Evaluation of a Novel Self-Sampling Earwax Tool for Chronic Disease Biomarkers [TREARS STUDIES II]

Title

The Validity of a Novel Diabetes Diagnostic Device and its Feasibility as Metabolic Syndrome Diagnostic One.

\[TREARS STUDIES II\] Herane-Vives, Andres1,2,3

1. Visiting Lecturer; Institute of Cognitive Neuroscience; Clinical, Educational \& Health Psychology Department; Faculty of Brain Disease; University College London Alexandra House; 17-19 Queen Square; Bloomsbury; London; UK. 2. Visiting Lecturer; Affective Disorders Research Group, Centre for Affective Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology \& Neuroscience, King's College London, London, UK. 3. Trears Biomarkers Ltd, Founder \& CEO, General Adult Psychiatrist Consultant, London, UK.

Abstract

Background: Long-term biomarker alterations feature chronic diseases. Metabolic Syndrome (MetS) is a cluster of them, i.e., diabetes, obesity, dyslipidaemia and high Blood Pressure (BP). Instead of genetic factors that could determine a categorical predisposition for this condition, MetS is primarily explained by the long-term effect of specific but dynamic lifestyles. Analysing MetS, as well as lifestyles, such as diet and physical activity, involves measuring long-term levels of many biomarkers. Because of their instant results, digital devices have been widely used for diagnosing MetS diseases, such as high BP, even though most can only record an "acute" level since, as with other chronic diseases, BP vary significantly over the short term. 24-hour sodium (Na+) could be used to reflect chronic blood pressure, considering its strong association with that variable at a population level. However, the "short-term" confounding effect of acute salt intake hinders its validity for reflecting chronic BP at the individual level. Otherwise, it would be more reliable than current devices, which are not only greatly affected by other "short-term" influences, such as acute stressors or "white coat" blood pressure but also time-consuming and impractical tests at a clinical level. Nonetheless, 24-h Na+ excretion showed that a more applied sample for accumulating Na+ should also be more effective at diagnosing this pandemic. A confounding role of "acute" salt intake over "chronic" Na+ levels could be avoided if the novel sample stored Na+ longer than urine. Trears Biomarkers' mission is to improve all chronic disease diagnoses. Trears device is the first self-sampling device for analysing earwax in the lab. It is an already patented medical device class I. Trears devices are as reliable as a popular clinical method (Reiner-Alexander syringe) for sampling earwax for analysis but more efficiently. Our previous Phase I study from TRL=6 to TRL=7/8 showed, when used, earwax was significantly better than gold-standard specimens, such as HbA1c from blood, for reflecting chronic levels of substances, which vary considerably over short-term, e.g., glucose. Trears devices can increase poor compliance among chronic patients, using annoying and time-consuming sampling methods, e.g. needles; reduce lab costs; and avoid stressful sampling methods that locally increase biomarkers' levels, which confuse their concentrations at a systemic level. Hypotheses: 1) It is expected that Trears device can improve glucose intolerance and diabetes diagnoses, and 2) it could also reflect other chronic disease biomarker concentrations, e.g. MetS ones, which are also variables over short-term, e.g., BP/Na+ and lipids such as cholesterol \[HDL-C/LDL-C\] and triglycerides \[TD\]. Objectives: This research will assess the sensibility and specificity of our device for diagnosing diabetes and glucose intolerance \[Phase II study from TRL=7/8 to TRL=9\], and 2\] and its validity \[new Phase I study from TRL=6 to TRL=7/8\] for reflecting the average concentration of other chronic diseases biomarkers, such as MetS ones over 1- and 3 months. Methods: As earwax concentration does not differ between ear sides, the Trears Studies will be a longitudinal case \[258\]-control \[258\] study of four visits-screening and baseline visits and two follow-ups, one and two months apart. Novelty: From patients' homes and with single use, the Trears device could become the gold-standard diagnostic tool for diabetes and many other chronic conditions through this new Trears "multiplex" device, which could support the future development of the Trears multiplex Point-Of-Care \[POC\] test. Trears multiplex devices might finally enable the implementation of proper, precise measures for chronic disease patients.

Word count Abstract: 546 Main body: 11600

Keywords: Trears; Earwax; Self-Sampling Test; Chronic Diseases; POC; Long-Term \& Continuous levels.

Background and Scientific and Technological Content

Trears Biomarkers aims to improve chronic disease diagnoses by measuring the long-term level of their diagnostic biomarkers using earwax samples, which patients themselves will take. This project covers two main areas:

Diagnostic, medical technology, and devices. Trears Biomarkers aims to continue validating its self-sampling device through its phase II study from TRL=7/8 to TRL=9, deep interviews, and health economic studies to confirm that the Trears device is the most reliable, affordable, and comfortable tool for screening, diagnosing, and following up different types of diabetes and glucose intolerance. The project will also test the device's stability under realistic mailing conditions, capitalising on earwax's bacteriostatic properties to support remote diagnostics.

Another focus of this project is developing another earwax self-sampling device, which can analyse many or "multiplex" chronic disease biomarkers. Trears Biomarkers market will move from the enormous but restricted diabetes testing market of 8.5 billion US dollars to enter the preventative health market constituted by healthy people, meaning soaring our original market size. That is why this project also aims to develop a single device (Trears Multiplex) which will accurately measure in the lab all biomarkers involved in a condition \[MetS\] featured by several comorbid chronic diseases, currently affecting between 20% and 30% of the US adult population \[Phase 1 study from TRL=6 to TRL=7/8\].

More than five years of work and solid scientific evidence support this revolutionary project, which ground-breaking aims to measure blood pressure using a single earwax sodium sample rather than a series of measurements done by unreliable sphygmomanometers or costly digital devices, e.g. Holter of BP.

To achieve these goals, this project includes:

A phase I \& II prospective case-control study: 90 = +/- 7 days and will have four visits:

Screening (Day=-/+ 7),

Baseline (Day= 0), and two

Follow-ups 1 and

2, separated from the baseline by one (Day= 30) and two months (Day= 90), respectively.

Health economic analyses of different glucose and BP measurement methods for the diagnosis of diabetes/glucose intolerance and high BP, such as those taken by

Clinicians: plasma/serum from venous blood using syringes \[Reference Test=4\] and BP using sphygmomanometers \[Reference Test=5\].

Self-sampling methods, such as

i.- POCs use finger pricks (lancets) to measure biomarkers in situ from capillary blood \[Reference Test=2\], ii.- Continuous Glucose Monitoring \[CGM\] also in-situ but from the interstitial tissue, \[Reference Test=3\], iii.- Holter of BP, as approached measure to Continuous BP Monitoring \[CBPM\] \[Reference Test=6\] iv.- Home BP Monitoring \[HBPM\], as a manner to avoid "white coat" BP \[Reference Test=7\] and, v.- The Trears device uses earwax samples. \[Reference Test=1\]

A qualitative analysis of those sampling methods through deep interviews among a group of family doctors \[GPs\] and patients with diabetes or glucose intolerance, including perceptions of self-sampling feasibility and preferences regarding home mailing of biological samples, and,

Assess the validity of the Trears device in measuring chronic levels of MetS biomarkers to see whether it is worth developing a future Trears Multiplex POC Test.

At screening, participants will complete a short questionnaire on regular earplug use to allow stratified analysis of earwax composition and biomarker retention.

At baseline, a sub-study will test sample stability for postal transport by comparing bilateral earwax samples: one processed on-site during the day and the other mailed by the participant for delayed analysis (1, 3, or 7 days).

Problem and Opportunity

Non-Communicable Diseases (NCD) or chronic diseases, such as diabetes mellitus and MetS, constitute real pandemics. According to the National Health Contest in Chile, 12.3% of people over 15 had diabetes in 2017 (MINSAL, 2017). These figures indicate that our country has the most considerable prevalence of diabetes in South America (IDF, 2014). More outrageous is the figure which shows that the prevalence of a milder grade of hyperglycaemia or glucose intolerance (individuals with Impaired Glucose Tolerance \[IGT\] and Impaired Fasting Glucose \[IFG\] or diabetes) among Chileans adults is 36.0% (Nieto-Martinez et al., 2023). Furthermore, most all NCDs are chronic diseases. This explains several of their characteristics, such as the fact that long-term systemic alterations in different substances feature them. Indeed, a sustained elevation in glucose levels is mandatory for having diabetes (American Diabetes Association \[ADA\], 2010). However, current measurements from "short-term" specimens, such as serum, have significant limitations in the assessment of the average concentration of glucose level. Glucose levels also vary significantly during the day. Day-to-day hassles during periods of stress (Dagogo-Jack, 2010), smoking (Frati et al., 1996), high BP (Modan et al., 1985), Body Mass Index (BMI) (Hiller et al., 1998) and physical activity (Allen et al., 2009) can affect glucose levels. Some glucose measurements, such as fasting and postprandial glucose levels, have been standardised to provide a predictable glucose concentration level.

A single glucose test still does not accurately reflect the average concentration of glucose, which is the required level to monitor the glycaemic profile in metabolic chronic disorders such as diabetes (Makris \& Spanou, 2011). These levels are usually found either below the mean, such as those seen when the Fasting Serum Glucose (FSG) level is taken, or below the average when Postprandial Serum Glucose (PSG) one is used (Peter et al., 2006). These blood samples need to be taken by clinicians, which increases their costs, apart from the fact that they can be associated with some side effects, such as local pain. Their analysis cost is high since these samples require specific transporting and storing conditions. A similar situation also ensues in another chronic disease, such as high BP. The devices used for measuring that variable only take a cross-sectional picture of it, a result that does not necessarily correlate with its chronic level, which is the biomarker needed for diagnosing this long-lasting condition. Furthermore, short-term levels of cholesterol and triglycerides, the other MetS biomarkers, also vary depending on caloric intake.

According to the World Economic Forum, treating chronic conditions such as diabetes and hypertension will cost 47 trillion dollars worldwide by 2030 (Gambert, 2024). In the U.S., 90% of health costs are associated with chronic conditions (CDC, 2024). Currently, the outcomes of these conditions could also be improved. Rather than being curative, available drugs are primarily symptomatic. Recent studies indicate that compared to those who engage in diet and physical activity, diabetic patients treated with hypoglycaemic drugs have poorer long-term outcomes, even though they may show lower Glycated Haemoglobin (HbA1c) levels (HC et al., 2008). This strongly suggests that medical interventions for chronic diseases need to have a sustained effect over time to be effective. Addit

• Correlation between earwax sodium concentration and chronic blood pressure [Time frame: Single sampling at baseline; blood pressure history from past 3 months]