Published in UAB Insight, Winter 2008
ABSTRACT: While guidelines define parameters for tight glycemic control of patients with diabetes, they must be individualized based on comorbidities, life expectancy, and patient preferences.
CME OBJECTIVE: The reader will understand how to evaluate patients and define the most appropriate level of control.
Richard S. Rosenthal, MD, consultant Novo Nordisk, Merck & Co, Sanofi Aventis
Tight glycemic control can significantly reduce complications of type 2 diabetes mellitus, and most guidelines issued by medical organizations advise setting hemoglobin A1c (HbA1c) goals around 7%. The guidelines differ, however, with regard to optimal levels (suggested HbA1c targets range from ≤6.5% to 7%) and management of patients with multiple comorbidities.
In an effort to reconcile recommendations, the American College of Physicians (ACP) evaluated strengths and weaknesses of existing guidelines and developed a statement to guide evidence-based care decisions. The ACP guidelines by Qaseem et al advise physicians to aim for the lowest hemoglobin HbA1c levels possible given a patient’s risk for diabetic complications and their comorbidities, life expectancy, and personal preferences (Ann Intern Med. 2007;147:417-422).
“Lower HbA1c levels reduce the risk of diabetic complications, but treatment goals must be tailored for each patient to avoid hypoglycemia — the major adverse effect of tight glycemic control,” says UAB endocrinologist Richard S. Rosenthal, MD.
Preventing Microvascular Disease
The ACP statement notes that an HbA1c below 7% is desirable, as tight glycemic control reduces complications from diabetes, particularly diabetic microvascular complications, which significantly increase morbidity and mortality. Qaseem et al recommend stringent HbA1c targets for patients at increased risk for microvascular complications.
“The use of multiple oral agents and even early insulinization may be necessary for some patients to reach the low target levels of HbA1c needed for optimal prevention of diabetic complications,” Rosenthal says. In the United States diabetic nephropathy is the leading cause of end-stage renal disease and diabetic retinopathy is the most frequent reason adults aged 20 to 74 years become blind (Diabetes Care. 2004;27[S1]:579-583;584-587).
Neuropathies also place considerable health burdens on patients and can be difficult to treat, says Rosenthal. “Better glycemic control is key to reducing neuropathies in patients with diabetes. While the introduction of newer agents such as pregabalin [Lyrica] has improved management to some extent, patients with diabetic neuropathies sometimes benefit from referral to a neurologist.” The Food and Drug Administration approved pregabalin in 2005 for management of neuropathic pain associated with diabetic peripheral neuropathy and postherpetic neuralgia.
Both Rosenthal and ACP guidelines suggest physicians discuss treatment goals with patients, understand their preferences with regard to diabetes management and overall care, and tailor HbA1c targets accordingly. “Tight glycemic control is the fundamental approach for minimizing development of disabling diabetic microvascular complications, but driving HbA1c too low can introduce other problems,” says Rosenthal, who notes these complications are more common among the elderly and individuals with multiple chronic illnesses.
Goals for Older Patients
In its 2008 position statement, the American Diabetes Association (ADA) says high clinical and functional heterogeneity seen in older adults significantly complicates treatment of these individuals. Older age alone, however, should not preclude intensive care, and the ADA writes, “Patients who can be expected to live long enough to reap the benefits of long-term intensive diabetes management [~10 years] and who are active, have good cognitive function, and are willing to undertake the responsibility for self-management…should be treated using the stated goals for younger adults with diabetes.” (Diabetes Care. 2008;31[S1]:S12-S54.)
Looser glycemic goals (≥7%), say both Rosenthal and the ADA, may be appropriate for those with advanced diabetic complications, life-limiting comorbid disease, and dementias.
“In these patients the risks of tight control, which include hypoglycemia, polypharmacy, and drug-drug and drug-disease interactions, sometimes outweigh benefits,” he says. Intensive management of blood pressure and lipids can produce positive effects in relatively short periods, and Rosenthal emphasizes the importance of reducing macrovascular endpoints through these measures.
Elderly patients with diabetes can have a reduced ability to recognize signs of hypoglycemia and are at heightened risk for this complication. A recent retrospective study of frail older adults with diabetes found that tight control (HbA1C ≤7%) increased the risk of falls, which are common among the elderly and are associated with morbidity, mortality, and loss of independence (J Am Geriatr Soc. 2007;55[12]:2092-2092).
The study found frail elders with HbA1c ≤7% had a 32% greater risk of falling compared with their counterparts who had more moderate levels of glycemic control. The authors note that more research is needed to evaluate the risks and benefits of relaxed glucose control in high-risk older adults.
The ACP writing panel stresses the value of individualized therapy for all patients, and especially for older, sicker adults, and closes its guidelines with a call for further research to assess optimal levels of glucose control in individual patients.
Pay for Performance
Delivering individualized treatment is a crucial component of high-quality health care. Yet, as pay-for-performance programs proliferate, more physicians are required to meet standardized health care measures on specific elements of a single disease. Some experts see potential conflicts between current pay-for-performance models and the inherent complexities of individual care, especially among patients with multiple chronic diseases.
Diabetes care is a high-priority target of pay-for-performance programs. The ACP statement on optimal HbA1c goals notes that when quality-of-care issues arise, glycemic control and other aspects of diabetes management are often cited as benchmarks for physician performance.
A number of investigators are now examining how individuals with multiple comorbid illnesses will fare in pay-for-performance systems. UAB researchers conducted a study, led by preventive medicine specialist Jewel H. Halanych, MD, MSC, to determine the association between comorbid illness burden and delivery of routine diabetes care (HbA1C testing, lipid testing, dilated eye examinations, and urinary microalbumin testing) in more than 6000 patients. Investigators found varying levels of comorbidities among patients did not alter testing patterns (Diabetes Care. 2007;30[12]:2999-3004).
Another study of diabetes care on pay-for-performance reported that although quality measurement programs increased the likelihood of patients receiving the two annual HbA1c tests recommended by the ADA, the model did not appear to contribute to improved glycemic control (J Health Care Poor Underserved. 2007;18[4]:966-983).
Halanych et al write, “In the pay-for-performance era, physicians may feel pressure to adopt a ‘one-size-fits-all’ approach and order tests to improve their performance on quality indicators developed from trials that excluded patients with multiple comorbid conditions. In patients with limited life expectancy the appropriate clinical course may be to decrease testing associated with delayed benefit and to focus on interventions with high short-term potential for improving quality of life.”
A position paper from the ACP echoes these concerns and others, noting that basing care on a limited set of practice parameters could result in the erosion of individualized therapy, the deselection of complex patients, and reduced trust between patients and physicians (Ann Intern Med. 2007;147:792-794).
Although Rosenthal says improvements produced by pay-for-performance systems are likely to take time to accrue, he does think patients can benefit from the rigorous care inherent in such programs. “Regularly checking HbA1c, blood pressure, lipids, and other measures will naturally compel physicians to address values that are not at appropriate goals,” he says.
For more information:
Dr. Richard Rosenthal
1.800.UAB.MIST
mist@uabmc.edu