Are the Same Clinical Risk Factors Relevant for Incident Diabetes Defined by Treatment, Fasting Plasma Glucose, and HbA1c?

Abstract

OBJECTIVETo compare incidences and risk factors for diabetes using seven definitions, with combinations of pharmacological treatment, fasting plasma glucose (FPG) ≥7.0 mmol/L, and HbA1c ≥6.5%.RESEARCH DESIGN AND METHODSParticipants aged 30–65 years from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort were followed for 9 years.RESULTSMore men had incident diabetes as defined by FPG ≥7.0 mmol/L and/or treatment than by HbA1c ≥6.5% and/or treatment: 7.5% (140/1,867) and 5.3% (99/1,874), respectively (P < 0.009); for women incidences were similar: 3.2% (63/1,958) and 3.4% (66/1,954). Known risk factors predicted diabetes for almost all definitions. Among those with incident diabetes by FPG alone versus HbA1c alone, there were more men (78 vs. 35%), case patients were 8 years younger, and fewer were alcohol abstainers (12 vs. 35%) (all P < 0.005). A diabetes risk score discriminated well between those with and without incident diabetes for all definitions.CONCLUSIONSIn men, FPG definitions yielded more incident cases of diabetes than HbA1c definitions, in contrast with women. An FPG-derived risk score remained relevant for HbA1c-defined diabetes.

Fasting plasma glucose and HbA1c in cardiovascular risk prediction: a sex-specific comparison in individuals without diabetes mellitus

“…Nevertheless, individuals with IFG and those with HbA 1c -defined prediabetes showed a similarly increased burden of cardiovascular risk factors. In concordance with findings from a recently published study, the most important difference was that more men were classified with prediabetes by FPG than by HbA 1c [26]. Although most of the cardiovascular risk factors were statistically significantly increased in the prediabetes groups, the clinical importance of the differences was small when compared with the large differences observed between individuals with and without manifest diabetes mellitus.…”

Enhanced Predictive Capability of a 1-Hour Oral Glucose Tolerance Test: A Prospective Population-Based Cohort Study

“…The definition of type 2 diabetes has changed over the past decades, notably with the lowering of the fasting glucose threshold in 1997 and the introduction of HbA 1c -defined diabetes in 2011 (7). However, despite there being only a partial overlap between subjects with prediabetes and diabetes defined according to these different measures, the predictive capability of clinical risk factors remains comparable (7,39). The 30 g/m 2 glucose load was the standard procedure at the initiation of the study, and based on estimates of body surface area, this resulted in an average glucose load 23% lower than with the use of 75-g glucose.…”

Effects of diabetes definition on global surveillance of diabetes prevalence and diagnosis: a pooled analysis of 96 population-based studies with 331 288 participants

“…Some studies have analysed the classification of individuals as having diabetes or compared prevalence estimates based on different definitions in specific cohorts, especially for HbA 1c compared with either FPG or 2hOGTT. 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 Most of these analyses were based on a single cohort and very few covered different geographical regions. Two pooled analyses of Asian and European cohorts, and a study in the Pacific and Indian Ocean islands, assessed how the prevalence of diabetes and the classification of individuals as having diabetes versus not having diabetes changed depending on whether diabetes was defined by FPG or 2hOGTT.…”