Glucose tolerance status is a better predictor of diabetes and cardiovascular outcomes than metabolic syndrome: a prospective cohort study

To evaluate the importance of oral glucose tolerance test (OGTT) in predicting diabetes and cardiovascular disease in patients with and without Metabolic Syndrome from a population treated in a primary care unit. A prospective cohort study was conducted with subjects regularly attending the primary care unit of Hospital de Clínicas de Porto Alegre. Participants underwent a 75 g OGTT. Metabolic syndrome definition was based on the criteria of IDF/AHA/NHLBI-2010. Participants mean age was 61 ± 12 years (males: 38%; whites: 67%). Of the 148 subjects included, 127 (86%) were followed for 36 ± 14 months, 21 (14%) were lost. Subjects were classified into four groups based on baseline OGTT: 29% normal (n = 43), 28% impaired fasting glucose (IFG; n = 42), 26% impaired glucose tolerance (IGT; n = 38), and 17% diabetes (n = 25). Metabolic syndrome prevalence was lower in normal group (28%), intermediate in IFG (62%) and IGT (65%) groups, and higher among subjects with diabetes (92%; P