Evolution of prediabetes in an urban cohort of adults living in a Mediterranean area

Background: Prediabetes (PD) precedes type 2 diabetes (T2D), it can be easily recognized by fasting plasma glucose concentrations (FPG) or HbA1c or 2 h post glucose load glycemia, thereby enabling prevention strategies. We investigated the progression of PD to T2D in the ABCD study (Alimentazione, Benessere Cardiovascolare e Diabete -ISRCTN15840340) that included a representative cohort of adult people living in the Mediterranean area of Palermo (Italy). Materials and methods: The ABCD cohort was enrolled in 2011 and re-evaluated in 2015. The FPG, HbA1c, physical activity level and dietary habits were investigated. In 2011 participants and their family doctors were informed about their health conditions and indications concerning realistic changes for a healthier lifestyle were provided. Results: Complete information was obtained on 742 out of 1233 individuals. In 2011, the prevalence of PD was 30.7% of which 12.7% developed T2D and 43.9% reversed to normal glucose tolerance (NGT) at follow-up. In 2015, 106 previously NGT participants developed PD. The progression as to T2D as to PD were associated with age (P < 0.001) and sex (P < 0.001). Body weight, BMI, and waist circumference were higher in people with PD than in those without PD and even higher in PD that developed T2D (P < 0.001). A sedentary lifestyle was observed in the PD and NGT subgroups which developed T2D and PD, respectively. Daily energy intake decreased among people with PD who became NGT (P < 0.001) and increased in those who developed T2D (P < 0.05). The glycemic index of diet decreased in those PD people who became NGT and in those people who maintained NGT at follow-up. The MEDILITE score, that describes the Mediterranean pattern of diet, increased significantly in PD group that became NGT and in NGT group that maintained NGT at final observation. Conclusions: This study suggests that improving individual motivation may be an effective strategy to promote healthier lifestyles. A more physically active lifestyle and Mediterranean dietary habits are associated with a reduction of central obesity, and with a favorable evolution of glucose tolerance in PD people. Clinical trial registration: ISRCTN15840340