Effects of age, gender, and environmental exposures on exhaled nitric oxide level in healthy 12 to 18 years Qatari children

Relationship between total serum immunoglobulin E levels, fractional exhaled breath nitric oxide levels and absolute blood eosinophil counts in atopic and non-atopic asthma: a controlled comparative study

OBJECTIVE

Asthma is a prevalent non-communicable disease both in low- and high-income countries, including Nepal. Total serum immunoglobulin E levels and peripheral blood absolute eosinophil counts are known inflammatory markers of asthma. Fractional exhaled nitric oxide measurement in breath has also been proposed as a non-invasive biomarker to assess eosinophilic airway inflammation. This study explores the correlation between these three variables with the intent that one may replace the other in resource-limited setups.

APPROACH

This prospective controlled trial evaluated 314 subjects with and without asthma, with the asthma group sub-divided into atopic and non-atopic categories. Total serum immunoglobulin E level, absolute eosinophil count in peripheral blood and fractional exhaled nitric oxide level were measured in all categories.

RESULTS

The geometric mean of immunoglobulin E levels, absolute eosinophil count and fractional exhaled nitric oxide were 221.07 ± 774.55 IU/mL, 214 ± 360/uL and 37 ± 49 ppb in the asthma group and 59.13 ± 174.32 IU/mL, 164 ± 137/uL and 12 ± 21 ppb in the control group, respectively. Significantly higher levels were seen in the asthma group for total serum immunoglobulin E (p < 0.001), AEC (p = 0.002) and F_ENO (p < 0.001) levels. Total serum immunoglobulin E levels, absolute eosinophil count and fractional exhaled nitric oxide were 436.79 ± 822.40 IU/mL, 269 ± 395/uL and 76 ± 52 ppb in atopic asthma group. Similarly, total serum immunoglobulin E levels, absolute eosinophil count and fractional exhaled nitric oxide were 131.17 ± 692.96 IU/mL, 182 ± 328/uL and 23 ± 22.5 ppb in non-atopic asthma group. Significantly higher levels were seen in all three variables: tIgE (p < 0.001), AEC (p =  0.008) and F_ENO (p < 0.001). A moderate degree of positive correlation was identified between tIgE and F_ENO₅₀ (Spearman's rho = 0.461) and tIgE and AEC (Spearman's rho = 0.315) with only small correlation between F_ENO₅₀ and AEC (Spearman's rho = 0.299).

SIGNIFICANCE

tIgE levels, F_ENO₅₀ and AEC levels are higher in asthma, specifically in the atopic phenotype, as compared to normal. Total serum IgE levels have moderate correlation with F_ENO₅₀ and AEC but F_ENO₅₀ and AEC are weakly correlated.

Normal values of nasal NO and exhaled NO in young Chinese people aged 9 - 22 years

Objective

To assess the normal levels of nasal nitric oxide (NNO) and fractional exhaled nitric oxide (FENO) in healthy Chinese young people, and to determine whether the obtained values were associated with age, sex, height, weight, BMI (body mass index) or BSA (body surface area).

Methods

One hundred and twenty healthy people were selected from a total of 436 Chinese young people based on their answers to a questionnaire. An electrochemical analyzer (NIOX MINO system) was used to measure NNO and FENO. The relationship between NNO, FENO and age, sex, height, weight, BMI, BSA was analyzed using SPSS software.

Results

The values of NNO were normal distributed (mean 273.5 ppb; SD 112.3). The values of FENO were non-normally (Skewed) distributed (median: 14.00 ppb; interquartile range: 7.00 ppb). The obtained NNO values were independent of age, sex, height, weight, BMI and BSA, but were positively correlated to lnFENO (FENO log base e); lnFENO values were also independent of age, height, weight, BMI and BSA, but correlated with NNO and sex.

Conclusions

NNO values positively correlate with lnFENO in healthy people and the levels of each may be predicted by the other. The results of this study are expected to serve as a reference for future studies in China.

Fraction of exhaled nitric oxide in healthy Chilean schoolchildren aged 8-15 years

BACKGROUND

The fraction of exhaled nitric oxide (FENO) measured using portable devices is increasingly used in the clinical setting to assess asthmatic children. However, there is little and variable information on the reference values obtained using these devices in healthy children from different populations.

METHODS

190 healthy non-smoker children (8-15 years old) were randomly selected from public schools participating in this study. The objective was to determine FENO reference values for healthy Chilean schoolchildren. Healthy individuals were identified by medical interview and parent questionnaire on the use of asthma medications, and current and past symptoms of asthma, rhinoconjunctivitis and eczema. FENO was measured at schools using a portable device with electrochemical sensor (NIO MINOX). Reference values of FENO were expressed as geometric mean and upper limit of the 95% reference interval (right-sided). The relationship of FENO with gender, age, height, body mass, and other factors was assessed by multiple regression, and the difference between groups was contrasted by ANOVA.

RESULTS

The FENO geometric mean was 15.4ppb with a 95% reference interval upper limit (right-sided), of 27.4ppb (90%CI 25.6-29.2). The 5th and 95th percentiles were 9.0ppb and 28.0ppb, respectively. Height was the only factor significantly associated to FENO (p=0.022). There was no significant difference in mean FENO regarding age, gender, weight, parent reported rhinoconjunctivitis and eczema.

CONCLUSION

This study suggests that FENO values higher than 27ppb are likely to be abnormal and would reflect airway inflammation in children as those in the present study.

Trace elements concentration in nails and association with airway inflammation in adolescents

Asthma is a multifactorial disease and its severity varies with the inflammatory status of the patient. It has been hypothesized that deficiency of trace elements has an important role in the etiology of asthma. The aim of the study was to evaluate the concentration of trace elements in nails of adolescents with different degrees of airway inflammation. We assessed the prevalence of active and severe asthma in adolescents (n = 106) through the ISAAC questionnaire. Subjects were allocated into two different groups according to the value of fraction exhaled nitric oxide (FeNO) measured. Also, nail specimens were collected in order to determine the concentration of accumulated trace elements (Cu, Zn, Mn, Se) by ICP-MS. It was performed Student's t test to evaluate statistical differences between inflammatory groups considering normally distributed data. On the other hand, when data presented non-normal distribution, Mann-Whitney U test was utilized. Spearman coefficients were calculated to investigate correlations between FeNO and mineral concentrations. Exhaled NO was increased in male subjects. We found association between active asthma and elevated exhaled NO. There was no significant difference in Cu (4.40 vs. 4.52), Zn (84.66 vs. 79.48), Mn (0.59 vs. 0.76), and Se (0.18 vs. 0.19) concentrations (μg/g) among distinct FeNO groups as well as was not observed correlation between exhaled NO levels and any element. Deficiency of trace elements in nails were not associated with increased FeNO.