[Glycosylated hemoglobin A1c as a diagnostic test for diabetes mellitus in adolescents with overweight and obesity].
BACKGROUND
In 2009 it was introduced a new diagnostic criteria based on hemoglobin A1c (HbA1c) greater than or equal to 6.5 % in the adult population; some studies suggest that the cutoff may be smaller in pediatric population. The objective was to determine the utility of HbA1c greater than or equal to 6.5 % as a diagnostic test for DM in Mexican adolescents with overweight or obesity.


METHODS
Full somatometry was performed. Also, Tanner stage, blood pressure, blood glucose, glucose tolerance curve (GTC) and HbA1c were analyzed. Specificity, sensitivity, positive and negative predictive values and ROC curve were calculated for the diagnosis of DM with HbA1c.


RESULTS
109 adolescents between 10 and 16 years referred for obesity or overweight plus comorbidities were studied; 58 % were females, the age was of 13 ± 1.74 years, the BMI percentile 95.3, and the HbA1c 5.73 ± 0.9 %. It was made a diagnosis of DM in 9 cases (8.3 %), prediabetes in 8 (7.3 %) and normal glucose tolerance in 92 (84.4 %). The HbA1c mean was 5.6 ± 0.04, 5.7 ± 0.4, and 5.6 ± 0.73 %, respectively. HbA1c greater than or equal to 6.5 % had a sensitivity of 12.5 %, a specificity of 89.8 %, a PPV of 10.65 and a NPV of 14.28. The best cutoff point for diagnosing DM through ROC curve was 5.45 %, with a sensitivity of 62.5 %, a specificity of 57.1 %, PPV 2.53 and NPV 33.3.


CONCLUSIONS
The level of HbA1c greater than or equal to 6.5 % had low sensitivity and specificity for the diagnosis of DM. A lower cutoff point is insufficient to use HbA1c as a diagnostic criterion. These results are consistent with the ones of other journals.
Servicio de Endocrinología, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Distrito Federal, México. riha0306@hotmail.com.
Aleida
A
Rivera-Hernández
Jessie Nallely
JN
Zurita-Cruz
Eulalia
E
Garrido-Magaña
Gigliola Margaretta
GM
Fiorentini-Fayad
Elisa
E
Nishimura-Meguro
D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D002648:Child; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008800:Mexico; D050177:Overweight / Q000150:complications; D063766:Pediatric Obesity / Q000150:complications*; D012372:ROC Curve; D012680:Sensitivity and Specificity
D015415:Biomarkers; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
Adolescent; Child; Glycosylated hemoglobin A