Characteristics of subjects with type 2 diabetes enrolled in randomized controlled trials and non-randomized controlled trials in Japan: A systematic review

Abstract

Aims/Introduction: This study aimed to understand the characteristics of type 2 diabetes subjects enrolled in randomized controlled trials (RCTs) and non-RCTs according to therapeutic regimens through systematic literature review. Materials and Methods: PubMed and the database of the Japanese Medical Abstract Society (ICHUSHI) were searched for studies published from 2010 to 2019 reporting the efficacy and safety of glucose-lowering drugs in Japanese individuals with suboptimally controlled type 2 diabetes, and therapeutic regimens, demographics and clinical characteristics at the baseline were extracted. We evaluated the treatment arms, not the placebo arms. Results: The literature searches identified 2,656 publications, 145 of which met all eligibility criteria and included 282 eligible arms. In the past 10 years, dipeptidyl peptidase-4 inhibitor was the most frequently studied in both RCTs and non-RCTs. Regarding the characteristics of enrolled subjects, sodium–glucose cotransporter 2 inhibitor and glucagon-like peptide-1 receptor agonist have been studied more in relatively obese subjects, and insulin has been studied in higher proportion of subjects with disease duration ≥10 years. Most of the RCTs included subjects aged 55–64 years, whereas a higher proportion of dipeptidyl peptidase-4 inhibitor and insulin arms in the non-RCTs included those aged ≥65 years. Dipeptidyl peptidase-4 inhibitor and sodium–glucose cotransporter 2 inhibitor were evaluated in subjects with no abnormalities in blood pressure or lipid parameters; however, only a few reports of those parameters have been assessed with glucagon-like peptide-1 receptor agonist and insulin. Conclusions: As RCTs and non-RCTs differ in the baseline characteristics of type 2 diabetes subjects, it is necessary to integrate and evaluate both to understand the actual treatment status of type 2 diabetes.