*3.3. Increased Systemic Generation of Protein Hydroperoxides in Asthma*

The fluorescent intensity of the CBA-assay product, reflecting HP generation, increased quickly both in the asthmatics and controls (Figure 2a). However, the velocity of fluorescence growth, reflected by the factor R, was 35% higher, and the saturating concentration (K) increased by 23% more in asthmatics than in controls (*p* < 0.001, using the Mann–Whitney U test; *p* = 0.01 and *p* = 0.009, respectively, using ANCOVA after adjustment for age, sex, and BMI) (Figure 2b).

Compared to the control subjects, asthma patients showed an odds ratio (OR) of 3.14 (95%CI: 1.98–4.97; *p* < 0.001) for having a higher R factor, defined as values above the cut-off point of 42.4 fluorescence (FL) unit (U)/mL/min. Similarly, asthma patients had an OR of 2.57 (95%CI: 1.7–3.88; *p* < 0.001) for having increased K concentration, using a cutoff point of 322 FLU/mL.

Furthermore, we demonstrated a 58% higher cumulative in time HP generation (area under the curve) (Figure 2b, *p* < 0.001, using Mann–Whitney U test; *p* = 0.01, using ANCOVA after adjustment for age, sex, and BMI).

In the asthma group, the dynamics of HP generation were ~20% higher, and K concentration was increased by ~15% in females (Figure 3).

**Figure 2.** (**a**) Representative curve of fluorescent product generation in the real-time coumarin boronic acid (CBA) assay of asthma patient and control individual (K—saturating concentration). (**b**) Saturating concentration (K), growth velocity (R factor), and cumulative fluorescent (FL) product generation in the real-time coumarin boronic acid (CBA) assay in asthma and control subjects. Abbreviations: FL—fluorescent, FLU—fluorescent unit, K—saturating concentration, R—velocity of fluorescent product growth, \*\* *p* < 0.001.

**Figure 3.** Hydroperoxides' generation in the coumarin boronic acid (CBA) assay was higher in females than males in the asthma group; \* *p* < 0.05; for other abbreviations, see legend in Figure 1.

Other demographic variables and comorbidities had no impact on the CBA assay results.
