Home / An exploratory pilot study with copeptin as a biomarker for individualizing treatment for nocturnal polyuria
Publication: Lower Urinary Tract Symptoms 2017 Oct 23
One of the primary causes of nocturnal polyuria (NP) is the disruption in the circadian rhythm of antidiuretic hormone (ADH), and substitution of low nocturnal ADH with desmopressin represents a valuable treatment of NP. In this context, ADH could be an important marker for the diagnosis of NP, but the small molecular size and short half-life preclude its analysis in clinical pratice.
In a retrospective analysis of an observational study performed at Ghent University Hospital between October 2011 and May 2013, the Authors investigated the relationship between copeptin, a peptide derived from the precursor of vasopressin, and NP in an adult population, in which it was expected to detect lower values in subjects with an impaired vasopressin circadian rhythm.
One-hundred eleven subjects with and without nocturia were included in the study and divided into 3 groups: controls (n= 51), those with NP (= 41), and those with global polyuria (= 19). Patients completed the male or female version of the International Consultation on Incontinence Modular Questionnaire on Lower Urinary Tract Symptoms (ICIQ-M-LUTS or ICIQ-F-LUTS, respectively) and a 72-hour frequency volume chart (FVC). A Renal Function Profile was recorded separately from the FVC. As results, copeptin concentrations were significantly lower in subjects with global polyuria than in those with NP, or the control group. In contrast, no significant difference in copeptin concentrations were observed between patients with NP and subjects in the control group, although these results showed variations depending on the definition of NP used.
The hypothesis that patients with NP have lower copeptin concentrations was not confirmed by the Authors; nevertheless the present article is the first exploring the relationship between copeptin and NP. Many researches on copeptin have focused on its potential role as a biomarker in severe diseases, such as sepsis, heart failure, and myocardial infarction, all conditions in which vasopressin is released due to severe body stress in an attempt to restore vascular tone and filling status. The Authors argued that further studies are needed to determine the best conditions and the best time (morning, evening) to investigate copeptin concentrations in a nocturia population, and the associations between copeptin concentrations and FVC and renal function profile.