Publications by authors named "John M Dennis"

Aims: To assess outcomes of oral anti-hyperglycaemic therapies in people with diabetes secondary to a pancreatic condition (type 3c), where specific treatment guidance is limited.

Materials And Methods: Using hospital-linked UK primary care records (Clinical Practice Research Datalink; 2004-2020), we identified 7084 people with a pancreatic condition (acute pancreatitis, chronic pancreatitis, pancreatic cancer and haemochromatosis) preceding diabetes diagnosis (type 3c cohort), initiating oral glucose-lowering therapy (metformin, sulphonylureas, SGLT2-inhibitors, DPP4-inhibitors or thiazolidinediones), and without concurrent insulin treatment. We stratified by pancreatic exocrine insufficiency [PEI] (n = 5917 without PEI, 1167 with PEI) and matched to 97 227 type 2 diabetes (T2D) controls.

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Article Synopsis
  • - Precision medicine aims to enhance the accuracy and reliability of health recommendations while ensuring safety and cost-effectiveness, but faces challenges due to the diverse nature of diseases and the lack of standardized reporting in research.
  • - The BePRECISE consortium, made up of 23 experts, developed a 23-item checklist to improve the reporting of precision medicine research, using a thorough review process to create guidelines.
  • - The checklist promotes inclusivity in research by emphasizing health equity, encouraging the involvement of under-represented communities, which can help with the effective and fair application of precision medicine in clinical settings.
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Aims/hypothesis: Older adults are under-represented in trials, meaning the benefits and risks of glucose-lowering agents in this age group are unclear. The aim of this study was to assess the safety and effectiveness of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in people with type 2 diabetes aged over 70 years using causal analysis.

Methods: Hospital-linked UK primary care data (Clinical Practice Research Datalink, 2013-2020) were used to compare adverse events and effectiveness in individuals initiating SGLT2i compared with dipeptidyl peptidase-4 inhibitors (DPP4i).

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Aims/hypothesis: A precision medicine approach in type 2 diabetes could enhance targeting specific glucose-lowering therapies to individual patients most likely to benefit. We aimed to use the recently developed Bayesian causal forest (BCF) method to develop and validate an individualised treatment selection algorithm for two major type 2 diabetes drug classes, sodium-glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP1-RA).

Methods: We designed a predictive algorithm using BCF to estimate individual-level conditional average treatment effects for 12-month glycaemic outcome (HbA) between SGLT2i and GLP1-RA, based on routine clinical features of 46,394 people with type 2 diabetes in primary care in England (Clinical Practice Research Datalink; 27,319 for model development, 19,075 for hold-out validation), with additional external validation in 2252 people with type 2 diabetes from Scotland (SCI-Diabetes [Tayside & Fife]).

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Objective: This study aimed to compare clinical and sociodemographic risk factors for severe COVID-19, influenza and pneumonia, in people with diabetes.

Design: Population-based cohort study.

Setting: UK primary care records (Clinical Practice Research Datalink) linked to mortality and hospital records.

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Background: The handling of missing data is a challenge for inference and regression modelling. A particular challenge is dealing with missing predictor information, particularly when trying to build and make predictions from models for use in clinical practice.

Methods: We utilise a flexible Bayesian approach for handling missing predictor information in regression models.

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Recent type 2 diabetes guidance from the UK's National Institute for Health and Care Excellence (NICE) proposes offering SGLT2-inhibitor therapy to people with established atherosclerotic cardiovascular disease (ASCVD) or heart failure, and considering SGLT2-inhibitor therapy for those at high-risk of cardiovascular disease defined as a 10-year cardiovascular risk of > 10% using the QRISK2 algorithm. We used a contemporary population-representative UK cohort of people with type 2 diabetes to assess the implications of this guidance. 93.

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Article Synopsis
  • Precision medicine is an evolving approach in healthcare that aims to enhance decision-making and health outcomes, particularly in managing diabetes, which poses serious health risks for millions globally.
  • The second international consensus report on precision diabetes medicine reviews current findings on prevention, diagnosis, treatment, and prognosis across different forms of diabetes, highlighting the potential for translating research into clinical practice.
  • The report also identifies knowledge gaps and sets out key milestones for better clinical implementation, emphasizing the need for standards addressing cost-effectiveness, health equity, and accessibility in treatment options.
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Article Synopsis
  • A systematic review was conducted to explore the relationship between clinical and biological features and the effectiveness of two diabetes treatments: SGLT2-inhibitors and GLP1-receptor agonists, focusing on outcomes like glycaemic control, cardiovascular health, and kidney function.
  • Out of over 5,600 studies screened, only 101 for SGLT2-inhibitors and 75 for GLP1-receptor agonists were included, but many had methodological flaws that limited their reliability in assessing how different patients react to these treatments.
  • Findings suggest that factors like lower kidney function and reduced insulin secretion could affect treatment responses, but overall evidence is weak; further well-designed studies are needed to better understand treatment diversity and enhance
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Objective: Precision medicine requires reliable identification of variation in patient-level outcomes with different available treatments, often termed treatment effect heterogeneity. We aimed to evaluate the comparative utility of individualized treatment selection strategies based on predicted individual-level treatment effects from a causal forest machine learning algorithm and a penalized regression model.

Methods: Cohort study characterizing individual-level glucose-lowering response (6 month reduction in HbA1c) in people with type 2 diabetes initiating SGLT2-inhibitor or DPP4-inhibitor therapy.

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Background: A precision medicine approach in type 2 diabetes requires identification of clinical and biological features that are reproducibly associated with differences in clinical outcomes with specific anti-hyperglycaemic therapies. Robust evidence of such treatment effect heterogeneity could support more individualized clinical decisions on optimal type 2 diabetes therapy.

Methods: We performed a pre-registered systematic review of meta-analysis studies, randomized control trials, and observational studies evaluating clinical and biological features associated with heterogenous treatment effects for SGLT2-inhibitor and GLP1-receptor agonist therapies, considering glycaemic, cardiovascular, and renal outcomes.

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Precision medicine aims to treat an individual based on their clinical characteristics. A differential drug response, critical to using these features for therapy selection, has never been examined directly in type 2 diabetes. In this study, we tested two hypotheses: (1) individuals with body mass index (BMI) > 30 kg/m, compared to BMI ≤ 30 kg/m, have greater glucose lowering with thiazolidinediones than with DPP4 inhibitors, and (2) individuals with estimated glomerular filtration rate (eGFR) 60-90 ml/min/1.

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Background: Current treatment guidelines do not provide recommendations to support the selection of treatment for most people with type 2 diabetes. We aimed to develop and validate an algorithm to allow selection of optimal treatment based on glycaemic response, weight change, and tolerability outcomes when choosing between SGLT2 inhibitor or DPP-4 inhibitor therapies.

Methods: In this retrospective cohort study, we identified patients initiating SGLT2 and DPP-4 inhibitor therapies after Jan 1, 2013, from the UK Clinical Practice Research Datalink (CPRD).

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Aims/hypothesis: Screening programmes can detect cases of undiagnosed diabetes earlier than symptomatic or incidental diagnosis. However, the improvement in time to diagnosis achieved by screening programmes compared with routine clinical care is unclear. We aimed to use the UK Biobank population-based study to provide the first population-based estimate of the reduction in time to diabetes diagnosis that could be achieved by HbA-based screening in middle-aged adults.

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Type 2 diabetes (T2D) is a complex chronic disease characterized by considerable phenotypic heterogeneity. In this study, we applied a reverse graph embedding method to routinely collected data from 23,137 Scottish patients with newly diagnosed diabetes to visualize this heterogeneity and used partitioned diabetes polygenic risk scores to gain insight into the underlying biological processes. Overlaying risk of progression to outcomes of insulin requirement, chronic kidney disease, referable diabetic retinopathy and major adverse cardiovascular events, we show how these risks differ by patient phenotype.

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Background: The literature paints a complex picture of the association between mortality risk and ICU strain. In this study, we sought to determine if there is an association between mortality risk in intensive care units (ICU) and occupancy of beds compatible with mechanical ventilation, as a proxy for strain.

Methods: A national retrospective observational cohort study of 89 English hospital trusts (i.

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Background: Type 2 diabetes (T2D) is common and increasing in prevalence. It is possible to prevent or delay T2D using lifestyle intervention programmes. Entry to these programmes is usually determined by a measure of glycaemia in the 'intermediate' range.

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Objectives: To describe the relationship between reported serious operational problems (SOPs), and mortality for patients with COVID-19 admitted to intensive care units (ICUs).

Design: English national retrospective cohort study.

Setting: 89 English hospital trusts (i.

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Aims/hypothesis: Among white European children developing type 1 diabetes, the otherwise common HLA haplotype DR15-DQ6 is rare, and highly protective. Adult-onset type 1 diabetes is now known to represent more overall cases than childhood onset, but it is not known whether DR15-DQ6 is protective in older-adult-onset type 1 diabetes. We sought to quantify DR15-DQ6 protection against type 1 diabetes as age of onset increased.

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