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Guidelines Ease Up on Glycemic Control for Some Patients With Type 2 Diabetes
 
 
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Mike Mitka
JAMA. June 6 2012

from Guidelines: "Weight reduction, achieved through dietary means alone or with adjunctive medical or surgical intervention, improves glycemic control and other cardiovascular risk factors.....Foods high in fiber (such as vegetables, fruits, whole grains, and legumes), low-fat dairy products, and fresh fish should be emphasized......As much physical activity as possible should be promoted, ideally aiming for at least 150 min/week of moderate activity including aerobic, resistance, and flexibility training"

Physicians are being told to loosen up on glycemic control when treating certain patients with type 2 diabetes.

Aggressive glucose management has been a mainstay of diabetes treatment, intended to reduce microvascular risks such as diabetic nephropathy, neuropathy, and retinopathy. Physicians treating patients with diabetes have traditionally set a goal of achieving and keeping glycated hemoglobin (HbA1c) levels below 7.0%. But recent trials have suggested that achieving such a level may put certain patients with diabetes at risk for cardiovascular complications and mortality.

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Age and risk for cardiovascular complications should be considered when setting target levels for glycemic control in patients with type 2 diabetes.

Acknowledging these recent studies, the American Diabetes Association and the European Association for the Study of Diabetes released a consensus report April 19 calling for a more patient-centered treatment approach that takes into account patient needs, preferences, and tolerances (Inzucchi SE et al. Diabetes Care. doi:10.2337/dc12-0413 [published online April 19, 2012]).

from Diabetes Care report......"hypoglycemia may exacerbate myocardial ischemia and may cause dysrhythmias (111)......

In 2008, three shorter-term studies [Action to Control Cardiovascular Risk in Diabetes (ACCORD) (34), Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified-Release Controlled Evaluation (ADVANCE) (35), Veterans Affairs Diabetes Trial (VADT) (36)] reported the effects of two levels of glycemic control on cardiovascular end points in middle-aged and older individuals with well-established type 2 diabetes at high risk for cardiovascular events. ACCORD and VADT aimed for an HbA1c <6.0% using complex combinations of oral agents and insulin. ADVANCE aimed for an HbA1c 6.5% using a less intensive approach based on the sulfonylurea gliclazide. None of the trials demonstrated a statistically significant reduction in the primary combined cardiovascular end points. Indeed, in ACCORD, a 22% increase in total mortality with intensive therapy was observed, mainly driven by cardiovascular mortality. An explanation for this finding has remained elusive, although rates of hypoglycemia were threefold higher with intensive treatment. It remains unclear, however, if hypoglycemia was responsible for the adverse outcomes, or if other factors, such as more weight gain, or simply the greater complexity of therapy, contributed. There were suggestions in these trials that patients without overt CVD, with shorter duration of disease, and lower baseline HbA1c, benefited from the more intensive strategies. Modest improvements in some microvascular end points in the studies were likewise demonstrated. Finally, a meta-analysis of cardiovascular outcomes in these trials suggested that every HbA1c reduction of ~1% may be associated with a 15% relative risk reduction in nonfatal myocardial infarction, but without benefits on stroke or all-cause mortality (36).

The report notes that lowering HbA1c to less than 7.0% is still recommended for most patients with diabetes. However, less stringent goals of between 7.0% to slightly higher than 8.0% are appropriate for patients with a history of severe hypoglycemia; limited life expectancy; advanced complications; extensive comorbid conditions; or difficulty attaining that 7.0% target despite intensive self-management education, repeated counseling, and effective doses of multiple glucose-lowering agents, including insulin. The report authors added that a goal of 6.5% might be considered in selected patients with short disease duration, long life expectancy, and no significant cardiovascular disease if it can be achieved without significant hypoglycemia or other adverse effects of treatment."


These multiple targets emerged in part because of a 2010 study that found a U-shaped risk curve: those with the lowest rate of all-cause mortality had an HbA1c of 7.5%, while those with higher and lower HbA1c levels saw an increased risk for all-cause mortality and cardiac events (Currie CJ et al. Lancet. 2010;375[9713]:481-489). The other study that raised questions about aggressive glucose management for all was the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial of 2008. That trial found that patients randomized to intensive therapy targeting a 6.0% or lower HbA1c level were 22% more likely to experience a nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes when compared with patients randomized to standard therapy with a target HbA1c level of 7.0% to 7.9% (N Engl J Med. 2008;358[24]:2545-2559).

"In terms of choosing a target, the studies have been murky; no study says it should be 7% for everybody," said Vivian Fonseca, MD, president of the American Diabetes Association. "The goal of 7% came from a study of patients with type 1 diabetes, and achieving an HbA1c of 7% seemed to balance the benefits and risks of glycemic control."

Beyond suggesting alternative HbA1c levels for various types of patients with diabetes, the consensus report also notes that lifestyle interventions, weight management, diet, and exercise remain key factors for minimizing diabetes complications.

Another important element of the report addresses the growing array of pharmacological agents available for diabetes treatment and their possible adverse effects. Metformin remains the optimal first-line drug for glucose management. If metformin does not enable a patient to achieve or maintain a personalized target HbA1c level, adding another 1 or 2 oral or injectable agents is considered reasonable. But the report authors cannot say with certainty which additional medications are best because of a "distinct paucity of long-term comparative effectiveness trials available."

The report authors emphasized their document is less prescriptive and less algorithmic than earlier guidelines and should serve as one of the tools available to physicians and patients as they discuss treatment options. Fonseca, who is also a professor of medicine at Tulane University's School of Medicine in New Orleans, said moving away from rigid guidelines is probably best for individual patients. "One of the problems with evidence-based medicine, which I support in general, is it can make physicians develop a one-size-fits-all approach to treating patients," he said.

Fonseca added that the less rigid guidelines also allow flexibility to change treatment courses over a patient's lifetime. "You have to recognize that people are different and their perspectives of things change; a continuing dialogue between patients and physician is very important," he said. "So determine goals and tailor therapy, but adjust over time."

from guidelines:

"Glycemic targets

The ADA's "Standards of Medical Care in Diabetes" recommends lowering HbA1c to <7.0% in most patients to reduce the incidence of microvascular disease (42). This can be achieved with a mean plasma glucose of ~8.3-8.9 mmol/L (~150-160 mg/dL); ideally, fasting and premeal glucose should be maintained at <7.2 mmol/L (<130 mg/dL) and the postprandial glucose at <10 mmol/L (<180 mg/dL). More stringent HbA1c targets (e.g., 6.0-6.5%) might be considered in selected patients (with short disease duration, long life expectancy, no significant CVD) if this can be achieved without significant hypoglycemia or other adverse effects of treatment (20,43). Conversely, less stringent HbA1c goals-e.g., 7.5-8.0% or even slightly higher-are appropriate for patients with a history of severe hypoglycemia, limited life expectancy, advanced complications, extensive comorbid conditions and those in whom the target is difficult to attain despite intensive self-management education, repeated counseling, and effective doses of multiple glucose-lowering agents, including insulin (20,44)."