Single Blood Sample Test May Help ID Undiagnosed Diabetes
(HealthDay News) — Single-sample confirmatory testing for diabetes has a high positive predictive value for subsequent diagnosis, according to a study published online June 19 in the Annals of Internal Medicine.
Elizabeth Selvin, Ph.D., M.P.H., from the Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues examined the prognostic performance of a single-sample confirmatory definition of undiagnosed diabetes among 12,268 participants in the Atherosclerosis Risk in Communities study without diagnosed diabetes at baseline and with 25 years of follow-up for incident diabetes, cardiovascular outcomes, kidney disease, and mortality.
The researchers found that 978 participants had elevated levels of fasting glucose or HbA1c at baseline and that, of these, 39 percent had both measures elevated (confirmed undiagnosed diabetes), while 61 percent had only one elevated measure (unconfirmed undiagnosed diabetes). For identification of diabetes cases diagnosed during the first five years of follow-up, the confirmatory definition had moderate sensitivity (54.9 percent) but high specificity (98.1 percent), which increased to 99.6 percent by 15 years. The 15-year positive predictive value was 88.7 percent versus 71.1 percent for unconfirmed cases.
"Our results support the clinical utility of using a combination of elevated fasting glucose and HbA1c levels from a single blood sample to identify undiagnosed diabetes in the population," the authors write.
One author disclosed financial ties to the biotechnology industry.