Fig. 4

Forest plot of hazard ratios for various patient characteristics with or without DPP-4 inhibitor (DPP-4i). DPP-4 inhibitors therapy is beneficial in both male and female patients. DPP-4i therapy is beneficial in patients who are 65 ≤ age < 75 (HR = 0.83; 95% CI 0.69–0.99; P = 0.0414). In addition, a positive effect of DPP-4i can be seen in patients without dyslipidemia (HR = 0.78; 95% CI 0.67–0.92; P = 0.0029), without peripheral vascular disease (PVD) (HR = 0.86; 95% CI 0.78–0.96; P = 0.0047), without heart failure (HF) (HR = 0.84; 95% CI 0.73–0.96; P = 0.0106), without end stage renal disease (ESRD) (HR = 0.86; 95% CI 0.77–0.95; P = 0.0035), and those without chronic obstructive pulmonary disease (COPD) (HR = 0.87; 95% CI 0.78–0.97; P = 0.0096). DPP-4i are also beneficial in patients with hypertension (HR = 0.87; 95% CI 0.78–0.97; P = 0.0103) and cerebrovascular disease (HR = 0.83; 95% CI 0.72–0.97; P = 0.018)