Fraction of exhaled nitric oxide in healthy elderly Tunisian subjects.
BACKGROUND
Exhaled-fraction-of-nitric-oxide (FeNO) norms are absent in healthy elderly North-African subjects.


OBJECTIVE
i) to identify FeNOinfluencing factors of elderly Tunisians older 50 years and more; ii) to assess the applicability of some published FeNOnorms for elderly in local population; iii) to set-up FeNOnorms 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 FeNOlevels 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 FeNOvalues. The available published FeNOnorms did not reliably predict FeNOin Tunisian elderly population. The mean ± SD (minimum-maximum) of FeNO(ppb) for group I was 14 ± 6 (3-34). For Tunisian people, each elderly FeNOvalue 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 FeNOvalue higher than 34 ppb. Thirty percent of group III subjects had a FeNOvalue higher than 34 ppb.


CONCLUSIONS
In practice, FeNOvalue of more than 34 ppb is considered abnormal in elderly Tunisian population.
Laboratory of Physiology, Faculty of Medicine of Sousse, University of Sousse, 4000 Sousse, Tunisia; Department of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia. Electronic address: sfx.ines@gmail.com.
Ines
I
Sfaxi
Laboratory of Physiology, Faculty of Medicine of Sousse, University of Sousse, 4000 Sousse, Tunisia; Department of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia; Research Laboratory N° LR14ES05: Interactions of the Cardiopulmonary System, Faculty of Medicine of Sousse, University of Sousse, Tunisia.
Helmi
H
Ben Saad
Laboratory of Physiology, Faculty of Medicine of Sousse, University of Sousse, 4000 Sousse, Tunisia; Department of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia.
Sonia
S
Rouatbi
Elderly; Eosinophilic inflammation; Fe(NO); Norms; North Africa