Diabetes & Hemoglobin Testing

Evaluation of lowering the age tostart screening asymptomatic adults
in Brazil using HbA1c results
Authors: J. Myers,1 M.B. Toralles,2 A.B. Fernandes,3 1Bio-Rad Laboratories, Inc., Hercules, CA, USA, 2DNA LAB, Salvador, Brazil,
3
Laboratório Lustosa, Belo Horizonte, Brazil

Background

Globally, there are approximately 537 million adults aged 20–79 living with diabetes. Almost 1 in 2 (240 million)
adults living with diabetes is undiagnosed.1 In Brazil, almost 1 in 3 (15.7 million) adults (20–79 years) living withdiabetes is undiagnosed.1
When prediabetes is diagnosed early, there is time for intervention before the development of type 2 diabetes andits complications. The Brazilian Diabetes Society follows similar guidelines to the American Diabetes Association(ADA) for diagnosing diabetes. The Brazilian Diabetes Society recommends beginning screening asymptomatic
adults from age 45.2 In January 2022, the ADA lowered the age to begin screening asymptomatic adults from45 to 35 years. This retrospective study will assess the impact of lowering the age of diabetes screening inasymptomatic adults to 35 years in a Brazilian population by evaluating the results when an HbA1c test is added
to a fasting plasma glucose test order.

MethodsPatients in the study attended three different clinics–
DNA LAB based in Salvador, Bahia, Laboratório Lustosain Belo Horizonte, Minas Gerais, and UNIMED inSão Carlos, São Paulo–from May 2021 to October 2021.
The patients were attending the clinic for either an annual
physical or for an unspecified medical concern.
All patients who had an order for a fasting plasma
glucose test were asked if they would like to participate
in a study to identify the risk for developing diabetes.
Those who agreed to participate were tested for both
fasting plasma glucose and %HbA1c. The data reviewed
included age, fasting plasma glucose (mg/dL), and%HbA1c. There were 839 patients ranging in age from30 to 60 years of age in the study.

Fasting plasma glucose was measured using hexokinase enzymatic
glucose methods on a Roche cobas c501 system with a non-diabetic
range of 60-90 mg/dL at one site, an Abbott ARCHITECT system witha non-diabetic range of 60-100 mg/dL at another site, and a Siemens
Atellica system with a non-diabetic range of 60-100 mg/dL at the thirdsite. %HbA1c was measured using ion-exchange HPLC systems, theBio-Rad Laboratories VARIANT™ II TURBO Hemoglobin Testing Systemat two sites and the Bio-Rad Laboratories D-10 Hemoglobin Testing
System at another site. Both HPLC systems used a non-diabetic rangeof ≤5.6% HbA1c, the prediabetic range from 5.7–6.4% HbA1c, and thediabetic range of ≥6.5% HbA1c. The HbA1c methods selected were IFCCand NGSP certified, met the criteria for diagnosing diabetes, and wereable to reveal hemoglobin variants.

Visit bio-rad.com/HbA1c/diabetes-screening-study for more information about HbA1c testing.

Diabetes and Hemoglobin Testing

Study Results
Of the 839 patients in the study, 189 had fasting plasma glucose
results outside of the normal range. The HbA1c results of theremaining 650 patients with normal fasting plasma glucose results
were evaluated to determine if adding an HbA1c test was able toidentify individuals at risk for developing diabetes. The data wasassessed for individuals from the original screening age of 45
through 60 compared with individuals in the lowered age range
from 35 through 60.

In the 45–60 screening age group, 48 of 650 patients had results
within the prediabetic or diabetic range–46 were prediabetic
and 2 individuals (aged 50–60) were diabetic. Of those in thelowered age range (aged 35–60), 78 of 650 were prediabetic and2 individuals (aged 50–60) were diabetic. In both age ranges, theadded HbA1c test identified more individuals than with normal
fasting plasma glucose alone–7% more, or 48 individuals, in the45–60 age range, and 12% more, or 80 individuals, in the 35–60
age range. Additionally, 10 patients under the age of 35 had
HbA1c results in the prediabetic range.

Number of individuals detected with elevated HbA1cwhen lowering the age of screening
80

Number of Individuals

7060
50Age Range40■ 45–60

30■ 35–60

20
1048

80

0Age Range
45–60

35–60

30–60

Individuals with prediabetes (HbA1c = 5.7–6.4%)

467888

Individuals with diabetes (HbA1c = ≥6.5%)

222Total

48

8090

Conclusion
Beginning screening for diabetes at age 35 and adding an HbA1c test is useful in detecting more at-risk, asymptomatic adults for prediabetes
than testing with fasting plasma glucose alone. Individuals at risk of developing diabetes can be treated earlier to prevent or delay complications.
Acknowledgments
I would like to acknowledge the work and contribution of the staff of Laboratório Lustosa in Belo Horizonte, Minas Gerais, the staff ofDNA Lab in Salvador, Bahia, and the staff of Laboratório Unilab—Unimed São Carlos in São Carlos, São Paulo. I would also like toacknowledge Humberto Ferreira from Bio-Rad Laboratories for his support.
REFERENCES
1. Magliano DJ, Boyko EJ; IDF Diabetes Atlas 10th edition scientific committee (2021) IDF DIABETES ATLAS [Internet]. 10th edition. Brussels: International DiabetesFederation; 2021. Available at: https://www.diabetesatlas.org.
2. Cobas R et al. (2022). Diagnóstico do diabetes e rastreamento do diabetes tipo 2. Diretriz Oficial da Sociedade Brasileira de Diabetes. Available at https://diretriz.
diabetes.org.br/diagnostico-e-rastreamento-do-diabetes-tipo-2/.
3. ADA (2022). Standards of Medical Care in Diabetes–2022. Diabetes Care, 45 (Supplement 1), S17-S38.
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