Table 1.

Inclusion and exclusion criteria

Inclusion criteria	Exclusion criteria
Published between 2007 and 2019	Published before 2007
English language	Languages other than English
Systematic reviews (SRs) with or without meta-analyses (MAs) of RCTs, umbrella reviews of SRs/MAs of RCTs	Abstracts, posters, conference proceedings, editorials or commentaries, duplicate studies, narrative reviews, RCTs, observational studies/both cohort and case–control and systematic reviews of observational studies and/or case-control studies
Baseline and outcome measurement of HbA1c
Studies involving humans	Animal studies (in vivo, ex vivo) and in vitro studies