NEW YORK — Early diabetes complications were seen in a significant proportion of 821 adolescents with type 1 diabetes for just 2-5 years.
Up to 1 in 5 of the adolescents had early indicators of eye, kidney, and/or nerve complications. The findings support early screening for diabetes complications as recommended by some—but not all—published consensus guidelines, Dr. Yoon Hi Cho said at a joint meeting of the Lawson Wilkins Pediatric Endocrine Society and the European Society for Pediatric Endocrinology.
The 821 patients were all seen at the Children's Hospital at Westmead, Sydney, between 1990 and 2006. They were aged 11-17 years, with a type 1 diabetes duration of 2-5 years (median 3.8) and a median hemoglobin A1c level of 8.9%.
Early retinopathy, defined as one microaneurysm or hemorrhage on seven-field stereoscopic fundus photography, was detected in 9% of the patients. Albumin excretion rate (AER) was measured for overnight urine collections. Early nephropathy, defined as a borderline elevation of AER of 7.5 to less than 20 mcg/min, was seen in 22% of the adolescents. Microalbuminuria, defined as an AER of 20 mcg/min or greater, was identified in 3%. Peripheral nerve abnormalities on thermal and vibration thresholds at the feet—measured by thermal threshold tester and biothesiometer—were found in 22% of the patients, said Dr. Cho, a clinical endocrinology fellow at the hospital.
The proportions with borderline AER elevation rose from 16% of those aged 11-13 years to 23% of 13- to 15-year-olds to 25% of those aged 15-17 years. There was no significant effect of age for retinopathy (seen in 6%, 10%, and 11% of the three groups) or for peripheral nerve abnormalities (seen in 27%, 19%, and 22%). The rates of microalbuminuria remained low (4% or below). There was no significant difference in hemoglobin A1c level between the three age groups (8.2%, 8.5%, and 8.6%), Dr. Cho said.
Retinopathy was significantly related to an elevated diastolic blood pressure level. A mean AER of 7.5 mcg/min or greater was associated with increased age, diabetes duration, and systolic BP. Peripheral nerve abnormalities were correlated with a higher BMI. There was no significant relationship between any of the complications and hemoglobin A1c level, cholesterol level, sex, insulin dose, or insulin regimen, she said.
Guidelines from the International Society for Pediatric and Adolescent Diabetes and from the Australian Pediatric Endocrinology Group both advise screening children for diabetes complications after a diabetes duration of 5 years in prepubertal children and after 2 years in adolescents. The American Diabetes Association recommends retinopathy screening within 5 years of the onset of diabetes and nephropathy screening after a diabetes duration of 5 years in children aged 10 years and older.
“Longitudinal analysis will help define predictors of early complications and the potential for modifying [their] natural history,” said Dr. Cho, who had no relevant financial disclosures.