Discordance in glycemic categories and regression to normality at baseline in 10,000 people in a Type 2 diabetes prevention trial

Abstract

The world diabetes population quadrupled between 1980 and 2014 to 422 million and the enormous impact of Type 2 diabetes is recognised by the recent creation of national Type 2 diabetes prevention programmes. There is uncertainty about how to correctly risk stratify people for entry into prevention programmes, how combinations of multiple ‘at high risk’ glycemic categories predict outcome, and how the large recently defined ‘at risk’ population based on an elevated glycosylated haemoglobin (HbA1c) should be managed. We identified all 141,973 people at highest risk of diabetes in our population, and screened 10,000 of these with paired fasting plasma glucose and HbA1c for randomisation into a very large Type 2 diabetes prevention trial. Baseline discordance rate between highest risk categories was 45.6%, and 21.3–37.0% of highest risk glycaemic categories regressed to normality between paired baseline measurements (median 40 days apart). Accurate risk stratification using both fasting plasma glucose and HbA1c data, the use of paired baseline data, and awareness of diagnostic imprecision at diagnostic thresholds would avoid substantial overestimation of the true risk of Type 2 diabetes and the potential benefits (or otherwise) of intervention, in high risk subjects entering prevention trials and programmes.

Lifestyle Intervention With or Without Lay Volunteers to Prevent Type 2 Diabetes in People With Impaired Fasting Glucose and/or Nondiabetic Hyperglycemia

“…57 The framework in which the NDPS DPM operated was also highly supportive and structured within a multidisciplinary diabetes prevention team, one of the more effective ways to use lay volunteers. 30,36 We do not think therefore that the the lack of effect our DPM model is due to low intensity DPM training, a short duration of intervention, or an unsupportive framework. 30,36 It is possible that more intensive contact from the DPM and higher frequency telephone contact may have been more effective.…”

“…30,36 We do not think therefore that the the lack of effect our DPM model is due to low intensity DPM training, a short duration of intervention, or an unsupportive framework. 30,36 It is possible that more intensive contact from the DPM and higher frequency telephone contact may have been more effective. 32,33,55,56 It is also quite possible that the lack of DPM effect could be due to the already large prevention effect size already attained with the standard intervention alone.…”

“…35 Participants with an eligible glycemic high risk category on initial testing had repeat testing a median 40 days (interquartile range 27 -69 days) later. 35,36 Trial randomization was offered if paired baseline tests were concordant for a high risk intermediate glycemic category. The first screening appointment was August, 22 nd , 2011 and last March , 24 th , 2017.…”

Determinants of diagnostic discordance for non‐diabetic hyperglycaemia and Type 2 diabetes using paired glycated haemoglobin measurements in a large English primary care population: cross‐sectional study

“…This study adds to our previous report by investigating the value of participant characteristics other than initial HbA 1c results in predicting whether individuals had discordant non‐diabetic hyperglycaemia and Type 2 diabetes diagnoses on retesting. The study showed that initial diagnosis of prediabetes according to both HbA 1c and FPG criteria made reclassification as normal less likely, and reclassification as Type 2 diabetes more likely, than initial classification according to HbA 1c alone.…”

Pre‐operative optimisation of the surgical patient with diagnosed and undiagnosed diabetes: a practical review

“…Pre‐diabetes is diagnosed by one of: a marginally elevated glycated haemoglobin (HbA1c) concentration; an impaired fasting glucose; impaired glucose tolerance. These diagnostic criteria for pre‐diabetes do not describe the same populations, but they do overlap . Depending on the organisation, the definitions are different.…”