Post-prandial glucose and diabetic complications: systematic review of observational studies

Post-prandial hyperglycemia is considered a relevant therapeutic target in type 2 diabetic patients, and it could represent per se an independent risk factor for diabetic complications. Aim of the present systematic review is to collect and summarize evidence from observational studies on the relationship between post-prandial glucose (PPG) and cardiovascular or microvascular disease in patients with diabetes. An extensive search of Medline (any date up to December 31, 2010) was performed for all longitudinal epidemiological studies with a cohort design. The following endpoints were taken into consideration: death from any cause; cardiovascular death and micro- and macrovascular complications. The number of epidemiological studies assessing the relationship between PPG and microvascular or cardiovascular disease in subjects with diabetes is surprisingly scarce. In fact, of the 391 retrieved studies, only 8 fulfilled the inclusion criteria. Most of those investigations enrolled small samples, which in many instances were not representative of the general population. Furthermore, the assessment of PPG varied widely across studies. These considerations prevent any formal meta-analysis. Despite this, the few available studies show that higher PPG is associated with increased all-cause and cardiovascular death, incidence of major cardiovascular events (including myocardial infarction and stroke), and progression of diabetic retinopathy.