In univariable logistic regression analysis, the odds ratio (OR) of experiencing critical condition was significantly higher in patients with a higher CTSL level (OR, 1.53 per ng/ml; 95% CI, 1.19–1.96; P = 0.001) and older age (OR, 1.94 per 10 years; 95% CI, 1.31–2.88; P = 0.001), while CTSB, ACE2, Ang(1–7), sex, and coexistence of diabetes or hypertension did not significantly contribute to the odds of experiencing critical condition (Fig. 1g). Here, CTSL is linked to diabetes mellitus.