What are the guidelines for screening for diabetes mellitus (DM) in adolescents?

From the Guidelines

Testing for diabetes in adolescents should be considered after the onset of puberty or at 10 years of age, whichever occurs earlier, in youth with overweight or obesity and one or more additional risk factors for diabetes. This approach is based on the latest recommendations from the American Diabetes Association, as outlined in the 2025 standards of care in diabetes 1. The rationale behind this recommendation is to identify individuals at high risk of developing type 2 diabetes, which has been increasingly prevalent in adolescents due to the rising obesity rates.

Risk Factors and Screening

Key risk factors for type 2 diabetes in adolescents include:

• Overweight or obesity (BMI ≥85th percentile)
• Family history of diabetes
• Certain ethnicities (e.g., Native American, African American, Latino, Asian American, Pacific Islander)
• Presence of other conditions like polycystic ovary syndrome For asymptomatic adolescents with these risk factors, screening should be performed using one of the following tests:
• Fasting plasma glucose
• 2-hour plasma glucose during a 75-g oral glucose tolerance test
• A1C If the initial screening is normal, it should be repeated at a minimum of 2-year intervals or more frequently if the BMI is increasing 1.

Importance of Early Detection

Early detection of diabetes in adolescents is crucial because they can develop complications quickly, and type 2 diabetes is increasingly common in this age group due to rising obesity rates. Proper diagnosis allows for timely intervention with lifestyle modifications, education, and medication if necessary. The presence of diabetes-associated autoantibodies should also be tested to exclude the possibility of autoimmune type 1 diabetes in children and adolescents with overweight or obesity in whom the diagnosis of type 2 diabetes is being considered 1.

Testing and Diagnosis

For adolescents with symptoms suggestive of diabetes, such as increased thirst, frequent urination, unexplained weight loss, or fatigue, immediate testing is warranted. The primary test is a fasting plasma glucose test, with values ≥126 mg/dL (7.0 mmol/L) indicating diabetes. Alternative tests include a random plasma glucose test (≥200 mg/dL with symptoms), an oral glucose tolerance test (2-hour plasma glucose ≥200 mg/dL), or hemoglobin A1C (≥6.5%) 1.

Management and Follow-Up

Given the unique features of type 2 diabetes in youth, including a more rapid decline in beta-cell function and accelerated development of diabetes complications, close communication with school personnel is essential for optimal diabetes management and safety, as well as maximal academic opportunities. Long-term follow-up data from studies like the TODAY study highlight the importance of early intervention and sustained management to prevent or delay the onset of microvascular complications in young adulthood 1.

From the Research

Diagnostic Tests for Diabetes in Adolescents

• The most commonly used diagnostic tests for diabetes in adolescents are fasting plasma glucose (FPG), oral glucose tolerance test (OGTT), and glycated hemoglobin A1c (HbA1c) 2.
• Each test has its advantages and disadvantages, and none of them have been validated in the pediatric population 2.
• OGTT is considered the most sensitive test for detecting impaired glucose tolerance, but it has low reproducibility and is inconvenient 2.
• FPG measurement is more practical, but it requires fasting and may not detect all cases of diabetes 2.
• HbA1c is a convenient test, but its reliability as a screening tool has been questioned, especially in children and adolescents 2, 3.

Screening Practices for Diabetes in Adolescents

• A study found that pediatricians and family physicians often use HbA1c as a screening test for diabetes in adolescents, despite its limitations 4.
• The American Diabetes Association recommends using HbA1c as a screening test for diabetes, but its use in adolescents is still a topic of debate 4, 3.
• Another study found that HbA1c is a poorer predictor of diabetes in adolescents compared to adults, and its use as a diagnostic tool may be premature 3.

Performance of Diagnostic Tests in Adolescents

• A study found that HbA1c had low sensitivity and specificity for detecting diabetes in adolescents, and its performance was poor regardless of whether FPG or 2-hour plasma glucose measurements were used 3.
• Another study found that HbA1c was a specific and useful non-fasting test for identifying high-risk youth who could benefit from lifestyle interventions to prevent diabetes and cardiovascular risk in adulthood 5.
• The oral glucose tolerance test (OGTT) is still considered a valid test for diagnosing diabetes, and its use in combination with FPG and HbA1c can improve diagnostic accuracy 6.

Recommendations for Diagnostic Testing in Adolescents

• The optimal approach to screening and diagnosis of prediabetes and diabetes in youth is uncertain, and more research is needed to determine the best diagnostic tests and criteria for adolescents 5.
• A study suggests that performing additional OGTT for patients with FPG ≥110 mg/dL or HbA1c ≥6.1% can be helpful to reclassify their glucose tolerance status and evaluate their potential for progressing to overt diabetes 6.
• Healthcare providers should consider the advantages and disadvantages of each diagnostic test, as well as the possibility of performing different tests at once, when choosing the most suitable test for adolescents 2.