Table 4.

Comparison of medians between the groups using the Mann–Whitney U test

	Poorly controlled asthma (n = 20)	Well controlled asthma (n = 24)	Healthy controls (n = 27)	p-value
Serum nitrate concentration/μM	4.79 ± 2.15	3.93 ± 3.28		0.311
Serum NOx concentration/μMa	5.06 ± 2.31	4.05 ± 3.32		0.203
Serum nitrate concentration/μM		3.93 ± 3.28	3.34 ± 2.15	0.036*
Serum NOx concentration/μMa		4.05 ± 3.32	3.53 ± 2.35	0.049*
Serum nitrate concentration/μM	4.79 ± 2.15		3.34 ± 2.15	0.001*
Serum NOx concentration/μMa	5.06 ± 2.31		3.53 ± 2.35	< 0.001*
Serum TAOC/μM	333.20 ± 36.39	360.02 ± 34.10		0.003*
Serum TAOC/μM		360.02 ± 34.10	362.45 ± 12.45	0.496
Serum TAOC/μM	333.20 ± 36.39		362.45 ± 12.45	< 0.001*

^aNO_x denotes NO₂⁻ and NO₃⁻ collectively

*p < 0.05 comparison between the three study groups (Mann–Whitney U test)