A systematic review of the association between urinary biomarkers and pain

Abstract

There are many clinical situations where it is not possible to be certain if a patient is experiencing pain. A urinary biomarker of pain would expedite diagnosis and treatment. The collection of urine is non-invasive, which makes it an ideal choice in situations where patients are stressed and already suffering pain. This systematic review aims to determine if there is a urinary biomarker that has consistently been associated with changing levels of pain, and may reflect underlying biological mechanisms associated with the production of pain. Materials and Methods A literature search was conducted of Embase, Medline, PubMed, Web of Science, and Scopus using the search keywords urine, biomarker and pain. There were no limitations on publication dates. The search was limited to English language and human studies. Results 1251 articles were screened. 833 were eliminated by title or abstract as not fulfilling the search criteria. After elimination of duplicates, 277 studies were identified as uniquely fulfilling the search characteristics composed of 22 randomized controlled trials (RCTs), 44 controlled observational studies, and 211 case studies or series. In order to fulfill the selection criteria, the 22 RCTs had to include both pain and urinary measurements as outcomes in the abstract of the article. The RCTS involved 2177 patients with varied pain conditions and urinary biomarkers. Discussion The research involving urinary biomarkers in painful conditions of bone turnover have found statistically significant correlations between disease progression and pain. The biomarkers chosen may reflect the mechanism of the disorder rather than pain. Conclusion High quality long duration RCTs using interventions with proven efficacy are required to investigate the association between urinary biomarkers and pain.