Creating a pandemic of prediabetes: the proposed new diagnostic criteria for impaired fasting glycaemia

Abstract

Aims/hypothesis. In November 2003 the American Diabetes Association expert committee on the diagnosis and classification of diabetes mellitus suggested a revision of the diagnostic criteria for IFG, lowering the diagnostic threshold from 6.1 to 5.6 mmol/l. The aim of the present study was to evaluate the consequences of this change with respect to: (i) the prevalence of IFG in five different countries; (ii) the concordance between IFG and IGT (classification of individuals); and (iii) the cardiovascular risk profile of these groups. Finally we discuss the likelihood that intervention for cardiovascular risk and prevention strategies developed for individuals with IGT are applicable to subjects with IFG. Methods. The first part of the study is based on the population-based Danish Inter99 study, where 6265 individuals, aged 30 to 60 years and without previously diagnosed diabetes, underwent an oral glucose tolerance test. The second part is based on the DETECT-2 project, in which studies from China, India, France and USA were used to analyse the impact of the proposed revision of the diagnostic criteria in different ethnic groups. Results. The proposed change in diagnostic criteria would increase the prevalence of IFG in Denmark from 11.8 to 37.6%. The proposed IFG category would identify 60.0% of all subjects with IGT compared to 29.2% with the old criteria, but among individuals with the new IFG category only 18.5% would also have IGT. Individuals with isolated IFG had lower insulin levels and a lower cardiovascular risk profile with the proposed criteria compared with the current WHO criteria. Data from the DETECT-2 study confirmed the marked increase in the prevalence of IFG, and the estimated number of individuals in the age range 40 to 64 years with IFG in urban India, urban China and the USA would increase by 78%, 135% and 193% respectively. Conclusions/interpretation. The proposed revised diagnostic criteria will lead to a dramatic increase in the prevalence of IFG, but the concordance rate between IFG and IGT remains low. This new IFG group will have a more favourable cardiovascular risk profile than the current IFG group as defined by the WHO. This seriously questions whether the existing intervention strategies are applicable to the new category of individuals with IFG.

A report on the diagnosis of intermediate hyperglycemia in Korea: A pooled analysis of four community-based cohort studies

“…However, there are points to be considered when applying the new definition of IFG in Korea. BorchJohnsen et al emphasized that the new ADA criteria would lead to a dramatic increase in the prevalence of IFG and demonstrated a low concordance rate between IFG and IGT [29]. We also observed very poor agreement between the fasting and 2-h PG criteria with the new definition of IFG.…”

HbA1c, fasting plasma glucose and the prediction of diabetes: Inter99, AusDiab and D.E.S.I.R.

“…The lower limit of IFG was decreased in 2003 from 6.1 to 5.6 mmol/l by an ADA International Expert Committee [12]. While there are a number of studies that show there is an increased risk of diabetes for those with IGT and IFG [13], there has not been a search for more precise thresholds for these categories, nor for HbA1c. Indeed, the 2003 change in the definition of IFG has been disputed [14].…”

?to: Borch-Johnsen K, Colagiuri S, Balkau B et al. (2004) Creating a pandemic of prediabetes: the proposed new diagnostic criteria for impaired fasting glycaemia. Diabetologia 47:1396?1402

“…We read with interest the paper by BorchJohnsen and co-workers [1] on the impact of lowering the threshold for the diagnosis of IFG from 6.1 to 5.6 mmol/l, as recently proposed by the American Diabetes Association (ADA) expert committee on the diagnosis and classification of diabetes [2]. The authors point out a number of issues that need to be clarified, and we fully agree with their view that there is a need for extensive and thorough analysis of existing data in order to provide as much evidence as possible before proposing new criteria.…”