Are the ADA Hemoglobin A1c Criteria Relevant for the Diagnosis of Type 2 Diabetes in Youth?

Abstract

Diagnostic criteria for diabetes in children have not been established with nearly the rigor as that employed in adults. Recently revised American Diabetes Association (ADA) criteria allowed utilization of hemoglobin A(1c) (HbA1c) ≥ 6.5 % for diagnosis of diabetes. A recent series of pediatric studies appear to show that HbA1c has lower sensitivity than Fasting plasma glucose (FPG) or oral glucose tolerance test (OGTT). However, FPG and OGTT have themselves never been validated in children. Studies to validate diagnostic thresholds in children appear unlikely to take place. Thus, accepting the major ADA diagnostic criteria appears to be the best course of action for the pediatric community. One area in which correlation studies between HbA1c and FPG or OGTT might shed light is in the definition of criteria for intervention in 'pre-diabetes,' as the Diabetes Prevention Program Trial did not use HbA1c. However, such treatment, and the exact diagnostic thresholds at which it should be initiated in children, remains unproven.

Type 2 diabetes in the child and adolescent

“… ○Casual is defined as any time of day without regard to time since last meal. ○Symptoms of diabetes include polyuria, polydipsia, nocturia, and unexplained weight loss. HbA1c > 6.5%. ○Must utilize a laboratory based, DCCT aligned, National Glycohemoglobin Standardization Program certified methodology. In the absence of symptoms, hyperglycemia detected incidentally or under conditions of acute physiologic stress may be transitory and should not be regarded as diagnostic of diabetes. Studies have raised concerns about the reproducibility of the oral glucose tolerance test (OGTT) in obese adolescents, with a concordance rate between repeat OGTTs a few weeks apart of approximately 30% . Although the HbA1c criterion has been accepted by the ADA for the diagnosis of diabetes in adults, this criterion remains controversial, as it identifies a population that does not overlap entirely with that identified by fasting or postglucose challenge criteria . However, HbA1c > 6.5% predicts the risk of retinopathy as well as the glucose criteria.…”

Endocrine Effects of Inhaled Corticosteroids in Children

“…Evidence about levels of fasting glucose and hemoglobin A 1c thresholds placing children into a higher DM risk category continues to be a point of debate; however, our team has chosen a fasting glucose level of 100 mg/dL and a hemoglobin A 1c level of 6.0% based on available data. 80,81 Conclusions Inhaled corticosteroids are generally safe, effective drugs, but adverse endocrine effects may occur. Although adverse effects and the thresholds defined as high dose by asthma guidelines do not precisely correlate, for the sake of clinical practice, high dose for any particular compound is similar to that defined by the National Asthma Education and Prevention Program.…”

Increasing burden of type 2 diabetes in Navajo youth: The SEARCH for diabetes in youth study

“…Over the study period, both provider awareness of YT2D and changes in diagnostic approaches could have influenced our findings. Specifically, the American Diabetes Association (ADA) included hemoglobin A1c (HbA1c) as one of the accepted diagnostic tests for diabetes in 2010 . Prior to this time, clinicians relied on some combination of random blood glucose, fasting blood glucose, and oral glucose tolerance testing (OGTT).…”

“…While these tests remain part of the clinical approach to diabetes screening and diagnosis, the addition of laboratory HbA1c has reduced perceived testing barriers. While there is some concern that HbA1c in children may have a lower sensitivity and yield fewer T2D cases, further analysis within other Southwest American Indian populations showed that HbA1c was predictive of future diabetes development . Trends in self‐reported YT2D case presentation (2002‐2010), specifically whether youth were identified due to having symptoms, as the result of a “checkup,” or due to community screenings, were previously evaluated by SEARCH .…”