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Diabetes management in the primary care setting: summary

2002; Elsevier BV; Volume: 113; Issue: 6 Linguagem: Inglês

10.1016/s0002-9343(02)01279-2

1555-7162

Kevin Peterson,

Diabetes Management and Education

The foregoing articles make it clear that the treatment of type 2 diabetes in everyday practice should strive to achieve the best possible control of blood glucose. This supplement underscores the inadequacies of current management in achieving this goal, given the nature of the disease and the hesitations of physicians and patients—particularly surrounding timely initiation of intensive therapy. Yet providers should be encouraged by the new concepts described by the authors of the articles in this supplement and others cited herein. These concepts may advance the ability of providers to confidently manage diabetes with greater success and to provide their patients with a meaningful clinical impact on vascular complications. Let us first review why the "best possible control" of blood glucose is so important. No message is more worthy of repetition than that of the major treatment trials of the 1990s1Diabetes Control and Complications Trial GroupThe effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus.N Engl J Med. 1993; 329: 977-986Crossref PubMed Scopus (23312) Google Scholar, 2UK Prospective Diabetes Study (UKPDS) GroupIntensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33).Lancet. 1998; 352: 837-853Abstract Full Text Full Text PDF PubMed Scopus (19427) Google Scholar, 3Ohkubo Y. Kishikawa H. Araki E. et al.Intensive insulin therapy prevents the progression of diabetic microvascular complications in Japanese patients with non-insulin-dependent diabetes mellitus a randomized prospective 6-year study.Diabetes Res Clin Pract. 1995; 28: 103-117Abstract Full Text PDF PubMed Scopus (2902) Google Scholar: improved glycemic control is associated with significantly reduced diabetic complications. In the UK Prospective Diabetes Study (UKPDS), intensive therapy with a sulfonylurea or insulin kept hemoglobin (Hb) A1c at 7% over 10 years and resulted in a 25% reduction in microvascular complications, compared with a 7.9% HbA1c in the conventionally managed group.2UK Prospective Diabetes Study (UKPDS) GroupIntensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33).Lancet. 1998; 352: 837-853Abstract Full Text Full Text PDF PubMed Scopus (19427) Google Scholar As Dr. Burton E. Sobel points out in his article, the evidence linking improved glucose control with long-term reduction of cardiovascular disease has not been as striking. In the UKPDS, the 16% reduction in heart attacks in the well-controlled patients was of borderline statistical significance (P = 0.054)2UK Prospective Diabetes Study (UKPDS) GroupIntensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33).Lancet. 1998; 352: 837-853Abstract Full Text Full Text PDF PubMed Scopus (19427) Google Scholar; however, it is clear from Dr. Sobel's review that better control of general risk factors and better glycemic control can work only to the patient's long-term advantage in terms of both cardiovascular and microvascular health. Compelling additional evidence is provided by the fact that intensive glucose control in the Diabetes Mellitus Insulin Glucose Infusion in Acute Myocardial Infarction (DIGAMI) study significantly reduced the 1-year mortality of patients with diabetes mellitus and acute myocardial infarction; fatal reinfarctions were among the deaths prevented.4Malmberg K. Diabetes Mellitus Insulin Glucose Infusion in Acute Myocardial Infarction (DIGAMI) Study GroupProspective randomised study of intensive insulin treatment on long term survival after acute myocardial infarction in patients with diabetes mellitus.BMJ. 1997; 314: 1512-1515Crossref PubMed Scopus (1220) Google Scholar Closer-to-normal blood glucose appears to have important effects on quality of life. Patients in a group with an average HbA1c of 7.5% rather than 9.3% over 12 weeks had significant improvements in symptom distress, general perceived health, cognitive functioning, overall visual acuity, sleep, vitality, and other areas, and they were much better able to work and live productively.5Testa M.A. Simonson D.C. Health economic benefits and quality of life during improved glycemic control in patients with type 2 diabetes mellitus a randomized, controlled, double-blind trial.JAMA. 1998; 280: 1490-1496Crossref PubMed Scopus (358) Google Scholar Although the incidence of mild hypoglycemic events increased in the UKPDS with intensified therapy, this did not result in additional complications. Consider how glycemic control is approached in everyday practice. The American Diabetes Association (ADA) currently recommends "target" and "action" levels for fasting and bedtime plasma glucose and for HbA1c (Table 1). The target HbA1c is 8%.6Skyler J.S. Insulin therapy in type 2 diabetes mellitus.in: DeFronzo R.A. Current Therapy of Diabetes Mellitus. Mosby-Year Book, St Louis, MO1998: 108-116Google Scholar The American College of Endocrinology recently took a stricter stance by designating an HbA1c of 6.5% as both a target and action level.7New US guidelines urge more aggressive treatment of diabetes. Washington, DC: Reuters Health; August 21, 2001Google Scholar By convention, glycemic targets are approached in a stepwise treatment regimen, based on the cornerstones of diet and exercise and with phases of drug treatment beginning with oral monotherapy and progressing to combined oral regimens. With few exceptions, insulin therapy is delayed until maximum doses of oral agents are inadequate. Insulin is typically begun in combination with an oral drug and then as multiple-injection monotherapy. As Dr. William T. Cefalu emphasizes in his article, however, this scheme is built to fail: after it temporarily recaptures glycemic control, it is beset by "secondary failures," leading to renewed periods of hyperglycemia and the need for intensified regimens.Table 1Glycemic Targets and Action Levels Recommended by the American Diabetes Association28American Diabetes AssociationStandards of medical care for patients with diabetes mellitus.Diabetes Care. 2002; 25: S33-S49Google ScholarIndexNondiabeticGoalAction SuggestedFasting preprandial plasma glucose<115 mg/dL (<6.4 mmol/L)80–120 mg/dL (<7.8 mmol/L) 140 mg/dL ( 7.8 mmol/L)Bedtime plasma glucose<120 mg/dL (5.6–7.8 mmol/L)100–140 mg/dL (5.6–8.9 mmol/L) 160 mg/dL ( 8.9 mmol/L)HbA1c (%)*Referenced to a nondiabetic range of 4% to 6%.<6.0% 8.0%HbA1c = glycated hemoglobin.* Referenced to a nondiabetic range of 4% to 6%. Open table in a new tab HbA1c = glycated hemoglobin. Against this background of chronic treatment failures, it should come as no surprise that 55% of patients with type 2 diabetes in primary care settings have HbA1c >7%, 37% have HbA1c >8%, and 23% have HbA1c >9%.8Harris M.I. Eastman R.C. Cowie C.C. et al.Racial and ethnic differences in glycemic control of adults with type 2 diabetes.Diabetes Care. 1999; 22: 403-408Crossref PubMed Scopus (573) Google Scholar It is little comfort to know that no medical specialty or practice setting appears to have a better record for glycemic control than others. In a study that followed 170 moderately ill patients with diabetes for 2 years, endocrinologists did about as well as family practitioners and general internists: HbA1c averaged >9% for each specialty. Patients all had similar HbA1c levels regardless of whether they received their care in fee-for-service, prepaid group, or health maintenance organization settings.9Greenfield S. Rogers W. Mangotich M. et al.Outcomes of patients with hypertension and non–insulin-dependent diabetes mellitus treated by different systems and specialties results from the medical outcomes study.JAMA. 1995; 274 ([serial on CD-ROM]): 1436-1444Crossref PubMed Scopus (358) Google Scholar More recent evidence suggests that the ADA guidelines can be achieved in a specialist (endocrinology) practice.10Miller C.D. Phillips L.S. Tate M.K. et al.Meeting American Diabetes Association guidelines in endocrinologist practice.Diabetes Care. 2000; 23: 444-448Crossref PubMed Scopus (65) Google Scholar Nevertheless, patients with diabetes can be seen as broadly failing to reap the benefits that intensive glucose control offers. They continue to incur heart disease at a rate 2 to 4 times that of nondiabetic patients,11National Diabetes Information Clearinghouse. Diabetes Statistics. Bethesda, MD: US Dept of Health and Human Services, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases;1999. NIH publication No. 99-3892. Available at: http://www.niddk.nih.gov/health/diabetes/pubs/dmstats/dmstats.htm. Accessed January 31, 2002Google Scholar possibly due to the unstable atherosclerosis that Dr. Sobel so eloquently links to the diabetic milieu and plasminogen activator inhibitor–1 (PAI-1). What stands in the way of better control of diabetes? First, the unfolding of the disease itself. Impairments in both insulin sensitivity and insulin secretion are present in most cases of type 2 diabetes.12Gerich J.E. The genetic basis of type 2 diabetes mellitus impaired insulin secretion versus impaired insulin sensitivity.Endocr Rev. 1998; 19: 491-503Crossref PubMed Scopus (0) Google Scholar Both components are believed to be genetically determined, and both may be present well in advance of frank diabetes. But, as Dr. LeRoith stresses, gradual impairment of insulin secretion is what enables diabetes development and contributes to secondary failure. No current drugs or techniques have been able to stop this decline in secretory function; not even the protocols and ideal conditions of the UKPDS could prevent deterioration across all treatment groups,2UK Prospective Diabetes Study (UKPDS) GroupIntensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33).Lancet. 1998; 352: 837-853Abstract Full Text Full Text PDF PubMed Scopus (19427) Google Scholar and the loss was faster when glucose levels were high at the outset,13Matthews D.R. Cull C.A. Stratton I.M. et al.UK Prospective Diabetes Study (UKPDS) GroupUKPDS 26 sulphonylurea failure in non-insulin-dependent diabetic patients over six years.Diabet Med. 1998; 15: 297-303Crossref PubMed Scopus (439) Google Scholar as is often the case in primary care settings. Glucose toxicity, caused by chronic hyperglycemia, is a further obstacle to good control because it aggravates the impairments in insulin secretion and sensitivity. It is, however, a productive target of treatment. Insulin therapy can overcome toxicity by restoring glycemic control, and in the process it ameliorates the impairments and improves the ability to maintain good control.6Skyler J.S. Insulin therapy in type 2 diabetes mellitus.in: DeFronzo R.A. Current Therapy of Diabetes Mellitus. Mosby-Year Book, St Louis, MO1998: 108-116Google Scholar Better glycemic control is also frustrated by barriers among patients.14Agency for Healthcare Research and Quality. Improving Care for Diabetes Patients Through Intensive Therapy and a Team Approach. Rockville, MD: US Dept of Health and Human Services, Agency for Healthcare Research and Quality; November 2001. AHRQ publication No. 02-0005. Research in Action, No. 2Google Scholar These barriers are frequently related to the complexity of the patient's condition. For example, acute illness and the need to greatly alter lifestyle or carry out the daily routine may seriously challenge patient compliance. On the other hand, the lack of symptoms in milder cases may remove an important incentive for compliance. Risk of hypoglycemia may be an issue, and the lack of patient education materials has also been cited as a barrier. One piece of evidence is a recent finding from a nationwide study by the Centers for Disease Control and Prevention. Among >1,000 people with diabetes aged ≥55, 73% were unaware that heart attack and stroke are the leading causes of death among people with diabetes. Only half of these individuals knew that they had a greater risk of heart attack and stroke than people without diabetes.15Davis J. Diabetics unaware of their risk: many don't even know they face serious chances of heart attack or stroke. WebMD Medical News. Available at: http://my.webmd.com/content/article/1667.51748. Accessed December 15, 2001Google Scholar Barriers to insulin therapy are especially strong mainly because of the need for injections. Dr. Cefalu mentions the negative attitudes of patients, including fears about pain from injections and errors in self-care, and the perception that insulin therapy signifies past failure of self-care, advanced illness, or even a prelude to death.16Hunt L.M. Valenzuela M.A. Pugh J.A. NIDDM patients' fears and hopes about insulin therapy the basis of patient reluctance.Diabetes Care. 1997; 20: 292-298Crossref PubMed Scopus (265) Google Scholar, 17Wallace T.M. Matthews D.R. Poor glycaemic control in type 2 diabetes a conspiracy of disease, suboptimal therapy and attitude.Q J Med. 2000; 93: 369-374Crossref Scopus (129) Google Scholar Not unexpectedly, reports show that patients with worse control tend to appreciate and accept insulin more readily, acknowledging that they feel better and more hopeful in taking it.16Hunt L.M. Valenzuela M.A. Pugh J.A. NIDDM patients' fears and hopes about insulin therapy the basis of patient reluctance.Diabetes Care. 1997; 20: 292-298Crossref PubMed Scopus (265) Google Scholar In overall management of diabetes, primary care providers face barriers such as the difficulty and labor-intensiveness of controlling glucose and effecting lifestyle changes, the complexity of both the disease and its treatment, and controversies over optimal management.18Larme A.C. Pugh J.A. Attitudes of primary care providers toward diabetes barriers to guideline implementation.Diabetes Care. 1998; 21: 1391-1396Crossref PubMed Scopus (226) Google Scholar The organization and structure of care delivery in the office may give rise to obstacles such as lack of support services.19Peterson K.A. Vinicor F. Strategies to improve diabetes care delivery.J Fam Pract. 1998; 47: S55-S62PubMed Google Scholar One troubling barrier is the reluctance of providers to intensify therapy during staged management when it is justified by glucose levels. This "clinical inertia," observed even in a diabetes clinic setting, may sometimes be acceptable. Reasons given by providers include the belief that the patient is improving or will not comply with intensified therapy—but it may truly reflect physician noncompliance with national standards.20El-Kebbi I.M. Ziemer D.C. Musey V.C. et al.Diabetes in urban African-Americans IX. Provider adherence to management protocols.Diabetes Care. 1997; 20: 698-703Crossref PubMed Scopus (57) Google Scholar, 21El-Kebbi I.M. Ziemer D.C. Gallina D.L. et al.Diabetes in urban African-Americans XV. Identification of barriers to provider adherence to management protocols.Diabetes Care. 1999; 22: 1617-1620Crossref PubMed Scopus (56) Google Scholar, 22Cook C.B. Ziemer D.C. El-Kebbi I.M. et al.Diabetes in urban African-Americans XVI. Overcoming clinical inertia improves glycemic control in patients with type 2 diabetes.Diabetes Care. 1999; 22: 1494-1500Crossref PubMed Scopus (86) Google Scholar It may also reflect the known tendency of providers to comply with patient concerns about insulin therapy and delay the use of insulin for as long as possible.17Wallace T.M. Matthews D.R. Poor glycaemic control in type 2 diabetes a conspiracy of disease, suboptimal therapy and attitude.Q J Med. 2000; 93: 369-374Crossref Scopus (129) Google Scholar A rational way to improve glycemic control is to address the barriers to it, which makes the improvement of insulin delivery a rational focus of research. Dr. Cefalu's article highlights the investigational journey toward injection alternatives, which appears to be culminating in effective and safe systems for delivering pulmonary insulin.23Cefalu W.T. Skyler J.S. Kourides I.A. et al.Inhaled Insulin Study GroupInhaled human insulin treatment in patients with type 2 diabetes mellitus.Ann Intern Med. 2001; 134: 203-207Crossref PubMed Scopus (213) Google Scholar Behaving similarly to (or better than) injected insulin, inhaled regimens and perhaps other transmembrane techniques have the potential to greatly improve the acceptability of insulin therapy and change perceptions that now stand in the way of earlier use of insulin. The idea of mimicking endogenous insulin secretion, which inhaled insulin accommodates, remains a worthy model for improving glycemic control and should become completely familiar to providers managing intensively. Although no medical specialty or practice setting has emerged with an edge on achieving glycemic control, some newer models of care have been advocated, particularly those with a structured approach or team concept focused on intensive therapy. These models have components such as regularly scheduled visits, detailed protocols and glucose targets, medical recommendations, involvement of accessible nurses and other nonphysicians, and patient and provider education (Table 2). 10Miller C.D. Phillips L.S. Tate M.K. et al.Meeting American Diabetes Association guidelines in endocrinologist practice.Diabetes Care. 2000; 23: 444-448Crossref PubMed Scopus (65) Google Scholar, 24Pollet R.J. El-Kebbi I.M. The applicability and implications of the DCCT to NIDDM the imperative for intensification of therapy by a primary care–subspecialty team approach.Diabetes Rev. 1994; 2: 413-427Google Scholar, 25Wagner E.H. Austin B.T. Von Korff M. Improving outcomes in chronic illness.Manag Care Q. 1994; 4: 12-25Google Scholar, 26Peters A.L. Davidson M.B. Application of a diabetes managed care program the feasibility of using nurses and a computer system to provide effective care.Diabetes Care. 1998; 21: 1037-1043Crossref PubMed Scopus (107) Google Scholar One model, in place at a practice of academic endocrinologists in Atlanta (Emory University), has a complex structure in which (1) many patients have ≥4 visits per year; (2) visits alternate between those with a physician and nurse practitioner together and those with just a nurse practitioner (or dietitian); (3) patients have direct telephone access to nurse practitioners and frequent adjustments to therapy between visits; (4) there is regular screening for eye and foot problems, nephropathy, coronary artery disease, lipid abnormalities, and hypertension; and (5) the providers aim for the ADA target levels of glycemic control by following a step-care approach.10Miller C.D. Phillips L.S. Tate M.K. et al.Meeting American Diabetes Association guidelines in endocrinologist practice.Diabetes Care. 2000; 23: 444-448Crossref PubMed Scopus (65) Google ScholarTable 2Components of a Team Approach to Intensive Therapy for Type 2 Diabetes10Miller C.D. Phillips L.S. Tate M.K. et al.Meeting American Diabetes Association guidelines in endocrinologist practice.Diabetes Care. 2000; 23: 444-448Crossref PubMed Scopus (65) Google Scholar, 14Agency for Healthcare Research and Quality. Improving Care for Diabetes Patients Through Intensive Therapy and a Team Approach. Rockville, MD: US Dept of Health and Human Services, Agency for Healthcare Research and Quality; November 2001. AHRQ publication No. 02-0005. Research in Action, No. 2Google Scholar, 21El-Kebbi I.M. Ziemer D.C. Gallina D.L. et al.Diabetes in urban African-Americans XV. Identification of barriers to provider adherence to management protocols.Diabetes Care. 1999; 22: 1617-1620Crossref PubMed Scopus (56) Google Scholar, 24Pollet R.J. El-Kebbi I.M. The applicability and implications of the DCCT to NIDDM the imperative for intensification of therapy by a primary care–subspecialty team approach.Diabetes Rev. 1994; 2: 413-427Google Scholar, 25Wagner E.H. Austin B.T. Von Korff M. Improving outcomes in chronic illness.Manag Care Q. 1994; 4: 12-25Google Scholar, 26Peters A.L. Davidson M.B. Application of a diabetes managed care program the feasibility of using nurses and a computer system to provide effective care.Diabetes Care. 1998; 21: 1037-1043Crossref PubMed Scopus (107) Google ScholarTeam management involving the primary care provider, nurse practitioner, dietitian, and "physician extenders"Detailed protocols for follow-up visits, glycemic targets, screening tests, and medications —More frequent use of combination oral therapy or oral-insulin combination —For insulin recipients, increased use of ≥3 daily injectionsDietary and behavioral education for patientProvider educationDirect telephone access to ancillary staffIntensified management of coexisting risk factorsUse of information systems for tracking processes and outcomes Open table in a new tab An important and consistent feature among successful diabetes programs is the consensual adoption by local providers of an evidence-based plan for care.27Wagner E. Austin B. VonKorf M. Organizing care for patients with chronic illness.Milbank Q. 1966; 76: 511-544Google Scholar Evidence-based evaluations for many aspects of diabetes care are now included in the ADA clinical recommendations for 2002.28American Diabetes AssociationStandards of medical care for patients with diabetes mellitus.Diabetes Care. 2002; 25: S33-S49Google Scholar Chronic disease care models, such as Wagner's Planned Care Model, help to illustrate the variety of influences important in determining the functional and clinical outcomes for a practice; however, in a practical sense, it is difficult to isolate these influences in a busy clinical environment.25Wagner E.H. Austin B.T. Von Korff M. Improving outcomes in chronic illness.Manag Care Q. 1994; 4: 12-25Google Scholar The Direct Observation of Primary Care (DOPC) study illustrates in a more detailed way the complexity of the organizational structures in primary care.29Stange K. Jaen C. Flocke S. et al.The value of a family physician.J Fam Pract. 1998; 46: 363-368PubMed Google Scholar Although the complexities of ambulatory clinical systems preclude identification of a simple solution, examination of an example of "best practice" can promote the identification of program features that have been successful in one clinical system and may prove useful in other situations.30Crabtree B. Miller W. Aita V. et al.Primary care practice and organization and preventive services delivery a qualitative analysis.J Fam Pract. 1998; 46: 403-409PubMed Google Scholar A retrospective study of 121 patients with type 2 diabetes treated for at least a year in the team structure approach described above found that only 5% had adequate glycemic control with diet alone. About 78% required more than diet or a single oral agent; almost 33% of patients used oral therapy plus insulin, and 26% used insulin alone. Of patients using any insulin, 42% took ≥3 injections a day. These efforts paid off, with an average HbA1c for the overall group of 6.9%; 61% of patients had levels <7%, and 87% had levels <8%. The researchers tied the results to the fact that, compared with primary care practices,8Harris M.I. Eastman R.C. Cowie C.C. et al.Racial and ethnic differences in glycemic control of adults with type 2 diabetes.Diabetes Care. 1999; 22: 403-408Crossref PubMed Scopus (573) Google Scholar they had fewer patients receiving diet alone, many more patients using an oral agent plus insulin, and many more taking ≥3 injections of insulin per day.10Miller C.D. Phillips L.S. Tate M.K. et al.Meeting American Diabetes Association guidelines in endocrinologist practice.Diabetes Care. 2000; 23: 444-448Crossref PubMed Scopus (65) Google Scholar These results are substantially better than those found in large samples of primary care physicians. The East Metro Disease Initiative (EMDI) is a quality improvement program for 27 community clinics sponsored by 2 hospital systems in St. Paul, Minnesota. A recent review of the EMDI database demonstrated that among 7,785 type 2 diabetes patients in St. Paul, Minnesota, 4,548 (58.4%) were on oral agents alone, 719 (9.2%) were on oral agents and insulin, and 1,213 (15.6%) were on insulin alone. Of the 1,812 patients where the dosage of insulin was known, 1,312 (72%) were on a twice-a-day injection schedule, and only 224 (12.4%) took ≥3 injections per day. The average HbA1c in this group was 7.84 % (K. Peterson, report from the East Metro Diabetes Initiative, unpublished data, March 2002). A structured approach that supports aggressive therapy has also been found to reduce clinical inertia. In 1995, the Atlanta practice strengthened its emphasis on earlier intensification of therapy, essentially placing less emphasis on lifestyle changes and asking physicians to retain patients in a given treatment category only if they had responded well there. Average HbA1c levels decreased from 8.4% in the 2 years leading up to 1995 to 7.6% in the year after. The improvement was associated with a pattern of earlier use and higher doses of sulfonylureas and insulin, reflecting improved provider adherence to intensification of therapy.22Cook C.B. Ziemer D.C. El-Kebbi I.M. et al.Diabetes in urban African-Americans XVI. Overcoming clinical inertia improves glycemic control in patients with type 2 diabetes.Diabetes Care. 1999; 22: 1494-1500Crossref PubMed Scopus (86) Google Scholar Type 2 diabetes can be considered a chronically and broadly undertreated disease. In the face of widespread knowledge of the benefits of near-normal glucose, an alarming number of patients do not follow even liberal standards for control; thus, they continue to carry a burden of high risk for all vascular complications of diabetes and cardiovascular disease.