RESUMEN
BACKGROUND: The reduction of hemoglobin A1c (HbA1c) levels is recognized as a useful means of preventing diabetic complications. HbA1c results from both fasting and post-prandial glycemia, and therefore FPG and PPG could provide different, and independent, contributions to long-term outcomes. Aim of the present meta-analysis is the assessment of the effects of reduction of FPG and PPG on cardiovascular outcomes in randomized controlled trials. METHODS: An extensive search of Medline was performed for all randomized trials with a duration of at least 52 weeks and performed on glucose-lowering agents. Differences in the incidence of cardiovascular events, and all-cause and cardiovascular mortality were assessed in trials comparing different treatments with a between-group difference in FPG or PPG at endpoint greater than 1 mmol/l. RESULTS: The Mantel-Haenszel Odds Ratio (MH-OR) for cardiovascular events and all-cause and cardiovascular mortality in patients on more intensive treatments, in trials with a between-group difference of PPG greater than 1 mmol/l, was not significantly different from controls (MH-OR [95%CI] 0.90 [0.51-1.58] for MACE); on the contrary, more intensive treatment of FPG produced a significantly lower all-cause (MH-OR 0.90 [0.81-0.99], p = 0.03) and cardiovascular (MH-OR 0.86 [0.76-0.97], p = 0.012) mortality, with no significant effect on the incidence of major cardiovascular events. CONCLUSIONS: In conclusion, reduction of FPG is associated with reduced cardiovascular mortality. Data on PPG are still scarce, but they point in the same direction.