Growing Pains for Home-Alone Glycosylated Hemoglobin Monitoring

July 20, 2007

JACKSONVILLE, Fla. -- The proliferation of office-based point-of-care testing for glycosylated hemoglobin (HbA1c) makes home monitoring for diabetes patients seem a natural next step, but doubts have risen about its accuracy.

JACKSONVILLE, Fla., July 20 -- The proliferation of office-based point-of-care testing for glycosylated hemoglobin (HbA1c) makes home monitoring for type 1 diabetes patients seem a natural extension, but doubts have risen about its accuracy.

The gold standard for HbA1c testing had long been the laboratory assay, but venipuncture's unpopularity with children and desire for more rapid results led to small rapid-assay devices that need only a drop of blood.

The semi-disposable A1cNow+ device and its predecessor -- the A1cNow -- were designed to fit that bill. They have also been used by physicians caring for diabetes patients to get results in minutes, though endocrinologists more commonly use a similar device for office use called the DCA2000 Analyzer,

The DCA2000 has been shown to be highly accurate. But whether the same is true for the A1cNow products has been questioned, starting with the case of a boy here.

"Some of my patients were starting to use them, and one of them asked why at one point he had a very different result than he did two minutes earlier," said Larry Fox, M.D., of the Nemours Children's Clinic.

He said this prompted him to test the device in a study of 32 type 1 diabetic children.

In the test, about a third of simultaneous A1cNow measurements differed from each other by more than 0.5% (32% among 25 home-measured pairs and 34% among 29 office-measured pairs), Dr. Fox and colleagues reported in the January issue of Diabetes Care.

The DCA2000 was significantly more accurate than the A1cNow (P