Variability of salivary markers of oxidative stress and antioxidant status in young healthy individuals

Figures & data

Table 1 Descriptive statistics of all measured parameters

	Mean and SD		CV (inter-individual) (%)		CV (intra-individual) – Range (%)
Parameter	Females	Males	Females	Males	Females	Males
AGEs (g/l)	0.23 ± 0.13	0.27 ± 0.19*	56.08	69.15	17.45–69.22	21.21–62.53
AOPP (μmol/l)	29.27 ± 17.77	37.68 ± 23.33**	60.72	61.92	32.56–61.02	29.61–122.75
TAC (μmol trolox eq./l)	531.3 ± 149.9	582.2 ± 173.7**	28.21	29.83	8.00–38.11	3.08–57.28
FRAS (μmol/l)	321.3 ± 138.1	459.7 ± 221.4**	42.96	48.15	16.24–84.78	13.06–113.59

Mean and standard deviation, inter-individual and intra-individual variability. AGEs – advanced glycation end-products, AOPP – advanced oxidation protein products, TAC – total antioxidant capacity, FRAS – ferric reducing ability of saliva, SD – standard deviation, and CV – coefficient of variation.

*P < 0.05.

**P < 0.001 when compared to females.

Figure 1 Salivary AGEs (A), AOPP (B), TAC (C), and FRAS (D) levels in females and males. All analyzed samples are plotted. AGEs – advanced glycation end-products, AOPP – advanced oxidation protein products, TAC – total antioxidant capacity, and FRAS – ferric reducing ability of saliva. * denotes P < 0.05, *** denotes P < 0.001 when compared to females.

Table 2 Repeated measures two-way ANOVA – selected components of variability

	Gender	Day of sampling
AGEs	F = 0.1495	F = 0.9061
	P = 0.7019	P = 0.6101
	ns	ns
AOPP	F = 2.415	F = 1.764
	P = 0.1310	P = 0.0081
	ns	**
TAC	F = 1.031	F = 1.187
	P = 0.3182	P = 0.2291
	ns	ns
FRAS	F = 6.743	F = 0.8548
	P = 0.0146	P = 0.6876
	*	ns

AGEs – advanced glycation end-products, AOPP – advanced oxidation protein products, TAC – total antioxidant capacity, FRAS – ferric reducing ability of saliva, F – F-ratio, P – P value, and ns – not significant.

*P < 0.05.

**P < 0.01.

Figure 2 Intra-individual variability of AGEs (A), AOPP (B), TAC (C), and FRAS (D). AGEs – advanced glycation end-products, AOPP – advanced oxidation protein products, TAC – total antioxidant capacity, and FRAS – ferric reducing ability of saliva.