marginally significantP <0.00001
Using fixed-effects model, the results showed that the patients with hypothyroidism had a marginally significant reduction in CI compared with healthy controls (WMD=-0.53, 95%CI[-0.65, -0.41], P <0.00001), and heterogeneity analysis showed large heterogeneity (Tau2=0.21, Chi2=44.02, P < 0.00001, I 2 = 93%).