Deeg, Mark A.

Introduction Cognitive behavioural therapy for insomnia (CBT-I) is effective at treating chronic insomnia, yet in-person CBT-I can often be challenging to access. Prior studies have used technology to bridge barriers but have been unable to extensively assess the impact of the digital therapeutic on real-world patient experience and multidimensional outcomes. Among patients with insomnia, our aim is to determine the impact of a prescription digital therapeutic (PDT) (PEAR-003b, FDA-authorised as Somryst; herein called PDT) that provides mobile-delivered CBT-I on patient-reported outcomes (PROs) and healthcare utilisation. Methods and analysis We are conducting a pragmatically designed, prospective, multicentre randomised controlled trial that leverages Hugo, a unique patient-centred health data-aggregating platform for data collection and patient follow-up from Hugo Health. A total of 100 participants with insomnia from two health centres will be enrolled onto the Hugo Health platform, provided with a linked Fitbit (Inspire 2) to track activity and then randomised 1:1 to receive (or not) the PDT for mobile-delivered CBT-I (Somryst). The primary outcome is a change in the insomnia severity index score from baseline to 9-week postrandomisation. Secondary outcomes include healthcare utilisation, health utility scores and clinical outcomes; change in sleep outcomes as measured with sleep diaries and a change in individual PROs including depressive symptoms, daytime sleepiness, health status, stress and anxiety. For those allocated to the PDT, we will also assess engagement with the PDT. Ethics and dissemination The Institutional Review Boards at Yale University and the Mayo Clinic have approved the trial protocol. This trial will provide important data to patients, clinicians and policymakers about the impact of the PDT device delivering CBT-I on PROs, clinical outcomes and healthcare utilisation. Findings will be disseminated to participants, presented at professional meetings and published in peer-reviewed journals. Trial registration number NCT04909229 .

OBJECTIVE Standardized, reproducible, and feasible quantification of β-cell function (BCF) is necessary for the evaluation of interventions to improve insulin secretion and important for comparison across studies. We therefore characterized the responses to, and reproducibility of, standardized methods of in vivo BCF across different glucose tolerance states. RESEARCH DESIGN AND METHODS Participants classified as having normal glucose tolerance (NGT; n = 23), prediabetes (PDM; n = 17), and type 2 diabetes mellitus (T2DM; n = 22) underwent two standardized mixed-meal tolerance tests (MMTT) and two standardized arginine stimulation tests (AST) in a test-retest paradigm and one frequently sampled intravenous glucose tolerance test (FSIGT). RESULTS From the MMTT, insulin secretion in T2DM was >86% lower compared with NGT or PDM (P < 0.001). Insulin sensitivity (Si) decreased from NGT to PDM (∼50%) to T2DM (93% lower [P < 0.001]). In the AST, insulin secretory response to arginine at basal glucose and during hyperglycemia was lower in T2DM compared with NGT and PDM (>58%; all P < 0.001). FSIGT showed decreases in both insulin secretion and Si across populations (P < 0.001), although Si did not differ significantly between PDM and T2DM populations. Reproducibility was generally good for the MMTT, with intraclass correlation coefficients (ICCs) ranging from ∼0.3 to ∼0.8 depending on population and variable. Reproducibility for the AST was very good, with ICC values >0.8 across all variables and populations. CONCLUSIONS Standardized MMTT and AST provide reproducible and complementary measures of BCF with characteristics favorable for longitudinal interventional trials use.

GPI-PLD [glycosylphosphatidylinositol (GPI)-specific phospholipase D (PLD)] is a secreted mammalian enzyme that specifically cleaves GPI-anchored proteins. In addition, the enzyme has been shown to cleave GPI anchor intermediates in cell lysates. The biosynthesis of the GPI anchor is well characterized; however, the mechanisms by which the levels of GPI anchor intermediates are regulated are still unknown. To investigate whether GPI-PLD plays a role in this regulation, we isolated stable HeLa cells overexpressing the enzyme. GPI-PLD-HeLa (GPI-PLD-transfected HeLa) cells showed a 3-fold increase in intracellular GPI-PLD activity and drastically decreased the levels of GPI-anchored proteins when compared with untransfected HeLa controls. Intracellular cleavage of GPI-anchored proteins has been suggested to occur early in the secretory pathway and, in agreement with this proposal, GPI-PLD activity in GPI-PLD-HeLa cells was detected not only in the endoplasmic reticulum and Golgi apparatus, but also in the plasma membrane. The enzyme was also active in lipid rafts, membrane microdomains in which GPI-anchored proteins and GPI anchor intermediates are concentrated, indicating that intracellular GPI-PLD cleavage may also occur in this compartment. Pulse–chase paradigms revealed the turnover rate of the last intermediate of the GPI anchor pathway in GPI-PLD-HeLa cells to be accelerated compared with the controls. Furthermore, 1,10-phenanthroline, a GPI-PLD inhibitor, reversed this effect. Our studies demonstrated that GPI-PLD can cleave not only GPI-anchored proteins, but also GPI anchor intermediates intracellularly. This observation opens the possibility that GPI-PLD can influence the steady-state levels of GPI-anchored proteins by hydrolysing the anchor before and after its attachment to proteins.