE CASE Mr G is a 53-year-old man with hypertension and dyslipidemia that are controlled with oral drug therapy. He has a family history of cardiovascular disease. When diabetes was diagnosed 2 years ago, Mr G had an level of 7.5%. After 6 months of nutritional therapy, his level remained higher than 7.0%, and metformin was prescribed. Although his level initially declined to 6.7%, it gradually returned to the original level of 7.5% during the course of a year. Self-monitoring of blood glucose was used to create a glucose profile that showed fasting glucose levels in the range of 90 to 130 mg/dl but frequent postprandial glucose excursions higher than 200 mg/dl (Table 1). On the basis of this SMBG pattern, preprandial repaglinide was prescribed, and Mr G was told to perform SMBG regularly during the next few weeks to detect impending hypoglycemia and to monitor his response to the change in therapy. At his last visit, Mr G s level had improved to 6.9%. This case illustrates how SMBG can be used to tailor treatment to improve glycemic control. Adding repaglinide to target postprandial hyperglycemia improved Mr G s overall glycemic profile and possibly reduced his cardiovascular risk. Alternatively, a rapid-acting insulin could be prescribed in many such patients. SUMMARY Hemoglobin A 1c is considered the gold standard for monitoring long-term glycemic control in diabetes, but for optimal management it should be complemented with the dayto-day information provided by SMBG. Beyond signaling a need to change or adjust therapy, SMBG can identify the specific glycemic abnormality that should be addressed. Taking full advantage of SMBG requires that patients regularly monitor their blood glucose levels before and after meals and then discuss the results with their physician. Patients with type 2 diabetes, especially those not taking insulin, may not fully understand the benefits of SMBG and may be reluctant to perform frequent monitoring. Such patients may better appreciate the benefits of SMBG by first constructing a glucose profile. Self-monitoring of blood glucose may reveal which aspects of glycemic control are most problematic for the patient fasting, preprandial, or postprandial. This information can then be used to make appropriate adjustments to diet, activities, and medication. Glycemic excursions are common, even among patients with well-controlled diabetes. They can be readily identified by regular SMBG testing before and after meals and by periodic glucose profiling. Using SMBG as an adjunct to is a sensible approach to diabetes management and can help to improve glycemic control in both type 1 and type 2 diabetes. REFERENCES 1. EURODIAB ACE Study Group. Variation and trends in incidence of childhood diabetes in Europe [published correction appears in Lancet. 2000;356:1690]. Lancet. 2000;355: International Diabetes Federation. Diabetes Atlas. 2nd ed. Brussels, Belgium: International Diabetes Federation; Koro CE, Bowlin SJ, Bourgeois N, Fedder DO. Glycemic control from 1988 to 2000 among U.S. adults diagnosed with type 2 diabetes: a preliminary report. Diabetes Care. 2004;27: Resnick HE, Foster GL, Bardsley J, Ratner RE. Achievement of American Diabetes Association clinical practice recommendations among U.S. adults with diabetes, : the National Health and Nutrition Examination Survey. Diabetes Care. 2006;29: Writing Team for the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Research Group. Effect of intensive therapy on the microvascular complications of type 1 diabetes mellitus. JAMA. 2002;287: Mayo Clin Proc. February 2007;82(2):

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8 Questions About Assessing Glycemic Control With and SMBG 1. Which one of the following is not a limitation of using alone as a measure of glycemic control? a. Hemoglobin A 1c does not reflect glycemic variability b. Hemoglobin A 1c does not indicate whether hyperglycemia is mainly due to fasting, preprandial, or postprandial glucose levels c. Hemoglobin A 1c does not serve as a surrogate for risk of microvascular and macrovascular complications d. Hemoglobin A 1c cannot warn of impending hypoglycemia e. Hemoglobin A 1c cannot provide real-time patient feedback on the effects of diet, exercise, illness, stress, or medications 2. Which one of the following statements is false? a. Hemoglobin A 1c reflects mean glycemic exposure during the preceding 2 to 3 months b. Unlike SMBG, results are independent of conditions that increase erythrocyte turnover c. Risk of complications is reduced as is reduced, even below 6.5% d. The terms postchallenge and postprandial are not interchangeable because of the differences between consuming a glucose solution vs a mixed meal e. Unlike, the timing of SMBG testing is important 3. Which one of the following is not an important consideration in maximizing the benefit of SMBG? a. Self-monitoring of blood glucose should be performed at about the same time every day b. Clinicians and patients should agree on glucose targets and what to do about out-of-target readings c. Patients should be educated on how to use their meters, including how to set the date and time correctly d. Periodic glucose profiles allow patients to recognize patterns of inadequate glycemic control e. Self-monitoring of blood glucose is not a direct intervention, and patients or their clinicians must take action based on the data to reduce levels 4. Which one of the following is not considered a part of pattern recognition? a. The physician should review with the patient the types of foods that should be avoided b. The patient should compile a weekly glucose profile and maintain a food/activity diary c. The patient should circle all out-of-target blood glucose values they have recorded and note the time of day when most of the excursions occur d. The patient should note episodes of illness, stress, and strenuous exercise in the electronic logbook that is a part of the glucose meter e. The patient should be encouraged to take a 20- minute walk when postprandial glucose values are above target 5. Which one of the following statements is true? a. Hemoglobin A 1c is considered the gold standard for monitoring day-to-day glycemic control b. An level above goal may be due to fasting or postprandial hyperglycemia c. Self-monitoring of blood glucose is useful only for patients being treated with insulin or oral agents d. Postprandial glycemic excursions are uncommon in patients with well-controlled diabetes e. Even in the absence of making changes based on the data, the act of performing SMBG at the recommended frequency and timing can improve glycemic control Correct answers: 1. c, 2. b, 3. a, 4. a, 5. b 236 Mayo Clin Proc. February 2007;82(2):