Table 4. Safety profile of patients with NPDR.

	Placebo (n = 20)			Coenzyme Q10 (n = 20)			Combined antioxidant therapy (n = 20)
	Baseline	Final	P	Baseline	Final	P	Baseline	Final	P	P
			WCX			WCX			WCX	K–W
Uric acid (mg/dl)	5.6 ± 0.3	4.9 ± 0.3	NS	5.1 ± 0.2	4.9 ± 0.2	NS	5.7 ± 0.2	5.6 ± 0.3	NS	NS
TB (mg/dl)	0.6 ± 0.1	0.6 ± 0.2	NS	0.5 ± 0.0	0.6 ± 0.1	NS	0.5 ± 0.0	0.5 ± 0.0	NS	NS
DB (mg/dl)	0.2 ± 0.0	0.3 ± 0.0	NS	0.3 ± 0.0	0.2 ± 0.0	NS	0.2 ± 0.0	0.2 ± 0.0	NS	NS
IB (mg/dl)	0.4 ± 0.0	0.3 ± 0.0	NS	0.3 ± 0.0	0.4 ± 0.1	NS	0.3 ± 0.0	0.4 ± 0.0	NS	NS
Urea (mg/dl)	36.1 ± 3.5	35.9 ± 4.1	NS	32.6 ± 2.6	32.5 ± 1.6	NS	37.2 ± 2.8	41.9 ± 4.2	NS	NS
Cr (mg/dl)	0.9 ± 0.1	0.9 ± 0.1	NS	0.8 ± 0.1	0.8 ± 0.0	NS	0.9 ± 0.1	1.0 ± 0.1	NS	NS
AST (IU/l)	28.0 ± 2.3	24.0 ± 1.5	NS	29.8 ± 2.5	29.4 ± 2.9	NS	28.9 ± 1.5	24.6 ± 1.4	NS	NS
ALT (IU/l)	31.2 ± 1.9	30.2 ± 1.9	NS	34.6 ± 3.1	36.7 ± 3.7	NS	30.3 ± 1.9	30.1 ± 1.6	NS	NS

The table illustrates the metabolic profile per study group, where values are expressed as mean ± standard error. Significant differences were not observed between study groups, which suggests that the medications evaluated were safe (Wilcoxon and Kruskal–Wallis tests).

NPDR, non-proliferative diabetic retinopathy; mg/dl, milligram/decilitre; UI/l, international units per liter; WCX, Wilcoxon test; K–W, Kruskal–Wallis test; NS, not significant.