Fig. 4
Meta-regression analysis for factors associated with placebo response in diabetes mellitus. a Association between age and placebo response on HbA1c change in type 1 diabetes (β = − 0.01, 95% CI, − 0.02 to − 0.01, P < 0.01). b Association between age and placebo response on HbA1c change in type 2 diabetes (β = 0.02, 95% CI, 0.01 to 0.03, P < 0.01). c Association between male percentage and placebo response on HbA1c change in type 2 diabetes (β = 0.01, 95% CI, 0.22 × 10−2 to 0.01, P < 0.01). d Association between baseline BMI and placebo response on HbA1c change in type 2 diabetes (β = − 0.02, 95% CI, − 0.04 to − 0.26 × 10−2, P = 0.02). e Association between baseline HbA1c and placebo response on HbA1c change in type 2 diabetes (β = − 0.09, 95% CI, − 0.16 to − 0.01, P = 0.02). f Association between diabetes duration and placebo response on HbA1c change in type 1 diabetes (β = − 0.02, 95% CI, − 0.03 to − 0.21 × 10−2, P = 0.03). g Association between diabetes duration and placebo response on weight change in type 2 diabetes (β = 0.06, 95% CI, 0.02 to 0.10, P < 0.01)