An At Home Dried Saliva Spot (DSS) Test to Determine Insulin Resistance: A Scalable Tool for Early Detection in Underserved Communities

About This Grant

Project Summary/Abstract Type 2 diabetes mellitus (T2DM) is a major public health crisis in the United States, with disproportionately high incidence and worse outcomes in underserved and rural communities. Insulin resistance (IR) is the earliest clinical marker of T2DM risk, often preceding diagnosis by years, providing a crucial window for preventive interventions. Despite its significance, IR screening is underutilized due to reliance on blood-based assays that require phlebotomy and centralized laboratory infrastructure—barriers that disproportionately affect low-resource settings. This Phase I SBIR project addresses this gap by validating and refining a novel dried saliva spot (DSS) assay for fasting insulin and glucose measurement to calculate HOMA-IR, enabling home-based, low-cost screening for IR. Preliminary work demonstrates that DSS-derived fasting insulin and glucose levels correlate well with plasma-based values and are stable during mailing, even without cold-chain requirements. DSS samples are minimally invasive, self-collectable at home, and can be mailed directly to a centralized laboratory for analysis, bypassing the logistical and psychological challenges of blood-based testing. We will achieve our objectives through three specific aims: (1) Validate DSS-derived HOMA-IR against gold- standard plasma-based testing in a cohort of 300 adults representing diverse metabolic risk categories; (2) Evaluate the feasibility and acceptability of DSS home testing in a subset of 50 individuals; and (3) Assess the generalizability of DSS testing in broader underserved communities by deploying 100 home-collection kits in partnership with community organizations in rural and urban settings. Successful completion of this project will demonstrate the technical feasibility, user acceptability, and clinical validity of DSS-based IR testing. This work will enable scalable, equitable metabolic health assessments in underserved communities, support early disease interception, and lay the foundation for a Phase II trial focused on large-scale deployment and integration with community health programs.