Seasonal and Regional Influences on Alcohol Consumption: An Analysis of Near-Real-Time Urine Drug Test Results in Those Seeking Health Care.

AIMS: To examine the probability of detecting alcohol via urine drug testing (UDT) as influenced by age, gender, seasonality, geography, COVID-19, and time in those seeking health care. METHODS: A cross-sectional study of UDT results from January 1, 2013, to December 31, 2020, was conducted using adult patient specimens submitted for testing by health care professionals as part of routine care. The UDT analysis used LC-MS/MS to detect two alcohol metabolites, ethyl glucuronide and ethyl sulfate. Seasonal adjustment of positivity rates was accomplished using the STL method; trend analysis was performed on seasonally adjusted rates. Logistic regression was used to associate demographic features, and an interaction term for collection year and U.S. census division was included to help understand the changing nature of alcohol use over time and across divisions. RESULTS: Alcohol positivity rate shows strong seasonal changes with an oscillating profile that peaks in the summer and is at a low point in winter. The highest predicted positivity rate for alcohol was in male patients, 45-64 years of age, and from a primary care setting. Alcohol positivity peaked in 2016 and declined the following year. While remaining relatively steady since 2017, a small but significant increase was noted after the COVID-19 emergency declaration on March 13, 2020. The probability of being alcohol-positive varies significantly by geographic region, and not all regions are changing at the same rate. CONCLUSIONS: Alcohol positivity in UDT in patients seeking health care is influenced by multiple factors and has increased during the COVID-19 pandemic.

Evaluation of a novel ELISA for serotonin: urinary serotonin as a potential biomarker for depression.

Depression is a common disorder with physical and psychological manifestations often associated with low serotonin. Since noninvasive diagnostic tools for depression are sparse, we evaluated the clinical utility of a novel ELISA for the measurement of serotonin in urine from depressed subjects and from subjects under antidepressant therapy. We developed a competitive ELISA for direct measurement of serotonin in derivatized urine samples. Assay performance was evaluated and applied to clinical samples. The analytical range of the assay was from 6.7 to 425 µg serotonin/g creatinine (Cr). The limit of quantification was 4.7 µg/g Cr. The average recovery for spiked urine samples was 104.4%. Average intra-assay variation was 4.4%, and inter-assay variation was <20%. The serotonin analysis was very specific. No significant interferences were observed for 44 structurally and nonstructurally related urinary substances. Very good correlation was observed between urinary serotonin levels measured by ELISA and liquid chromatography tandem mass spectrometry (LC-MS/MS; ELISA = 1.16 × LC-MS/MS - 53.8; r = 0.965; mean % bias = 11%; n = 18). Serotonin was stable in acidified urine for 30 days at room temperature and at -20 °C. The established reference range for serotonin was 54-366 µg/g Cr (n = 64). Serotonin levels detected in depressed patients (87.53 ± 4.89 µg/g Cr; n = 60) were significantly lower (p < 0.001) than in nondepressed subjects (153.38 ± 7.99 µg/g Cr). Urinary excretion of serotonin in depressed individuals significantly increased after antidepressant treatment by 5-hydroxy-tryptophane and/or selective serotonin re-uptake inhibitor (p < 0.01). The present ELISA provides a convenient and robust method for monitoring urinary serotonin. It is suitable to monitor serotonin imbalances and may be particularly helpful in evaluating antidepressant therapies.

Neurotransmitters excreted in the urine as biomarkers of nervous system activity: validity and clinical applicability.

Strategies for managing the nervous system are numerous while methods of evaluating the nervous system are limited. Given the physiological importance of neurotransmitters as signaling molecules in the nervous system, the measurement of neurotransmitters has significant potential as a clinical tool. Of all the biological fluids that can be utilized, urinary neurotransmitter testing, due to its stability, sensitivity, and non-invasiveness, is the desired method to analyze nervous system function. Increasing use of this technology in a clinical setting demands a review of its feasibility, utility, and clinical value. We review the current body of literature pertaining to the mechanism of neurotransmitter transport across the blood-brain barrier as well as neurotransmitter filtration and excretion by the kidneys. In addition, this review summarizes the historical use of urinary neurotransmitter assessment to diagnose pheochromocytoma. Early research also correlated urinary assessment of neurotransmitters to various clinical symptoms and treatments of which we present research only for depression, ADHD, and inflammation because of the abundant amount of research in these areas. Finally, we review the limitations and challenges of urinary neurotransmitter testing. Taken together, evidence suggests that neurotransmitters excreted in the urine may have a place in clinical practice as a biomarker of nervous system function to effectively assess disturbances and monitor treatment efficacy.