New research suggests HbA1c may be the most effective method to identify patients with undiagnosed prediabetes.
Point-of-care testing enhances the screening ability in primary-care settings. The findings were published recently in the Annals of Family Medicine. According to the researchers, “Diabetes and prediabetes need to be on our radar as possible diagnoses. In the United States, we need to be thoughtful and aggressive in screening.”
The data suggest that for screening purposes, HbA1c is a better test than a fasting blood glucose because post-meal glucose spikes happen sooner in the course of developing type 2 diabetes than a high fasting blood sugar.
It could very well be that if we were using A1c tests, we could catch more people with prediabetes and diabetes. Plus, the use of a point-of-care HbA1c machine enabled detection of prediabetes and diabetes cases in a timelier manner compared with the use of an outside lab.
Dr. Heather Whitley published a previous article comparing the features of three currently available point-of-care HbA1c tests, one of which is a handheld device and the other two are bench-top models (Diabetes Spectr. 2015;28:201-208).
This prospective longitudinal study compares diabetes screenings between standard practices vs systematically offered point-of-care (POC) hemoglobin A1c (HbA1c) tests in patients age 45 years or older. Systematically screened participants (n = 164) identified 63% (n = 104) with unknown hyperglycemia and 53% (n = 88) in prediabetes. The standard practice (n = 324) screened 22% (n = 73), most commonly by blood glucose (96%); 8% (n = 6) and 33% (n = 24) were found to have diabetes and prediabetes, respectively. The association between screening outcome and screening method was statistically significant (P = 0.005) in favor of HbA1c. HbA1c may be the most effective method to identify patients unknowingly living in hyperglycemia. Point-of-care tests further facilitate screening evaluation in a timely and feasible fashion.
The latest study was done in a single family-medicine clinic from April 2013 through March 2014. A total of 689 patients were seen and evaluated for eligibility; 164 who met the American Diabetes Association’s screening age cutoff of 45 years (and older) and were without exclusion criteria were screened using a point-of-care HbA1c test. Another 709 patients underwent usual clinic care. After exclusions, 324 were evaluated by chart review.
Most of the patients (87%) were white, 55% were female, mean age was 63 years, and mean body-mass index was 31.0 kg/m2.
In the active screening arm [HbA1c point-of-care test], just 37% of the patients had an HbA1c of 5.6% or below (normoglycemia). Over half (53%) met the HbA1c criteria for prediabetes (5.7%–6.4%), while 10% were in the diabetes range (≥6.5%).
In the standard-practice arm, 22% (73) of the 324 evaluated persons were tested, most often by blood glucose (96%, typically as part of a larger venipuncture chemistry panel and not always fasting). Only four individuals received HbA1c testing, and one got both. Of these, 33% (24) were in the prediabetes range and 8% (six) tested in the diabetes range, while the majority (59%) tested euglycemic (n=43). The association between screening outcome and screening method was statistically significant in favor of HbA1c (P = .005).
In a post hoc analysis, Dr. Whitley and colleagues reanalyzed their data using the screening criteria of the United States Preventative Services Task Force (USPSTF) for overweight or obese patients ages 40 to 70 years. Those recommendations reduced the number of people screened from 164 [using ADA criteria] to 104 and missed identifying 36 patients with prediabetes and six with diabetes HbA1c levels. “Regardless of guidelines used, the analysis shows that systematically screening patients is more effective than standard screening practices,” Dr. Whitley wrote.
Most important is that when using the point of care testing, you get the results in a few minutes; then you can implement something to improve that care during that visit.
- Getting the results instantly can provide the time to discuss with the patient the importance of lifestyle.
- Early diagnosis of prediabetes can make a major difference in improving the quality of life of patients.
- The final results show the importance of early screening. Over half (53%) met the HbA1c criteria for prediabetes (5.7%–6.4%), while 10% were in the diabetes range (≥6.5%).
Ann Fam Med. 2017;15:162-164. Abstract