Effect of individual risk factors and medications on NO production from EPCs. (a) Effect of individual risk factors on NO production by EPCs of all diabetic patients. (b) Association between the individual medications that was taken by the type 2 diabetic patients and NO production by their EPCs. Increased NO production by EPCs was associated with the use of statins only. Data are expressed as mean percentage ± SEM. *P < 0.05, **P < 0.01.