Table 6.

Effect of anti-diabetic medications on endothelial progenitor cells

Ref.	Subjects	Drugs	Duration	EPCs (number/function)	Findings
Thiazolidinedione/metformin
Wang et al[54]	36 type 2 diabetes	Metformin + Pioglitazone (30 mg/d) (n = 24) vs Metformin (n = 12)	8 wk	CD34+/KDR+ (flow cytometry) Migratory activity	Both EPC number and migration activity improved with combination of metformin and pioglitazone
Werner et al[55]	54 CAD	Pioglitazone (45 mg/d) vs Placebo	4 wk	CFU CD34+ (flow cytometry)	Improved EPC number and CFU count with pioglitazone treatment
Makino et al[56]	34 type 2 diabetes	Pioglitazone (15-30 mg/d)	24 wk	CD34+ (flow cytometry)	Number of CD34+ increased steadily at 12 wk and continued to increase after 24 wk of pioglitazone
Esposito et al[57]	110 type 2 diabetes	Pioglitazone (15-45 mg/d) (n = 55) vs Metformin (1000-2000 mg/d) (n = 55)	24 wk	CD34+/KDR+ (flow cytometry)	Significant improvement in CD34+/KDR+ in patients who took pioglitazone compared to metformin
Liao et al[58]	51 healthy controls 46 type 2 diabetes	Metformin (1700-2550 mg/d)	16 wk	CD45-/CD34+/KDR+ (flow cytometry)	EPC number is significantly lower in type 2 diabetic patients and significantly improved after metformin
Dipeptidyl peptidase 4 inhibitors
Fadini et al[59]	32 type 2 diabetes	Sitagliptin (100 mg/d) (n = 16) vs Metformin (n = 16)	4 wk	CD34+/KDR+ (flow cytometry)	EPC number in sitagliptin group significantly improved compared to metformin group by 2 fold

CAD: Coronary artery disease; CFU: Colony forming unit; EPC: Endothelial progenitor cells.