New US Data Show Positive Trends on HbA1c Awareness in Diabetes

November 14, 2017

Improvements in blood glucose control among patients with diabetes seem to have plateaued, new data indicate, but other diabetes-related trends are encouraging.

Findings from 2908 adults who participated in four separate phases of the National Health and Nutrition Examination Survey (NHANES) were published in the November 14 issue of the Journal of the American Medical Association by Saeid Shahraz, MD, PhD, of the Heller School of Social Policy and Management, Brandeis University, Waltham, Massachusetts, and colleagues.

Improvements in glycemic control between 1998 and 2010 have apparently leveled off, but reassuringly the median HbA1c is still hovering around 6.9%.  

However, about one in seven patients with diabetes had poor glycemic control — HbA1c above 9% — across the four survey periods (2007–2008, 2009–2010, 2011–2012, and 2013–2014).

At the same time, more patients report receiving HbA1c testing and being aware of their results and targets, although this trend is weaker among adults younger than 45 years.

One explanation for the findings regarding the plateauing of HbA1c levels, Dr Shahraz and colleagues suggest, may be that in 2012 the American Diabetes Association (ADA) raised the HbA1c target from 7% to 8% for older, frailer adults and those with multiple comorbidities,\ and has also has advised more individualized targets overall.  

But regarding younger adults, "focusing attention on this subgroup may be important especially because they would benefit most from treatment," they say.

Asked to comment, William T Cefalu, MD, ADA chief scientific, medical and mission officer, told Medscape Medical News, "We are pleased to see a strongly positive trend in people with diabetes both getting A1c testing done more regularly and knowing their A1c target. This information is critical to determine the best individualized treatment options for each person."

And, he added, "We're not surprised to see that average A1c levels have stayed relatively unchanged over time, and the average of 6.9% is clinically acceptable... ADA's practice guidelines call for most adults with diabetes to achieve an A1c of less than 7%, but for some patients with other health conditions or limited life expectancy a higher goal may be appropriate."

Glycemic Control Plateaus, Even as Awareness Increases

The 2908 NHANES participants had a mean age 62 years, were equal numbers men and women, and one-third white. As detailed, their median HbA1c didn't change significantly from 2007–2008 to 2013–2014, nor did the proportion with HbA1c > 9%.

However, the proportions of patients who reported having an HbA1c test within the past year did rise significantly, with almost 80% having had a test by the end of 2014, and the changes were similar in sex, race, and age subgroups.   

Similarly, a significant rise also occurred in the proportions of patients who were aware of their past year HbA1c result, with almost 75% aware by the later period. This change was significant in all groups except aged 20–44 (P for trend = .16). 

And patients' awareness of the HbA1c target set by their clinicians also rose significantly, to almost 90%. Here again, the change was significant for all subgroups except young adults aged 20–44 (P for trend = .81).

Outcomes for All Patients Between First and Last Survey Periods


n = 757 (%)

n = 722 (%)
P for trend
HbA1c > 9% 13.7 15.0 .99
HbA1c < 7% 55.2 54.4 .99
HbA1c test in past year  55.1 77.8 .001
Patients aware of HbA1c result 52.3 74.3 .001
Patients aware of HbA1c target  74.1 89.7 .001

Dr Cefalu said, "Clinicians should continue their good work of doing the appropriate testing with their patients and including patients in goal setting.

"It is critical that the multidisciplinary diabetes care team develops an individualized care plan to meet the unique needs of each patient with diabetes,” he added.

"The ADA's practice guidelines call for all patients with diabetes to have an A1c test two to four times a year, depending on how well the individual patient is doing with their diabetes management. We're pleased that there has been a significant improvement in how clinicians and their patients are following these guidelines and hope and expect that these positive trends will continue."

The authors report no relevant financial relationships. Dr Cefalu is an employee of the American Diabetes Association. He has reported no further relevant financial relationships.

JAMA. 2017;318:1825-1827. Abstract

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