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From Medscape:

New Guidelines Issued on Optimal Hemoglobin A1C Targets for Type 2 Diabetes
The American College of Physicians has issued a guidance statement derived from other organizations' guidelines on the optimal hemoglobin A1C targets for patients with type 2 diabetes.

September 17, 2007 — The American College of Physicians (ACP) has issued a guidance statement on the optimal hemoglobin A_1c targets for patients with type 2 diabetes. The statement is published in the September 18 issue of the Annals of Internal Medicine.

"This guidance statement is derived from other organizations' guidelines and is based on an evaluation of the strengths and weaknesses of the available guidelines," write Amir Qaseem, MD, PhD, MHA, from the ACP in Philadelphia, and colleagues from the Clinical Efficacy Assessment Subcommittee of the ACP. "We used the Appraisal of Guidelines, Research and Evaluation in Europe (AGREE) appraisal instrument to evaluate the guidelines from various organizations."

The reviewed guidelines differed in whether they recommended a specific hemoglobin A_1c target, as well as in their choice of a specific target hemoglobin A_1c level. Except for the American Academy of Family Physicians guidelines, all guidelines specified hemoglobin A_1c target levels. Although most guidelines recommend a target hemoglobin A_1c level of approximately 7%, several guidelines recommend tailoring the target hemoglobin A_1c based on individual patient factors, including risk for microvascular and macrovascular complications, life expectancy, and comorbid conditions. All the reviewed guidelines agreed that target hemoglobin A_1c levels should be individualized for specific patients.

After reviewing the available guidelines, the ACP committee issued 3 summary statements:

Statement 1: The goal for glycemic control should be set as low as is feasible to prevent microvascular complications of diabetes, while avoiding undue risk for adverse events or placing an unacceptable burden on patients. Discussing with the patient the risks and benefits of specific levels of glycemic control should precede setting treatment goals.

Based on individualized assessment, a hemoglobin A_1c level less than 7% is a reasonable target for many patients, but not for all. Hemoglobin A_1c goals higher than 7% may be indicated for patients who are elderly or frail, who are at higher risk for adverse events from tight control, or who have substantially lowered life expectancy from comorbid conditions. More stringent targets may be indicated in patients who are at increased risk for microvascular complications.

Statement 2: Individualized evaluation of risk for complications from diabetes, comorbidity, life expectancy, and patient preferences should determine the specific goal for hemoglobin A_1c level.

Statement 3: The ACP committee recommends additional research to evaluate the optimal level of glycemic control, particularly in patients who have significant comorbid conditions.

"Understanding the benefits and harms of various levels of glycemic control remains challenging, particularly in patients with other comorbid conditions," the authors conclude. "In addition to the importance of glycemic control, management of blood pressure and lipid levels is also essential to prevent complications of diabetes. Further research that elucidates optimal level of glycemic control in patients of different ages, in patients with comorbid conditions, and in patient populations representative of those seen in practice would provide important additional guidance for management of diabetes."

The ACP supported creation of this statement. Some of the authors have disclosed various financial relationships with the Centers for Disease Control and Prevention, Novo Nordisk, Bristol-Myers Squibb, Pfizer Inc., and/or Merck Pharmaceuticals.

Ann Intern Med. 2007;147:417-422.

Clinical Context

Diabetes is a leading cause of morbidity and mortality in the United States, with approximately 20.8 million affected (7% of the population) and more than 90% with type 2 diabetes, and hemoglobin A_1c, known as glycosylated or glycated hemoglobin, is used as a measure of control of diabetes. Glycemic control for patients with diabetes was a priority area identified by the Institute of Medicine in the quality chasm report.

This is a synthesis of recommendations from guidelines developed by organizations, as assessed by the ACP Efficacy Assessment Subcommittee using the AGREE criteria, with 23 questions in 6 domains of scope and purpose, stakeholder involvement, rigor, clarity, applicability, and editorial independence.

Study Highlights

A MEDLINE search was conducted that identified 416 articles of which primary research articles and duplicate and outdated references were excluded.
2 independent reviewers scored the articles and ranked them using quantitative and qualitative criteria.
A group of 9 guidelines were identified for this review.
Individual guidelines were summarized as follows:
- The American Association of Clinical Endocrinologists (2002) recommended normalization of glucose levels with suggested hemoglobin A_1c levels of 6.5% or less, based on consensus but not systematic literature review.
- The American Academy of Family Physicians (1999-2005) did not set a uniform target for hemoglobin A_1c but recommended individual customized goals, and the guideline has not been updated since 1999.
- The American Diabetes Association (2006) recommended a stringent level of less than 6% for hemoglobin A_1c with less stringent levels for those with shorter life expectancy and for the elderly, but there is no reference to a systematic review.
- The American Geriatrics Society (2003) recommended hemoglobin A_1c levels of 7% or lower for healthy adults and less stringent levels of less than 8% for those with life expectancy of less than 5 years, based on a comprehensive review.
- The Canadian Diabetes Association (2003) recommended a level of 7% or lower to reduce risk for microvascular and macrovascular complications with even lower levels of less than 6% if it could be achieved without risk.
- The Institute for Clinical Systems Improvement (2004) recommended individualizing the target hemoglobin A_1c level and having a target of less than 7% except for those with advanced age, those at risk of hypoglycemia, or those with limited life expectancy.
- The National Institute of Health and Clinical Excellence (2002) recommended a level between 6.5% and 7.5% based on comprehensive evidence.
- The Scottish Intercollegiate Guidelines Network (2001) and the Veterans Health Administration (2003) both recommend a level below 7%.
Summary statements for review:
- All guidelines recommended setting individual goal levels, and most recommended targets of around 7%.
- Some guidelines recommended less stringent levels for older or frail patients and those with short life expectancy.
- The goal for glycemic control should be a hemoglobin A_1c level that is as low as possible without undue risk for adverse events or an unacceptable burden on patients.
- Individual assessment of risk for complications, comorbidity, life expectancy, and patient preference should be taken into account in setting individual goals.
- Further research should be conducted on the optimal hemoglobin A_1c level, particularly in the presence of comorbidities.

Pearls for Practice

A target of around 7% and below for hemoglobin A_1c level is recommended by most guidelines on diabetes glycemic control except for those by the American Academy of Family Physicians, which provides no target level.
Individualized goal-setting for hemoglobin A_1c level should take into account risk for complications, comorbidities, risk for hypoglycemia, age, life expectancy, and patient preference.