Metabolic control in type 2 diabetes mellitus - Everything under or out of control?

Systematic reviews and meta-analyses may particularly, if implemented adequately, overcome the limitations of studies with low numbers of cases and event rates and result in more precise effect estimates of endpoints which are relevant for patients. Guidance on the establishment and reporting of high-quality systematic reviews do exist and emphasize, among other things, the importance of an investigation of the risk of bias in the included single studies as well as a thorough analysis of endpoint ascertainment and adequate statistical analysis. The role of clinical heterogeneity, that is mainly the variability in the included patient populations with their associated charateristics like co-morbidities and co-medications, should in future receive more attention in meta-analyses. The existing eight systematic reviews and meta-analyses comparing intensive versus less intensive blood sugar control in type 2 diabetes show different grades of deficiencies; the analyses share the result that intensive metabolic control in type 2 diabetes leads to a reduction in cardiovascular events especially in myocardial infarction rates with a concomitant increase in serious hypoglycaemic episodes. Present data do not indicate a definite HbA1c threshold for the care of all type 2 diabetes patients. Therefore, individualised therapy appears inevitable, particularly in elderly and more diseased type 2 diabetes patients. Furthermore, complex risk constellations in type 2 diabetes have to be taken into account; antidiabetic medications used have to be individually adapted according to their potential for harm, and therapy should not focus on lowering of blood glucose only but also, for example, on effective treatment of hypertension. © Deutscher Ärzte-Verlag.