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Obtain a fasting plasma glucose level or alternative test to screen for type 2 diabetes mellitus in patients with selected comorbidities or risk factors for the disease.
Counsel all diabetic women of childbearing potential on the need for pregnancy planning.
Counsel all obese women of childbearing age on the need for diet and exercise to decrease the risk of gestational diabetes.
Stop ACE inhibitor therapy, switch oral hypoglycemics to insulin, and review all other medications before conception.
Know that no direct evidence exists showing that screening for type 2 diabetes improves health outcomes or mortality rates.
Screen all adults with CVD, hypertension, dyslipidemia, or other CVD risk factors for diabetes.
Understand that there is insufficient evidence for diabetes screening in adults without CVD risk factors.
Consider screening for diabetes in adults 18 years or older with risk factors for type 2 diabetes (family history, obesity, gestational diabetes, polycystic ovarian syndrome, high-risk ethnic group).
Recognize that although there is no direct evidence about screening intervals, expert panels have recommended screening every 3 years.
Use the FBG test to screen for diabetes because it is easier to administer, is less costly, and is more reproducible than the 75-g OGTT to detect diabetes.
Consider performing a 75-g OGTT in individuals with an FBG of 100 to 126 mg/dL (5.6 to 7.0 mmol/L), as diabetes cannot be adequately confirmed or excluded with FBG values within that range.
Appreciate that the HbA1c test has good specificity but only moderate sensitivity to diagnose diabetes, and it has not yet been standardized for diabetes screening purposes.
Appreciate that intensive glycemic control in persons with type 2 diabetes reduces intermediate markers of microvascular complications, but it has not been convincingly shown to reduce end-organ complications or macrovascular disease.
Be aware that treatment of overweight diabetes patients with metformin reduces CVD events, diabetes-related complications, and mortality rate.
Recognize that treatment of hypertension and dyslipidemia in persons with diabetes reduces the risk of CVD events and mortality to a greater extent than in those without diabetes, partly due to their higher baseline risk for CVD, and because treatment is effective at lower levels of BP and LDL cholesterol in patients with diabetes.
Recognize that ASA treatment reduces cardiovascular events in type 2 diabetes patients with CVD or at high risk for CVD.
Recognize that the natural history of diabetes includes an asymptomatic phase that would be detected only through screening or opportunistic testing and that complications can occur before clinical symptoms of diabetes are apparent.
Recognize that the prevalence of diabetes increases significantly with age.
Know that the risk of type 2 diabetes is significantly increased among patients with a first-degree family member with a history of diabetes.
Know that nearly all minority groups in the U.S. have an increased risk of type 2 diabetes.
Recognize that women with gestational diabetes have a high risk of developing type 2 diabetes, with the highest incidence in the first 5 years after pregnancy.
Recognize that women with polycystic ovarian syndrome have a higher prevalence of type 2 diabetes than women without the syndrome.
Note that the risk of diabetes significantly increases with increasing obesity, with the greatest risk in persons with abdominal fat accumulation.
Note that persons with CVD, hypertension, dyslipidemia, and other features of the metabolic syndrome have an increased incidence of diabetes.
Note that diabetes increases the risk of cardiovascular events, and that men over age 55 and women over age 60 with diabetes have at least a 10% risk of cardiovascular events over 10 years.
Know that a 2-hour PG value of ≥200 mg/dL (11.1 mmol/L) after a 75-g OGTT is considered the gold standard for diagnosing diabetes mellitus.
Recognize that the ADA criterion for diabetes of an FBG of ≥126 mg/dL (7.0 mmol/L) is more reproducible than the 2-hour PG and has excellent specificity for diagnosing diabetes, but its sensitivity is only approximately 50%.
Know that lowering the threshold FBG value increases the sensitivity but decreases the specificity for a diagnosis of diabetes; therefore, although the optimal threshold FBG value to exclude diabetes may be <100 mg/dL (5.6 mmol/L), a 2-hour PG would be required to confirm diabetes in patients with an FBG ≥100 mg/dL (5.6 mmol/L).
Recognize that the HbA1c test has good specificity but only moderate sensitivity for detecting undiagnosed diabetes, and its performance varies depending on the population and cutpoint used.
Recognize that consideration of age, BMI, and race/ethnicity in screening to detect diabetes and pre-diabetes may be less important than evaluation of random plasma glucose.
Know that risk assessment questionnaires developed to screen for diabetes have inadequate sensitivity and specificity in identifying persons with undiagnosed diabetes.
Know that there is limited evidence regarding the harms of screening for diabetes; however, screening tests appear to be safe and have minimal effect on quality of life.
Recognize that although tight glycemic control in persons clinically diagnosed with type 2 diabetes may reduce intermediate markers of diabetes complications, it has not been convincingly shown to lead to significant reductions in end-organ complications or mortality rates.
Note that metformin treatment in overweight patients with newly diagnosed diabetes is associated with reductions in mortality rates, MI, and diabetes complications.
Appreciate that tight BP control in patients with diabetes is associated with reductions in cardiovascular outcomes and deaths and that optimal BP targets differ depending on diabetes status.
Know that treatment of type 2 diabetes patients with microalbuminuria and overt nephropathy using ACE inhibitors and angiotensin-receptor blocking agents reduces the risk of nephropathy progression.
Note that it remains unclear whether hypertensive patients with diabetes without nephropathy should be treated with different antihypertensive agents than those without diabetes.
Recognize that patients with diabetes derive substantial benefit through primary and secondary prevention of cardiovascular events and death with lipid-lowering treatment, even with near-normal baseline lipid levels.
Note that patients with diabetes have similar relative benefits on CVD protection with ASA treatment as those without diabetes, but their absolute benefit may be greater due to their greater baseline risk of CVD.
Recognize that there is no evidence that initiation of foot care programs during the preclinical phase of diabetes provides additional benefit.
Know that there is limited evidence regarding the harms of early treatment in patients with diabetes diagnosed through screening, but the recommended treatments have been shown to be safe in those diagnosed clinically.
Know that there is no direct evidence that screening for diabetes reduces adverse outcomes.
Understand that there is fair evidence that detecting diabetes in persons with CVD, hypertension, dyslipidemia, and other CVD risk factors improves estimates of CVD risk and may increase their risk to a level worthy of interventions that have been shown to reduce CVD events in diabetes patients.
Know that there is insufficient evidence that screening for diabetes in persons at low risk for CVD reduces adverse outcomes.
Recognize that one-time screening with an FBG test for type 2 diabetes in all adults aged 25 or older may reduce the lifetime incidence of diabetes complications and result in gains in both QALY and life-years.
Appreciate that the benefits of screening for type 2 diabetes depend largely on the baseline CVD risk and that the benefits may outweigh the harms for persons with a 10-year CVD risk of over 8% to 10%.
From the ACP Diabetes Care Guide
This chapter includes information on the following topics related to screening and diagnosis of diabetes:
Types of Diabetes
- How is diabetes classified? [Type 1 Diabetes Mellitus, Type 2 Diabetes Mellitus, Diabetes of Defined Etiology, Gestational Diabetes]
- How is diabetes diagnosed?
- What are the differences among the tests used for diagnosing diabetes? [Fasting Plasma Glucose, Oral Glucose Tolerance Test, Hemoglobin A1C]
- What is prediabetes?
- What educational issues should I discuss with patients with prediabetes?
- What educational issues should I discuss with patients with a new diagnosis of diabetes?
Screening for Diabetes (Who should be screened for diabetes?)
Gestational Diabetes
- Who should be screened for gestational diabetes?
- How is gestational diabetes managed?
- What educational issues should I discuss with women with gestational diabetes?
You may order free copies of the complete ACP Diabetes Care Guide (book and CD-ROM).
SPECIAL NOTE: Page 30 has been revised.
From the ACP Diabetes Care Guide
Lifestyle Measures
Several randomized controlled trials have confirmed the importance of weight loss, increased physical activity, and a high-fiber diet low in calories and fat in slowing the progression of prediabetes (impaired glucose tolerance [IGT] or impaired fasting glucose) to overt diabetes. Health care professionals can play an important role in promoting these lifestyle changes. At all ages, the risk of type 2 diabetes increases with increasing body weight. The incidence of type 2 diabetes is highest in persons with upper body or abdominal obesity (a waist-to-hip circumference ratio >0.95 in men and >0.85 in women). In addition, numerous prospective studies have found an association between increased physical activity and a lower incidence of type 2 diabetes.
Pharmacologic Approaches
Although several studies have examined the use of medications to delay progression to diabetes, pharmacologic agents are not currently recommended for this purpose. The greater benefit of weight loss and physical activity strongly suggests that lifestyle modification should be the first choice to prevent or delay diabetes.
NOTE: You may order free copies of the complete ACP Diabetes Care Guide (book and CD-ROM).
From the ACP Diabetes Care Guide
Several ethnic groups, including Hispanic Americans, African Americans, Asian Americans, Native Americans, and Pacific Islanders, have a higher prevalence of type 2 diabetes, impaired glucose intolerance, and gestational diabetes than white Americans have. Diabetes-related morbidity and mortality is also higher in these groups. Several theories have been proposed to explain these differences ("thrifty genotype", environmental changes and western lifestyle, and socioeconomic factors).
NOTE: You may order free copies of the complete ACP Diabetes Care Guide (book and CD-ROM).
This session answers the following questions:
- What are the indications for initiating exenatide treatment in type 2 diabetes?
- What should be done with oral therapy for patients now requiring insulin for control of their diabetes?
- How should the new basal insulin analogues (glargine, determir) and rapidly active insulin analogues (lispro, aspart, glulisine) be used? Are there important differences between agents?
- Can diabetes be prevented? If so, how and in whom? Is there a role for thiazolidinediones?
The American College of Physicians currently considers patients with a body mass index (BMI) >30 as obese, and those with a BMI between 25 and 29.9 as overweight.
The recently published Dietary Guidelines for Americans 2005 recommend at least 60 minutes per day of moderate activity for the prevention of weight gain and up to 90 minutes per day of moderate activity for weight reduction.
Physical activity and fitness reduce morbidity and mortality for coronary artery disease, hypertension, obesity, diabetes, and osteoporosis.
Note: Subscription to MKSAP 14 is required to view this material. For more information, visit www.acponline.org.
Recently, interest has emerged in the prevention of type 2 diabetes in patients with prediabetes (impaired glucose tolerance, impaired fasting glucose), with most of the attention focused on improving insulin sensitivity through either lifestyle modifications or drug therapy.
Two recent studies demonstrated risk reduction in the progression to diabetes in obese, middle-aged individuals with impaired glucose tolerance. However, the active therapy groups in these studies required significant support, including nutritionists, exercise physiologists, and behavior modification experts.
Note: Subscription to MKSAP 14 is required to view this material. For more information, visit www.acponline.org.
Background:
The metabolic syndrome is a high-risk state for diabetes and cardiovascular disease. Little is known about its prevalence and prevention in those with impaired glucose tolerance.
Objective:
To determine the prevalence of the metabolic syndrome at baseline in the Diabetes Prevention Program and the effect of intensive lifestyle intervention and metformin therapy on the syndrome's incidence and resolution.
Design:
Randomized, controlled clinical trial.
Setting:
Research and community-based centers.
Participants:
Participants had impaired glucose tolerance (World Health Organization criteria plus fasting plasma glucose level >=5.3 mmol/L [>=95 mg/dL]) and were followed for a mean of 3.2 years after random assignment to intensive lifestyle intervention, metformin therapy, or placebo.
Interventions:
Metformin, 850 mg twice daily, or intensive lifestyle intervention designed to achieve and maintain a 7% weight loss and 150 minutes of exercise per week.
Measurements:
The metabolic syndrome was defined as having 3 or more characteristics (waist circumference; blood pressure; and levels of high-density lipoprotein cholesterol, triglycerides, and fasting plasma glucose) that met criteria from the National Cholesterol Education Program Adult Treatment Panel III.
Results:
Fifty-three percent of participants (n = 1711) had the metabolic syndrome at baseline; incidence did not vary substantially by age. However, low levels of high-density lipoprotein cholesterol predominated in younger participants (age 25 to 44 years), and high blood pressure predominated in older participants (age 60 to 82 years). In life-table analyses (log-rank test), incidence of the metabolic syndrome was reduced by 41% in the lifestyle group (P < 0.001) and by 17% in the metformin group (P = 0.03) compared with placebo. Three-year cumulative incidences were 51%, 45%, and 34% in the placebo, metformin, and lifestyle groups, respectively. There was no significant heterogeneity by ethnic group.
Limitations:
The study involved a volunteer group with impaired glucose tolerance, which limits generalizability.
Conclusions:
The metabolic syndrome affected approximately half of the participants in the Diabetes Prevention Program at baseline. Both lifestyle intervention and metformin therapy reduced the development of the syndrome in the remaining participants.
It is nearly impossible to be a practicing internist in the United States and have a day of clinical work pass without encountering at least 1 patient with type 2 diabetes. Currently, over 20 million Americans and over 150 million worldwide have type 2 diabetes. Models estimate that this number will nearly double by the year 2050 so that about one third of adult Americans will have the disease.
This In the Clinic feature includes answers to these and other practical, clinical questions:
- What are the diagnostic criteria for type 2 diabetes in nonpregnant adults?
- Should we screen for type 2 diabetes?
- Can we prevent type 2 diabetes?
- What should the initial evaluation of patients with newly diagnosed type 2 diabetes include?
- What measures do U.S. stakeholders use to evaluate the quality of care for patients with type 2 diabetes?
NOTE: Only ACP members and individual subscribers can access the electronic features of In the Clinic. Non-subscribers who wish to access this issue of In the Clinic can elect "Pay for View."
How does someone decide whether to have a salad or ice cream with lunch? How do cancer patients choose between different courses of chemotherapy? While these questions vary greatly in their difficulty and significance, the key to understanding how people answer them lies in a still-developing field called behavioral economics.
"Behavioral economics brings together psychology and economics to better understand how people make decisions," said Kevin Volpp, ACP Member, assistant professor of medicine and health care systems at the University of Pennsylvania School of Medicine and the Wharton School in Philadelphia. The field grew out of some economists' recent realization that, contrary to traditional economic theory, people do not always make rational decisions or choose the course of action that is in their long-term interests.
Women with high blood pressure have a significantly higher risk of developing type 2 diabetes compared with those with optimal blood pressure, a new study found.
The Oct. 9 European Heart Journal prospective cohort study examined 38,172 U.S. female health professionals who were free of diabetes at baseline. Subjects were divided into four categories of self-reported blood pressure: less than 120/75 mm Hg, or optimal; 120-129/75-84 mm Hg, or normal; 130-139/85-89 mm Hg, or high-normal; and established hypertension. The latter meant the subject had a self-reported history of hypertension or of taking antihypertensive treatment, or a blood pressure of at least 140/90 mm Hg.
At 10.2 years of follow-up, 1,672 women had developed diabetes. Of all the women in the highest blood pressure group, 9.4% developed diabetes, compared with 5.7% in the high-normal group, 2.9% in the normal group and 1.4% in the optimal group. The study adjusted for age, body mass index, exercise level, family history, alcohol use and smoking.
Women whose blood pressure rose during the course of the study also had a greater risk of developing diabetes. If a woman's blood pressure rose but stayed in the "normal" range, her risk increased 26% compared with a woman whose blood pressure was stable or decreased. A woman whose blood pressure rose to become hypertensive had a 64% higher risk of developing diabetes.
While self-report of blood pressure is a possible limitation of the study, the validity of the approach was examined in the Nurses' Health Study, where 99% of self-reports were confirmed accurate, the authors said. The study thus provides strong evidence that baseline blood pressure and blood pressure progression are associated with a higher risk of type 2 diabetes, and clinicians should bear this in mind for patient management, they said.
A documentary on diabetes, for which physicians can earn CME credit, debuted on the Discovery Channel this month. The documentary, "Diabetes: A Global Epidemic" can also be viewed online or downloaded as a podcast.
The documentary is divided into four hour-long segments:
- Insulin initiation: glycemic control with postprandial glucose monitoring
- Effectively managing anticoagulation
- Insulin initiation: targeting type 2 diabetes
- Diabetes: A global epidemic
The series is supported by an unrestricted educational grant to Discovery Health from Novo Nordisk.
The U.S. Preventive Services Task Force, in an updated recommendations statement, says that physicians should screen for type 2 diabetes in asymptomatic adults with sustained blood pressure (either treated or untreated) greater than 135/80 mm Hg.
The USPSTF concludes that for adults with blood pressure of 135/80 or less, evidence of the value of screening for diabetes is lacking and the balance of benefits and harms cannot be determined.
The American College of Endocrinology last week issued its first guidelines on managing patients with pre-diabetes to assist physicians in identifying those at high risk and developing specific treatment plans aimed at preventing the full-blown disease.
The guidelines recommend intensive lifestyle control as the first line of defense against the development of diabetes, including reducing weight by 5%-10%; engaging in moderate exercise for 30-60 minutes a day, five days a week; and following a low-fat diet low in sodium. The authors define pre-diabetes as having a fasting glucose of 100-125 mg/dL or a two-hour post-glucose challenge of 140-199 mg/dL.
While there are no drugs approved specifically for the treatment of pre-diabetes, evidence suggests that metformin and acarbose may be effective for high-risk patients, such as those with cardiovascular disease or worsening glycemia, the guidelines state. The authors noted safety concerns with using thiazolidinediones and said there is insufficient evidence to recommend new agents such as GLP-1 receptor agonists, DPP3 inhibitors or meglitinides.
The American College of Endocrinology last week issued its first guidelines on managing patients with pre-diabetes, suggesting aggressive lifestyle control as the first line of defense in warding off full-blown disease, followed by selective drug treatment and frequent monitoring of symptoms. What are you doing in your practice to control symptoms in patients at risk for diabetes?
Post your comments on the blog.
By the numbers, prediabetes is clearly not an orphan disease. Yet, until recently, internists had very little guidance on how to treat patients who have the condition and reduce their risk of developing full-blown diabetes.
Earlier this year, the American Diabetes Association (ADA) issued updated recommendations on screening and prevention or delay of diabetes. Then, in July, the American College of Endocrinology (ACE) convened a consensus conference on the diagnosis and management of prediabetes.
"This was the first true scientific summit on prediabetes," said Daniel Einhorn, MD, a member of the ACE task force on preventing diabetes. Experts from around the world gathered to apply current research to a number of prediabetes issues, including diagnostic and screening criteria, treatment goals and appropriate therapy. "What we realized is that this gap between normal and overt diabetes is not a gap that is benign," said Dr. Einhorn.
However, given the limitations of existing research on prediabetes, even the new guidance released by the experts is uncertain, he cautioned. "It's a consensus conference because we don't really know for sure. There's no consensus conference on gravity."
Still, the experts were certain enough to make a few strong statements about appropriate treatment of prediabetes. "We feel very strongly that there needs to be a two-pronged approach: one directed at glucose, one directed at cardiovascular risk," Dr. Einhorn said.
Diagnosed diabetes in the U.S. rose by about 90% in the past decade, according to a CDC analysis. The CDC analyzed data from Behavioral Risk Factor Surveillance System (BRFSS) surveys from 1995-97 and 2005-07 by a phone survey that covered adults by state or territory. They published their results in the Oct. 31 Morbidity and Mortality Weekly Report.
Age-adjusted incidence of diabetes increased nearly 90% from 4.8 per 1,000 in 1995-97 to 9.1 (range among states, 5.0 to 12.8) in 2005-07. Age-adjusted incidence rates were significantly higher for 2005-07 than for the earlier period in 27 of the 33 states (P <0.05).
By U.S. Census region, the average age-adjusted incidence was greatest in the South (10.5 per 1,000; CI = 9.9-11.1). This was followed by the Northeast (8.6, CI = 7.8-9.4), West (8.5, CI = 7.7-9.3), and Midwest (7.4, CI= 6.6-8.2).
States with the greatest number of annual new cases in California (208,000), Texas (156,000) and Florida (139,000).
The Endocrine Society guideline focuses on the primary prevention of cardiovascular disease and type 2 diabetes in patients at metabolic risk. The presence of three or more risk factors, such as enlarged waist circumference, hypertension, and elevated plasma glucose levels, should alert a clinician to a patient at metabolic risk, the authors state. Among other recommendations, the guideline advises primary care physicians to incorporate regular screening procedures for metabolic risk factors into their practice and to have all patients at risk undergo a 10-year global risk assessment (i.e., calculate based on such factors as smoking, blood pressure, total cholesterol, diabetes) for cardiovascular disease to determine the targets for lipoprotein-lowering therapy. The guidelines appear in the November Journal of Clinical Endocrinology and Metabolism.
About one in four of all U.S. adults have prediabetes, but fewer than one in 20 has been told they have it.
The CDC compared questions about prediabetes asked for the first time in the 2006 National Health Interview Survey to laboratory test results in the 2003-06 National Health and Nutrition Examination Survey (NHANES). They defined prediabetes as impaired fasting glucose (plasma glucose level of 100 to <126 mg/dL after an overnight fast), impaired glucose tolerance (plasma glucose level of 140 to <200 mg/dL after a 2-hour oral glucose tolerance test), or both.
Among those few who had been told they have prediabetes, 68% tried to lose or control weight, 55% increased physical activity or exercise, 60% reduced dietary fat or calories, and 42% did all three.
The CDC published criteria for testing for prediabetes and diabetes in asymptomatic adults.
The American College of Endocrinology published a consensus statement on managing prediabetes.
A recent issue of ACP Internist features interviews with experts on simple lifestyle changes to control prediabetes.
Diabetes PHD (Personal Health Decisions), from the American Diabetes Association (ADA) and powered by the Archimedes simulation engine, is a powerful new risk assessment tool. It can be used to explore the effects of a wide variety of health care interventions, including losing weight, stopping smoking, and taking certain medications.
The 2007 ADA Clinical Practice Recommendations provide an in depth review of diabetes care and their current recommendations for practice.
The ADA has issued their 2008 Comprehensive Guidelines for Diabetes Care
Question
In patients with hypertension, do β-blockers increase risk for new-onset diabetes?
Conclusion
In patients with hypertension, first-line therapy with β-blockers is associated with increased risk for new-onset diabetes but does not affect risk for death or myocardial infarction compared with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, or calcium-channel blockers.
Question
In patients with hypertension or other cardiovascular risk factors, what are the relative odds of developing diabetes with long-term use of the various types of antihypertensive drugs?
Conclusions
In patients with hypertension or other cardiovascular risk factors, the antihypertensive drugs associated with the lowest risk for diabetes with long-term use are angiotensin-receptor blockers and angiotensin-converting-enzyme inhibitors. The drugs associated with the highest risk are β-blockers and diuretics.
Question
In older patients with isolated systolic hypertension (ISH) with or without diabetes, what is the long-term effectiveness of a diuretic-based, stepped-care antihypertensive therapy compared with placebo?
Conclusions
In older patients with isolated systolic hypertension, diuretic-based, stepped-care antihypertensive therapy reduced long-term cardiovascular mortality. Patients who had diabetes at baseline or who developed diabetes during follow-up and received stepped care had lower mortality rates than did those who received placebo.
Question
What are the benefits and harms for mother and baby of screening for and treating gestational diabetes mellitus (GDM)?
Conclusions
Little evidence exists on the benefits and harms of screening for gestational diabetes. Limited evidence suggests that treatment of gestational diabetes after 24 weeks of gestation may improve maternal and neonatal outcomes.
Question
In patients with impaired glucose tolerance (IGT), does acarbose reduce the risk for cardiovascular disease and hypertension?
Conclusion
In patients with impaired glucose tolerance, acarbose reduced the risk for cardiovascular disease and hypertension.
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