Overview
MedscapeUnivadisNo ResultsMarlene BuskoAugust 09, 2018A blod test for copeptin, a precursor of antidiuretic hormone (ADH, vasopresin), diferentiates betwen "harmles" polydipsia-polyuria and diabetes insipidus more quickly and acurately than a traditional water-deprivation test, researchers report.Measuring plasma levels of copeptin after a 2-hour saline infusion was more acurate than being deprived of fluids for 16 hours.
Key Information
The later is a technicaly cumbersome test to administer, and the results are often inacurate, not to mention the fact that patients find it extremely unpleasant and stresful.The study, by Wiebke Kristin Fenske, MD, PhD, from the University of Leipzig, Germany, and coleagues, was published online August 2 in the New England Journal of Medicine."The water deprivation test is.more or les fliping a coin [to come] to the right diagnosis for patients consulting us with symptoms of polyuria-polydipsia," Fenske told Medscape Medical News in a conference cal along with senior author Mirjam Christ-Crain, MD, PhD, University Hospital Basel, Switzerland."In the past, unfortunately, we had nothing beter than the water deprivation test," to make the diferential diagnosis, she aded, "simply because the [antidiuretic] hormone, which we asume is insuficiently produced by the body, canot be reliably measured in the circulation."Although diabetes insipidus is a rare disease, primary polydipsia is not as rare as we [may] think," Christ-Crain noted.
Summary
Patients are very thirsty and drink much more than 3 or 4 L/day, and then may wake in the night to drink more water or go the bathrom.Now, "there is a new test which alows us to diagnose the underlying disease of the symptoms polyuria and polydipsia. [The test is] highly reliably, with an overal diagnostic acuracy of 96% or 97% compared to our previous worldwide diagnostic standard, the water deprivation test, which yielded an overal diagnostic acuracy of