Fraction of exhaled nitric oxide in healthy elderly Tunisian subjects.

INTRODUCTION: Exhaled-fraction-of-nitric-oxide (FeNO) norms are absent in healthy elderly North-African subjects. OBJECTIVES: i) to identify FeNO influencing factors of elderly Tunisians older 50 years and more; ii) to assess the applicability of some published FeNO norms for elderly in local population; iii) to set-up FeNO norms and to prospectively evaluate their validity in two elderly validation-groups (healthy and asthmatic subjects). METHODS: A convenience sample of healthy and asthmatic elderly Tunisians was recruited. Subjects responded to a medical questionnaire and then FeNO levels were measured by an online method (Medisoft, Sorinnes (Dinant), Belgium). Clinical, anthropometric and spirometric data were collected. Three groups of subjects were identified: group I (healthy-elderly; n = 100, 57 females); group II (healthy-validation; n = 17, 4 females) and group III (asthmatic-validation; n = 10, 9 females). ANOVA was performed to compare the three groups' data. RESULTS: No significant factor, among those evaluated, influenced Tunisian elderly FeNO values. The available published FeNO norms did not reliably predict FeNO in Tunisian elderly population. The mean ± SD (minimum-maximum) of FeNO (ppb) for group I was 14 ± 6 (3-34). For Tunisian people, each elderly FeNO value higher than 34 ppb will be considered as abnormal. There was no statistical significant difference between FeNO (ppb) mean values of group I and groups II (15 ± 8) or III (18 ± 13). No subject of group II had a FeNO value higher than 34 ppb. Thirty percent of group III subjects had a FeNO value higher than 34 ppb. CONCLUSION: In practice, FeNO value of more than 34 ppb is considered abnormal in elderly Tunisian population.

Fraction of exhaled nitric oxide (FeNO ) norms in healthy Tunisian adults.

AIMS: To establish FeNO norms for healthy Tunisian adults aged 18-60 years and to prospectively assess their reliability. METHODS: This was a cross-sectional analytical study. A convenience sample of healthy Tunisian adults was recruited. Subjects responded to a medical questionnaire, and then FeNO levels were measured by an online method (Medisoft, Sorinnes (Dinant), Belgium). Clinical, anthropometric, and plethysmographic data were collected. All analyses were performed on natural logarithm values of FeNO. RESULTS: 257 adults (145 males) were retained. The proposed reference equation to predict FeNO value is lnFeNO (ppb) = 3.47-0.56× height (m). After the predicted FeNO value for a given adult was computed, the upper limit of normal could be obtained by adding 0.60 ppb. The mean ± SD (minimum-maximum) of FeNO (ppb) for the total sample was 13.54 ± 4.87 (5.00-26.00). For Tunisian and Arab adults of any age and height, any FeNO value greater than 26.00 ppb may be considered abnormal. Finally, in an additional group of adults prospectively assessed, we found no adult with a FeNO higher than 26.00 ppb. CONCLUSION: The present FeNO norms enrich the global repository of FeNO norms that the clinician can use to choose the most appropriate norms.

Oxidative stress and lung function profiles of male smokers free from COPD compared to those with COPD: a case-control study.

BACKGROUND: The mechanisms of smoking tobacco leading to chronic obstructive pulmonary disease (COPD) are beginning to be understood. However, conclusions about the role of blood or lung oxidative stress markers were disparate. AIMS: To investigate the oxidative stress in blood or lung associated with tobacco smoke and to evaluate its effect on pulmonary function data and its relation with physical activity. METHODS: It is a case-control study. Fifty-four male-smokers of more than five pack-years (PY) and aged 40-60 years were included (29 Non-COPD, 16 COPD). Physical activity score was determined. Blood sample levels of malondialdehyde (MDA), protein-cys-SH (PSH), and Glutathione (GSH) were measured. Fractional exhaled nitric oxide (FeNO) and plethysmographic measurements were performed. Correlation coefficients (r) evaluated the association between oxidative stress markers and independent variables (plethysmographic data and physical activity score). RESULTS: Non-COPD (48 ± 6 years) and COPD (49 ± 5 years) groups had similar tobacco consumption patterns, that is, 27 ± 14 PY versus 30 ± 19 PY, respectively. Compared to the Non-COPD group, the COPD group had significantly lower levels of GSH and PSH, that is, mean ± SE were 40 ± 6 versus 25 ± 5 µg/mL and 54 ± 10 versus 26 ± 5 µg/g of hemoglobin, respectively. However, MDA level and FeNO values were similar. In the COPD group, none of the oxidative stress markers was significantly correlated with plethysmographic data or physical activity score. In the Non-COPD group, GSH was significantly correlated with physical activity score (r = 0.47) and PSH was significantly correlated with total lung capacity (TLC) (r = -0.50), residual volume (r = 0.41), and physical activity score (r = 0.62). FeNO was significantly correlated with TLC of the COPD group (r = -0.48). CONCLUSION: Compared to the Non-COPD group, the COPD group had a marked decrease in blood antioxidant markers (GSH and PSH) but similar blood oxidant (MDA) or lung (FeNO) burden.