[Diabetes-talk] FW: [acb-diabetics] Glycemic targets and A1C

[Mike Freeman]

The article below is most interesting and, frankly, the results don’t surprise me. I confess, however, to wishing that people doing such studies would aim for tens of thousands of participants rather than a few hundred.

 

As I say, the results shown below make some sense to me. However, it’s hard for me not to have the lurking suspicion that “publish or perish” is alive and well.

 

Mike Freeman

 

 

From: acb-diabetics-bounces at acb.org [mailto:acb-diabetics-bounces at acb.org] On Behalf Of Nancy Matulis
Sent: Thursday, February 13, 2014 12:38 PM
To: acb-diabetics at acb.org
Subject: [acb-diabetics] Glycemic targets and A1C

 

Current glycemic targets advised for diabetes patients don't align with recommended HbA 1c levels, a new analysis of continuous glucose monitoring data suggests.

The findings, from the A 1c-Derived Average Glucose (ADAG) study, were published online <http://care.diabetesjournals.org/content/early/2014/02/04/dc13-2173.abstract>  February 10 in Diabetes Care by Nancy Wei, MD, from the Diabetes Center at Massachusetts General Hospital, Harvard Medical School, Boston, and colleagues.

Professional societies' recommendations for diabetes management advise HbA 1c goals of 6.5% or less, or less than 7%, with individualization based on a variety of factors. But HbA1c is measured only once every 3 months, and day-to-day self-management of diabetes to achieve and maintain the individualized target HbA 1c is facilitated by self-monitored blood glucose (SMBG) values, especially in patients treated with insulin.

Accordingly, SMBG targets are provided to patients to achieve HbA 1c goals, but these are based predominantly on expert opinion and, as a result, vary widely, the investigators say. Consequently, "There is little to guide clinicians and patients on how to achieve…individualized, targets," they observe.

Lack of Correlation Has Serious Implications

The investigators set out to determine the average fasting, postprandial, and bedtime self-monitored blood glucose (SMBG) concentrations associated with specified HbA 1c levels using data from ADAG.

The multinational 12-week ADAG study compared continuous glucose monitoring (CGM) (Medtronic MiniMed), performed at baseline and 3 times at 4-week intervals for at least a 48-hour period, with glucose levels assessed every 5 minutes; regular finger-stick measures during CGM (eg, fasting, premeal, 90-minute postmeal, and bedtime); and monthly HbA 1c values in a total of 507 nonpregnant adults with HbA 1c levels between 5.5% and 8.5%.

The new results represent data from 237 patients with type 1 diabetes and 141 with type 2 diabetes from the original ADAG cohort and suggest that currently recommended fasting blood glucose targets are generally lower than needed to achieve target HbA 1c values, while some recommended postprandial targets may be too high.

For example, while most organizations advise that patients aim for fasting blood glucose levels less than 120 mg/dL, results from ADAG found that actual average fasting blood glucose was 122 mg/dL among patients with HbA 1c levels of 5.5% to 6.49% and 142 mg/dL among those with HbA 1c levels of 6.5% to 6.99%.

Postprandial (90-minute) blood glucose values from ADAG correlated better with published guidelines. However, while the American Diabetes Association recommends postmeal levels of "less than 180 mg/dL," mean postmeal blood glucose values in ADAG were 144 mg/dL for the patients with HbA 1c levels 5.5% to 6.49% and 164 mg/dL for those in the 6.5% to 6.99% range, suggesting that these goals may need to be reexamined as well.

The findings have serious implications, Dr. Wei and colleagues say.

"The consequences of using the previously published, nonempirical data may include pushing patients harder to achieve lower fasting levels than are actually required," they state.

"Considering the safety concerns surrounding hypoglycemia, in particular, nocturnal hypoglycemia and hypoglycemia unawareness, the current recommended glucose targets emphasizing lower fasting blood glucose and higher postprandial blood glucose should be reevaluated," they urge.

Separate Targets Not Necessary for Type 1 vs Type 2

Target blood glucose levels needed to achieve specific HbA 1c goals were generally similar for patients with type 1 and type 2 diabetes, suggesting that separate targets aren't necessary for the 2 patient groups, the authors say.

They emphasize that the choice of both HbA 1c goals and self-monitored blood glucose targets is complex and should be based on individual patient factors.

"We hope that these data will be used by professional societies, clinicians, and patients to guide the appropriate choice of glucose targets and treatment to achieve their individualized HbA 1c goal."

Dr. Wei was supported by a National Institute of Diabetes and Digestive and Kidney Diseases training grant. Disclosures for the coauthors are listed in the article.

Diabetes Care. Published online February 10, 2014. Abstract <http://care.diabetesjournals.org/content/early/2014/02/04/dc13-2173.abstract> 

 

Nancy Matulis

ACB Maine Secretary

Sent from my iPad

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