Where mean (SD) age of study participants was available, this ranged from 48.8 (9.8) to 58.8 years (7.7).21,23 Where median (IQR) age was available, this ranged from 53 (41–58) to 60 years (54–69) in the intervention groups and 50 (39–62) to 62 years (56–69) in the control groups.29,52 Participants in the included studies had pre-existing T2DM and were on a range of treatments, including diet control only, oral antidiabetic drugs, and insulin. Here, INS is linked to type 2 diabetes mellitus.