Early detection and timely and appropriate management of type 2 diabetes (T2D) are still suboptimal worldwide. In England, nearly one million individuals have undiagnosed T2D, corresponding to 25% of all cases. Furthermore, diabetes-related complications are often already present at the time of diagnosis. It has been estimated that 19% of the individuals with newly diagnosed T2D in England have already developed retinopathy, a diabetes-related complication affecting the eye, at the time of diagnosis. As part of preventive strategies to reduce the burden of T2D, in the recent years there has been an increasing focus in England on detection of non-diabetic hyperglycaemia (NDH). Individuals with NDH have elevated blood glucose levels just below the cut-point for a diagnosis of T2D and are considered at increased risk of developing T2D. However, little is known about whether the increasing focus on detection and early management of NDH prior to the diagnosis of T2D has an impact on improving health outcomes for individuals with T2D. The study aims to assess whether the detection and early management of NDH improves detection of T2D without its complications being present at diagnosis, and reduces the risk of mortality.
This is a retrospective open cohort study of adults diagnosed with T2D between Jan 2004 and Sept 2017 and registered with CPRD practices in England. The study aims to characterise the detection of non-diabetic hyperglycaemia (NDH) in primary care settings in England. It also aims to assess whether the detection of NDH prior to the diagnosis of T2D reduced the risk of the detection of microvascular and macrovascular complications at diagnosis of T2D, and all-cause and CVD mortality. CPRD data will be linked to ONS and mortality data to improve detection of the outcomes. Individuals will enter the cohort at time of the T2D diagnosis and followed-up until the end of the study period. Inverse probability weighting regression adjustment methods will be employed to model the probability of having a diabetes-related complication present at time of diagnosis or following a diagnosis of T2D as well as to model differences in rates of cardiovascular disease and all-cause mortality. The models will account for the probability of being tested and detected with NDH prior to the diagnosis of T2D (exposure variable) and will be controlled for individual and general practice characteristics associated with testing and disease progression.
Diagnosis of Retinopathy
Diagnosis of Acute Coronary disease
Cardiovascular risk factors (e.g. BMI, blood pressure)
Diagnosis of Nephropathy
Diagnosis of Peripheral Arterial Disease
Prescription of anti-diabetic medications
Diagnosis of Cerebrovascular disease
Cardiovascular disease and all-cause mortality
Christopher Millett - Chief Investigator - Imperial College London
Raffaele Palladino - Corresponding Applicant - Imperial College London
Eszter P Vamos - Collaborator - Imperial College London
Kiara Chang - Collaborator - Imperial College London
Mahsa Mazidi - Collaborator - Imperial College London
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation