Excluded studies
Three studies had to be excluded after careful evaluation of
the full publication (Graham 2005; Wainstein 2011; Ziegenfuss
2006). Main reasons for exclusion were, failure to meet the criteria
for diagnosis of type 1 or type 2 diabetes mellitus (Graham
2005; Ziegenfuss 2006), and use of a combination preparation
(Wainstein 2011). For further details, see Characteristics of
excluded studies.