Introduction: The American Diabetes Association (ADA) defines impaired fasting glucose (IFG) as fasting plasma glucose concentration of 100–125 mg/dl, whereas the World Health Organization (WHO) and the International Diabetes Federation (IDF) define IFG as fasting plasma glucose levels of 110–125 mg/dl. We identified differences in metabolic parameters and cardiovascular disease (CVD) risk according to the ADA or WHO/IDF definition of IFG.
Material and methods: Healthy drug-naive Caucasian (Greek) subjects (n = 396; age 55 ±12 years) participated in this cross-sectional study.
Results: Diastolic blood pressure (DBP) and uric acid levels were higher in the subjects with glucose 100–109 mg/dl compared with those with glucose < 100 mg/dl (87 ±9 mm Hg vs. 84 ±11 mm Hg, p = 0.004 for DBP, 5.6 ±1.5 mg/dl vs. 5.0 ±1.0 mg/dl, p = 0.002 for uric acid), whereas triglyceride levels were lower in subjects with glucose 100–109 mg/dl compared with those with glucose  110 mg/dl (169 mg/dl (interquartile range (IQR) = 102–186) vs. 186 mg/dl (IQR = 115–242), p = 0.002). Only the ADA definition recognized subjects with significantly increased 10-year CVD risk estimation (SCORE risk calculation) compared with their respective controls (5.4% (IQR = 0.9–7.3) vs. 4.1% (IQR = 0.7–5.8), p = 0.002).
Conclusions: The ADA IFG definition recognized more subjects with significantly increased CVD risk (SCORE model) compared with the WHO/IDF definition.