For each of the polymorphisms where we identified moderate or larger estimates of between-study heterogeneity (I2≥25%), we discuss the potential insight that may be offered by this heterogeneity and how it may affect or not the interpretation of the results. We also retrieved additional studies that have been published on the same or linked polymorphisms as of May 12, 2007 on type 2 diabetes or related phenotypes so as to consider potentially additional evidence from other relevant studies in the interpretation of the results. Additional studies were identified by PubMed searches using “diabetes” and “association” limited to the year 2007. Relevant additional data that were available were also incorporated into updated random effects meta-analyses.
