Major Finding: An in-home urine test discriminated type 1 juvenile diabetes from maturity-onset diabetes of youth with 100% sensitivity and 85% specificity.
Data Source: A confirmatory study of 125 children, 96 of whom had been diagnosed with type 1 diabetes and 29 with MODY.
Disclosures: Dr. Besser had no financial disclosures.
LISBON – A single in-home test of urinary C-peptide creatinine ratio appears to differentiate type 1 diabetes from a genetic form of the disease – maturity-onset diabetes of youth.
The test saves children and parents from the stress and inconvenience of a blood test, and discriminates maturity-onset diabetes of youth (MODY) from type 1 diabetes with 100% sensitivity and 85% specificity, Dr. Rachel Besser said at the meeting.
“MODY is frequently misdiagnosed as type 1 diabetes in children, and inappropriately treated with insulin,” said Dr. Besser of Peninsula Medical School, Exeter (England). “This test is clinically useful even in patients with a very short duration of disease.”
In addition to guiding treatment, the test, which is a simple kit designed to be administered after a normal, diabetic-healthy evening meal, can pinpoint which children should undergo genetic testing for MODY, she said. “We ask the children to empty their bladders before eating, have a dinner that contains healthy carbohydrates, and then take the test about 2 hours later.”
Parents mail the sample to a laboratory where the urinary C-peptide creatinine ratio (UCPCR) is measured. A boric acid solution preserves the biomarker for up to 72 hours while en route to the lab.
Dr. Besser and her colleagues examined the test's efficacy in 96 children who had been diagnosed with type 1 diabetes and 29 children who had confirmed MODY (10 with the HNF1A/4A subtype and 19 with the GCK subtype). All of the children had a mean disease duration of 3 years. The mean age of the type 1 patients was 13 years; the MODY patients had a mean age of 14 years.
The test differentiated the two disorders quite well, Dr. Besser said. UCPCR was significantly lower in the type 1 samples than in the MODY samples (median 0.05 vs. 3.41 nmol/mmol). With the use of a cutoff of at least 1.4 nmol/mmol, the test correctly discriminated MODY from type 1 diabetes with 100% sensitivity and 85% specificity. Fourteen of the patients diagnosed with type 1 diabetes met the cutoff point of at least 1.4 nmol/mmol.