OBJECTIVE We compared the risk of cardiovascular disease (CVD) and all-cause mortality in subgroups of prediabetes defined by fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), or HbA1c. RESEARCH DESIGN AND METHODS In theWhitehall II cohort, 5,427 participants aged 50-79 years and without diabetes were followed for a median of 11.5 years. A total of 628 (11.6%) had prediabetes by theWorld Health Organization (WHO)/International Expert Committee (IEC) criteria (FPG 6.1-6.9 mmol/L and/or HbA1c 6.0-6.4%), and 1,996 (36.8%) by the American Diabetes Association (ADA) criteria (FPG 5.6-6.9 mmol/L and/or HbA1c 5.7-6.4%). In a subset of 4,730 individuals with additional measures of 2hPG, 663 (14.0%) had prediabetes by 2hPG. Incidence rates of a major event (nonfatal/fatal CVD or allcause mortality) were compared for different definitions of prediabetes, with adjustment for relevant confounders. RESULTS Compared with that for normoglycemia, incidence rate in the context of prediabetes was 54%higherwith theWHO/IEC definition and 37%higher with the ADA definition (P<0.001) but declining to 17% and 12% after confounder adjustment (P ≥ 0.111). Prediabetes by HbA1c was associated with a doubling in incidence rate for both the IEC and ADA criteria. However, upon adjustment, excess riskwas reduced to 13%and 17%(P ≥ 0.055), respectively. Prediabetes by FPGor 2hPGwas not associatedwith an excess risk in the adjusted analysis. CONCLUSIONS Prediabetes defined by HbA1c was associated with a worse prognosis than prediabetes defined by FPG or 2hPG. However, the excess risk among individuals with prediabetes is mainly explained by the clustering of other cardiometabolic risk factors associated with hyperglycemia.
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism
- Advanced and Specialised Nursing