[Factors influencing pulmonary function in Tunisian women aged 45 years and more]

Why a large percentage of Tunisian women aged 40 years and more has a reduced forced vital capacity? The implication of parity

The investigation of the link between reduced forced vital capacity (FVC) and risk factors and health variables in women aged ≥ 40 years is encouraged since a reduced FVC was related to all-cause mortality. The high frequency of women with a reduced FVC, observed in some studies, could be related to the impacts of parity on lung. In the literature, the association between parity and health consequences is discussed in terms of “selection pressure”, and the trade-off between longevity and fertility described by scientists is termed the “longevity determination” or “biological warranty period”. The respiratory system could be influenced by parity. Above all, it is the respiratory system, who endures the repercussions of the numerous physio-pathological experiences of the woman life. The probable effects of parity on lung function data, including FVC, make parity a key predictor to be stressed and evaluated. Parity is a promising original direction for physiological and pathophysiological research, particularly for low- and lower-middle- income countries. Thus, upcoming epidemiological and clinical studies of lung function data in women would need to include information about their parity status.

Evaluation of the Global Lung Function Initiative 2012 reference values for spirometry in an Iranian population

Spirometry is an important measurement in detecting and monitoring of chronic obstructive pulmonary disease. The validity of the multi-ethnic Global Lung Function Initiative 2012 (GLI-2012) spirometric norms have been debated in some countries. The aim of the present study was to evaluate the applicability of the GLI reference norms in the Iranian population. A cross-sectional study was performed on 622 healthy non-smoker population (204 males and 418 females, age range: 4 ± 82 years) between July 16 and August 27, 2019 in Iran. Z-scores for spirometric data [FEV₁ (forced expiratory volume in 1 s), FVC (forced vital capacity) FEV₁/FVC, and FEF_25-75% (forced expiratory flow averaged over the middle portion of FVC)] were calculated. According to the agreement approved, a mean Z-score outside the range of ± 0.5 was considered clinically significant. The mean (SD) Z-score values of FEV₁, FVC, FEV₁/FVC and FEF_25-75% were 0.44 (1.21), 0.49 (1.14), 0.11 (1.03), and - 1.13 (0.99) in males and 0.61 (1.14), 0.89 (1.26), 0.17 (0.88) and - 0.49 (0.96) in females, respectively. The Z-score of FEV₁/FVC was below the lower limit of normal (LLN) in 3.43% of men and 2.01% of women (in ≥ 21 years), while these values were significantly higher in people under 21 years old (46.2% in boys and 40.0% in girls). The GLI reference values are not perfect for the Iranian population, especially in children below 10 years old. The use of the GLI reference values was appropriate in population above 21 years; however, they would overestimate the prevalence of airway obstruction in individuals below 21 years.

The global lung function initiative 2021 (GLI-2021) norms provide mixed results for static lung volumes (SLVs) in Algerian adults

The validity of the GLI-2021 norms for SLVs in healthy Algerian adults has not been assessed. To ascertain how well do the GLI-2021 norms fit to contemporary SLVs data in Algerian adults. This was a cross-sectional study involving 481 (n = 242 females) healthy non-smoking adults recruited from the Algiers general population. All participants underwent a clinical examination and a plethysmography. Z-scores for slow vital capacity (SVC), functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), expiratory reserve volume (ERV), inspiratory capacity (IC), and RV/TLC were calculated. The mean difference between the determined and the predicted values (∆value) of SLVs were calculated. The GLI-2021 norms would be considered as reflective of contemporary Algerian SLVs if the total sample mean z-scores were in the normal range (ie; −0.5 to +0.5). The participants’ means ± SDs of age and height were 46.4 ± 16.4 years and 166 ± 10 cm, respectively. The determined SLVs were significantly different from those predicted (∆values means ± SDs were −170 ± 470 ml for IC, −100 ± 490 ml for SVC, 170 ± 400 ml for ERV, 240 ± 620 ml for TLC, 370 ± 340 ml for RV, 480 ± 480 ml for FRC, and 5.28 ± 4.38% for RV/TLC). The means ± SDs z-scores for IC, SVC, ERV, and TLC were in the normal range (−0.29 ± 0.88, −0.17 ± 0.94, 0.29 ± 0.77, and 0.35 ± 0.86, respectively), but those of RV, FRC, and RV/TLC were out of the normal range (0.74 ± 0.66, 0.75 ± 0.72, and 0.83 ± 0.75, respectively). In healthy Algerian adults, the GLI-2021 norms fit well to SVC, TLC, ERV, and IC, but they do not fit to FRC, RV, and RV/TLC.

Sex differences in pulmonary function parameters among Indigenous Australians with and without chronic airway disease

BACKGROUND

Studies assessing normative values and sex differences in pulmonary function test parameters (PFTPs) among Indigenous populations are sparse.

METHODS

PFTPs were compared between male and female Indigenous Australian adults with and without chest radiologically proven chronic airway diseases (CADs).

RESULTS

485 adults (56% were female) with no significant difference in age, body mass index or smoking status between sexes were included. Females displayed a higher prevalence of radiology without CADs compared to males (66 vs. 52%, respectively). Among patients without CADs, after adjustment for age, stature and smoking, males displayed significantly higher absolute values of Forced Vital Capacity (FVC) (mean difference, 0.41L (0.21,0.62), p<0.001) and Forced Expiratory Volume in one second (FEV1) (mean difference 0.27L (0.07,0.47), p<0.001), with no significant difference in FEV1/FVC ratio (mean difference -0.02 (-0.06, 0.02), p = 0.174). Male and female patients with radiologically proven CADs demonstrated lower FEV1/FVC values. However, compared to females, males showed significantly greater reductions in pre- [-0.53 (-0.74, -0.32) vs. -0.29 (-0.42, -0.16), p = 0.045] and post- [-0.51 (-0.72, -0.3) vs. -0.27 (-0.39, -0.14), p = 0.049] bronchodilator FEV1.

CONCLUSIONS

There are significant sex differences in the PFTPs among Indigenous Australians. Recognising these differences may be of value in the accurate diagnosis, management, monitoring and prognostication of CADs in this population.

Critical analysis of spirometric patterns in correlation to chest computed tomography among adult Indigenous Australians with chronic airway diseases

Background: There is sparse literature evidence in the spirometric patterns of adult Indigenous Australians with and without chest computed tomography (CT)-proven chronic airway diseases (CADs).Methods: Participants spirometry testing graded as acceptable for quality and had a chest CT scan showing radiographic evidence of CADs were included for analysis.Results: Of the 1350 spirometric tests performed between 2012 and 2020, a total of 212 patients with a mean age of 53 years and 54% females were eligible to be included. One-third (30%) had normal chest CT (without CADs), 35% had predominant COPD, 19% bronchiectasis and 16% combined COPD and bronchiectasis. Percentage predicted values for forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) both pre- and post- bronchodilator were significantly reduced for all participants - FVC: CT-normal 64%, 65%; COPD 58%, 62%; bronchiectasis 54%, 54%; combined COPD and bronchiectasis 50%, 53%. FEV₁: CT-normal 62%, 65%; COPD 46%, 49%; bronchiectasis 48%,51%; combined COPD and bronchiectasis 36%,40%. FEV₁/FVC was only reduced for CT abnormality patients - CT-normal 96%,98%; COPD 77%,77%; bronchiectasis 87%,89%; combined COPD and bronchiectasis 71%,72%.Conclusions: Restrictive spirometric pattern is common and an obstructive pattern with COPD, in isolation or when COPD coexists with bronchiectasis.

The impacts of parity on spirometric parameters: a systematic review

Introduction: The relationship between parity and health outcomes has been debated in the scientific literature in terms of 'selection-pressure'. However, no previous review has raised the impacts of parity on spirometric parameters. This Systematic Review aimed to review the impacts of parity on spirometric parameters.Areas covered: PubMed and Scopus were searched on October 1^st, 2020, using the combination of the following two medical subject headings: 'Parity' and 'Respiratory Function Tests'. Only original articles published in English/French were retained. Ten studies investigated the impacts of parity on spirometric parameters: six included healthy females, three involved unhealthy females [chronic obstructive pulmonary disease, defect in protease inhibitor, and some other conditions] and one included a mixed population of healthy/unhealthy females. The studies reported conflicting results: no impact, positive impact (multiparity is associated with larger forced-expiratory-volume in one second, forced- and slow- vital-capacity, and inspiratory-capacity), or negative impact (multiparous females has lower bronchial flows, higher static volumes, an accelerated lung-aging, a tendency to an obstructive-ventilatory-defect and/or to lung-hyperinflation, and increased protease inhibitor levels).Expert opinion: The ten studies presented some limitations that made data interpretation relatively difficult. Future research to identify the 'real' impact of parity on spirometric parameters are therefore encouraged.

Plethysmographic data and profile of North-African patients with severe obstructive sleep apnea treated with continuous positive airway pressure

OBJECTIVES

In obstructive sleep apnea (OSA) patients, the frequencies of the different ventilatory defects are unknown and the studies examining their plethysmographic profiles and/or pulmonary function test data have contradictory results. The main aim of this prospective study was to establish the plethysmographic profile of severe OSA patients treated with continuous positive airway pressure (CPAP).

METHODS

100 (33 females) clinically consecutive stable patients with severe OSA treated with CPAP were included. Anthropometric, polysomnographic, and pulmonary function test data were collected. The following definitions were applied: large airways obstructive ventilatory defect (LAOVD): (FEV₁/SVC or FEV₁/FVC < lower limit of normal (LLN), small airways obstructive ventilatory defect (SAOVD): (FEV₁/FVC and FVC) > LLN and maximal mid-expiratory flow (MMEF) < LLN, restrictive ventilatory defect (RVD): total lung capacity (TLC) < LLN, lung-hyperinflation: residual volume > upper limit of-normal, and nonspecific ventilatory defect (NSVD): (FVC and FEV₁) < LLN and TLC > LLN and (FEV₁/SVC or FEV₁/FVC) > LLN.

RESULTS

The plethysmographic profile of OSA patients included RVD (73%), SAOVD (50%), LAOVD (16%), mixed-VD (11%), lung-hyperinflation (11%), and NSVD (2%).

CONCLUSION

The plethysmographic profile of OSA patients was dominated by the presence of an RVD.

Lung Function Testing and Prediction Equations in Adult Population from Maputo, Mozambique

Background: Local spirometric prediction equations are of great importance for interpreting lung function results and deciding on the management strategies for respiratory patients, yet available data from African countries are scarce. The aim of this study was to collect lung function data using spirometry in healthy adults living in Maputo, Mozambique and to derive first spirometric prediction equations for this population. Methods: We applied a cross-sectional study design. Participants, who met the inclusion criteria, underwent a short interview, anthropometric measurements, and lung function testing. Different modelling approaches were followed for generating new, Mozambican, prediction equations and for comparison with the Global Lung Initiative (GLI) and South African equations. The pulmonary function performance of participants was assessed against the different reference standards. Results: A total of 212 males and females were recruited, from whom 155 usable spirometry results were obtained. The mean age of participants was 35.20 years (SD 10.99) and 93 of 155 (59.35%) were females. The predicted values for forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and the FEV1/FVC ratio based on the Mozambican equations were lower than the South African—and the GLI-based predictions. Conclusions: This study provides first data on pulmonary function in healthy Mozambican adults and describes how they compare to GLI and South African reference values for spirometry.

The impacts of parity on lung function data (LFD) of healthy females aged 40 years and more issued from an upper middle income country (Algeria): A comparative study

BACKGROUND

Studies evaluating the impacts of parity on LFD of healthy females presented controversial conclusions.

AIM

To compare the LFD of healthy females broken down according to their parities.

METHODS

A medical questionnaire was administered and anthropometric data were determined. Two groups [G1 (n = 34): ≤ 6; G2 (n = 32): > 6] and three classes [C1 (n = 15): 1-4; C2 (n = 28): 5-8; C3 (n = 23): 9-14] of parities were identified. LFD (plethysmography, specific airway resistance (sRaw)] were determined. Student's t-test and ANOVA test with post-Hoc test were used to compare the two groups' and the three classes' data.

RESULTS

G1 and G2 were age and height matched; however, compared to G1, G2 had a lower body mass index (BMI). C1, C2 and C3 were height, weight and BMI matched; however, compared to C2, C3 was older. G1 and G2 had similar values of FEV1, forced- and slow- vital capacities (FVC, SVC), maximal mid-expiratory flow (MMEF), forced expiratory flow at x% of FVC (FEFx%), peak expiratory flow (PEF), expiratory and inspiratory reserve volumes (ERV, IRV, respectively), inspiratory capacity (IC), sRaw, FEV1/FVC, FEV1/SVC, and residual volume/total lung capacity (RV/TLC). The three classes had similar values of MMEF, FEFx%, PEF, thoracic gas volume (TGV), ERV, IRV, FEV1/FVC, FEV1/SVC and RV/TLC. Compared to G1, G2 had higher TGV (2.68±0.43 vs. 3.00±0.47 L), RV (1.80±0.29 vs. 2.04±0.33 L) and TLC (4.77±0.62 vs. 5.11±0.67 L). Compared to C1, C2 had higher FEV1 (2.14±0.56 vs. 2.47±0.33 L), FVC (2.72±0.65 vs. 3.19±0.41 L), SVC (2.74±0.61 vs. 3.24±0.41 L), TLC (4.47±0.59 vs. 5.10±0.58 L), IC (1.92±0.41 vs. 2.34±0.39 L) and sRaw (4.70±1.32 vs. 5.75±1.18 kPa*s). Compared to C1, C3 had higher TLC (4.47±0.59 vs. 5.05±0.68 L) and RV (1.75±0.29 vs. 2.04±0.30 L).

CONCLUSION

Increasing parity induced a tendency towards lung-hyperinflation.

Relationship between symptomatic pelvic organ prolapse and respiratory muscle strength in middle-aged and older women in Northeast Brazil: a cross-sectional study

Some respiratory muscles work in synergy with the pelvic floor (PF). Pelvic organ prolapse (POP) is characterized by weak PF muscles and has been associated with worse pulmonary ventilation function in women. To date no studies have investigated the association between respiratory muscle strength and POP. This study aimed to determine whether symptomatic POP is associated with respiratory muscle strength in middle-aged and older women. In this observational cross-sectional study, 204 community-dwelling women (41-80 years old) from Santa Cruz (Northeastern Brazil) provided information on socioeconomic characteristics, health behavior, reproductive history and symptomatic POP via a structured questionnaire. A digital manometer was used to measure their maximal inspiratory and expiratory pressures (MIP and MEP). Multiple linear regression analyses, adjusted for covariates (age, income, education, body mass index, and smoking), evaluated the association between POP and MIP/MEP. The results show that 14.7% of the sample reported symptomatic POP. These women exhibited lower mean MIP and MEP than those reporting no POP, but the intergroup difference was only significant for MEP (p = .01). The association between POP and MEP remained statistically significant, even after covariates (β = 11.9, p = .04) were adjusted. Symptomatic POP is associated with expiratory muscle strength in middle-aged and older women. This innovative research provides important information regarding the need to evaluate the integrity of PF muscles when assessing respiratory muscle strength, which may help clinicians devise preventive and treatment strategies to improve women's health during the aging process.

Relationship between maximal respiratory pressures and multiple childbearing in Brazilian middle-aged and older women: A cross-sectional community-based study

Objective

Previous studies show that multiparity and a number of chronic conditions are correlated among women. Also, low respiratory muscle strength has been associated to adverse health outcomes such as chronic lung disease and early mortality. This study aimed to investigate associations between the number of lifetime pregnancies and maximal inspiratory/expiratory pressures.

Methods

In a cross-sectional study, 204 women ages 41–80 years-old, from the rural community of Santa Cruz, Brazil, provided data regarding demographics, socioeconomic characteristics, health behaviors, and number of lifetime pregnancies (≤3, 4–6 or ≥7). Maximal respiratory pressures were measured with a digital manometer. Multiple linear regression analysis was used to examine the association of multiple childbearing on maximal respiratory pressures.

Results

Of the participants, 44.1% had ≤3 pregnancies, 30.4% had 4–6 pregnancies and 25.5% had >7 pregnancies. In the unadjusted analyses, maximal inspiratory and expiratory pressures varied significantly according to multiple childbearing categories. After adjustment, the values remained statistically significant only for maximal expiratory pressure. Compared to women with ≤3 lifetime pregnancies, those who had ≥7 pregnancies had significantly lower maximal expiratory pressure values (β = -18.07, p = 0.01)

Conclusion

Multiple childbearing appears to be negatively associated with maximal respiratory pressures; women with a higher number of lifetime pregnancies had lower values of maximal respiratory pressures when compared to those with fewer pregnancies. This association may be due to biomechanical changes in the respiratory muscles promoted by multiple lifetime pregnancies. This finding indicates a need to motivate women, from the prenatal to postpartum period, to safely exercise their respiratory muscles, including abdominal muscle exercises as well as respiratory muscle training.

The multi-ethnic global lung initiative 2012 (GLI-2012) norms reflect contemporary adult's Algerian spirometry

Background

The validation of the multi-ethnic GLI-2012 spirometric norms has been debated in several countries. However, its applicability in Algeria has not been verified.

Aim

To ascertain how well the GLI-2012 norms fit contemporary adult Algerian spirometric data.

Methods

This was a cross-sectional study of a convenience sample of 300 healthy non-smoker adults (50% men, age range: 18–85 years) recruited from the Algiers region general population. All participants underwent a clinical examination and a plethysmography measurement. Z-scores for some spirometric data [FEV₁, FVC, FEV₁/FVC and forced expiratory flow at 25–75% of FVC (FEF_25-75%)] were calculated. If the average Z-score deviated by “< ± 0.5” from the overall mean, the GLI-2012 norms would be considered as reflective of contemporary Algerian spirometry.

Results

The means±SDs of age, height, weight, FVC, FEV₁, FEV₁/FVC and FEF_25-75% of the participants were, respectively, 48±17 years, 1.65±0.10 m, 73±14 kg, 4.04±1.04 L, 3.18±0.82 L, 0.79±0.05 and 4.09±1.09 L/s. Almost the quarter of participants were obese. The total sample means±SDs Z-scores were 0.22±0.87 for FVC, 0.04±0.88 for FEV₁, -0.34±0.67 for FEV₁/FVC and 0.93±0.79 for FEF_25-75%. For men and women, only the means±SDs of the FEF_25-75% Z-scores exceeded the threshold of “± 0.5”, respectively, 1.13±0.77 and 0.73±0.76.

Conclusion

Results of the present study, performed in an Algerian population of healthy non-smoking adults, supported the applicability of the GLI-2012 norms to interpret FEV₁, FVC and FEV₁/FVC but not the FEF_25-75%.

Physical inactivity, gender and culture in Arab countries: a systematic assessment of the literature

Background

Physical inactivity is associated with excess weight and adverse health outcomes. We synthesize the evidence on physical inactivity and its social determinants in Arab countries, with special attention to gender and cultural context.

Methods

We searched MEDLINE, Popline, and SSCI for articles published between 2000 and 2016, assessing the prevalence of physical inactivity and its social determinants. We also included national survey reports on physical activity, and searched for analyses of the social context of physical activity.

Results

We found 172 articles meeting inclusion criteria. Standardized data are available from surveys by the World Health Organization for almost all countries, but journal articles show great variability in definitions, measurements and methodology. Prevalence of inactivity among adults and children/adolescents is high across countries, and is higher among women. Some determinants of physical inactivity in the region (age, gender, low education) are shared with other regions, but specific aspects of the cultural context of the region seem particularly discouraging of physical activity. We draw on social science studies to gain insights into why this is so.

Conclusions

Physical inactivity among Arab adults and children/adolescents is high. Studies using harmonized approaches, rigorous analytic techniques and a deeper examination of context are needed to design appropriate interventions.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5472-z) contains supplementary material, which is available to authorized users.

Defining obstructive ventilatory defect in 2015

INTRODUCTION

There is no clear consensus as to what constitutes an obstructive ventilatory defect (OVD): Is it FEV1/FVC

AIM

To determine, according to the two definitions, the percentage of subjects having an OVD among them explored in a lung function exploration laboratory.

POPULATION AND METHODS

This is a retrospective study including 4,730 subjects aged 17-85 years. Subjects were divided according to the presence [physio (+) or operat (+)] or absence [physio (-) or operat (-)] of an OVD, and into younger (<45 years, n=2,076), older (≥45 years, n=2,654), smokers (n=1,208), and non-smokers (n=3,522) groups.

RESULTS

For the total sample, the younger and older groups [mean±SD of age (years), respectively, 46.7±14.1; 33.9±7.4, and 56.8±9.1], the 'physiological definition' detected, respectively, 13.46, 43.22, and 5.09% more OVD than the 'operational one' (p<0.05). In addition, the operational definition, compared with the physiological one, overdiagnosed OVD in 2.33 and 0.44% of smokers and non-smokers, respectively, and underdiagnosed it in 4.46% and 29.72% of smokers and non-smokers, respectively (p<0.05). Compared with the group 'physio (-), operat (+)', the 'physio (+), operat (-)' one was younger (74.2±4.7 years vs. 40.9±10.3 years) and had significantly higher FEV1 (62±13% vs. 78±17%) and FVC (71±15% vs. 93±19%).

CONCLUSION

The frequency of OVD much depends on the criteria used for its definition.

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Key Words

• FEV1/FVC
• fixed threshold
• guideline
• lower limit of normal
• obstructive ventilatory defect
• spirometry

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MESH Headings

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Female
• Forced Expiratory Volume
• Humans
• Male
• Middle Aged
• Pulmonary Disease, Chronic Obstructive/diagnosis
• Pulmonary Disease, Chronic Obstructive/epidemiology
• Pulmonary Disease, Chronic Obstructive/physiopathology
• Respiratory Function Tests
• Retrospective Studies
• Smoking/adverse effects
• Smoking/physiopathology
• Spirometry/methods
• Tunisia/epidemiology
• Vital Capacity

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Affiliation(s)

Zied Affes Department of Physiology and Functional Exploration, Farhat HACHED University Hospital of Sousse, Sousse, Tunisia
Salaheddine Rekik Department of Physiology and Functional Exploration, Farhat HACHED University Hospital of Sousse, Sousse, Tunisia
Helmi Ben Saad Department of Physiology and Functional Exploration, Farhat HACHED University Hospital of Sousse, Sousse, Tunisia Laboratory of Physiology, Faculty of Medicine of Sousse, University of Sousse, Sousse, Tunisia Research Laboratory N° LR14ES05: Interactions of the Cardiopulmonary System, Faculty of Medicine of Sousse, University of Sousse, Sousse, Tunisia;

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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.

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

Aims. To establish Fe_NO 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 Fe_NO 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 Fe_NO. Results. 257 adults (145 males) were retained. The proposed reference equation to predict Fe_NO value is lnFe_NO (ppb) = 3.47−0.56× height (m). After the predicted Fe_NO 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 Fe_NO (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 Fe_NO 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 Fe_NO higher than 26.00 ppb. Conclusion. The present Fe_NO norms enrich the global repository of Fe_NO norms that the clinician can use to choose the most appropriate norms.

The recent multi-ethnic global lung initiative 2012 (GLI2012) reference values don't reflect contemporary adult's North African spirometry

BACKGROUND

The applicability of the recent multi-ethnic reference equations derived by the ERS Global Lung Initiative (ERS/GLI) in interpreting spirometry data in North African adult subjects has not been studied.

OBJECTIVE

To ascertain how well the recent ERS/GLI reference equations fit contemporary adult Tunisian spirometric data.

POPULATION AND METHODS

Spirometric data were recorded from 1192 consecutive spirometry procedures in adults aged 18-60 years. Reference values and lower limits of normality (LLN) were calculated using the local and the ERS/GLI reference equations. Applied definitions: large airway obstructive ventilatory defect (LAOVD): FEV1/FVC < LLN. Tendency to a restrictive ventilatory defect (TRVD): FEV1 and FVC < LLN and FEV1/FVC ≥ LLN. The spirometric profile, according to the two reference equations, was determined. Z-scores for spirometry from North African healthy subjects (n = 489) were calculated. If the average Z-score deviated by <± 0.5 from the overall mean, the ERS/GLI reference equations would be considered as reflective of contemporary Tunisian spirometry.

RESULTS

Using Tunisian reference equations, 71.31%, 6.71% and 19.04% of spirometry records were interpreted as normal, and as having, LAOVD and TRVD, respectively. Using the ERS/GLI reference equations, these figures were respectively, 85.82%, 4.19% and 8.39%. The mean ± SD Z-scores for the contemporary healthy North African subject's data were -0.55 ± 0.87 for FEV1, -0.62 ± 0.86 for FVC and 0.10 ± 0.73 for FEV1/FVC.

CONCLUSION

The present study don't recommend the use of the recent ERS/GLI reference equations to interpret spirometry in North African adult population.

Multi-ethnic reference values for spirometry for the 3-95-yr age range: the global lung function 2012 equations

The aim of the Task Force was to derive continuous prediction equations and their lower limits of normal for spirometric indices, which are applicable globally. Over 160,000 data points from 72 centres in 33 countries were shared with the European Respiratory Society Global Lung Function Initiative. Eliminating data that could not be used (mostly missing ethnic group, some outliers) left 97,759 records of healthy nonsmokers (55.3% females) aged 2.5-95 yrs. Lung function data were collated and prediction equations derived using the LMS method, which allows simultaneous modelling of the mean (mu), the coefficient of variation (sigma) and skewness (lambda) of a distribution family. After discarding 23,572 records, mostly because they could not be combined with other ethnic or geographic groups, reference equations were derived for healthy individuals aged 3-95 yrs for Caucasians (n=57,395), African-Americans (n=3,545), and North (n=4,992) and South East Asians (n=8,255). Forced expiratory value in 1 s (FEV(1)) and forced vital capacity (FVC) between ethnic groups differed proportionally from that in Caucasians, such that FEV(1)/FVC remained virtually independent of ethnic group. For individuals not represented by these four groups, or of mixed ethnic origins, a composite equation taken as the average of the above equations is provided to facilitate interpretation until a more appropriate solution is developed. Spirometric prediction equations for the 3-95-age range are now available that include appropriate age-dependent lower limits of normal. They can be applied globally to different ethnic groups. Additional data from the Indian subcontinent and Arabic, Polynesian and Latin American countries, as well as Africa will further improve these equations in the future.

Six-minute walk test in non-insulin-dependent diabetes mellitus patients living in Northwest Africa

INTRODUCTION

International recommendations of the exploration of non-insulin-dependent diabetes mellitus (NIDDM) are focused on deficiency and not incapacity.

AIMS

(1) To estimate the incapacity of NIDDM patients through the 6-minute walk test (6MWT) data. (2) To determine their 6-minute walk distance (6MWD) influencing factors (3) To compare data of NIDDM patient group (PG; n = 100) with those of two control groups (CG): CG1 (n = 174, healthy nonobese and nonsmoker); CG2 (n = 55, obese nondiabetic free from comorbidities).

POPULATION AND METHODS

The anthropometric, socioeconomic, clinical, metabolic, and 6MWT data of 100 NIDDM patients (45 females) were collected.

RESULTS

Total sample means ± standard deviation of age, weight, and height were 54 ± 8 years, 81 ± 14 kg, and 1.64 ± 0.09 m. (1) Measured 6MWD (566 ± 81 m) was significantly lower than the theoretical 6MWD (90% ± 12%). The profile of the PG carrying the 6MWT, was as follows: 23% had an abnormal 6MWD; at the end of the 6MWT, 21% and 12% had, respectively, a low heart rate and a high dyspnea (>5/10), and 4% had desaturation during the walk. The estimated "cardiorespiratory and muscular chain" age (68 ± 16 years) was significantly higher than the chronological age. (2) The factors that significantly influenced the 6MWD (r(2) = 0.58) are included in the following equation: 6MWD (m) = -73.94 × gender (0, male; 1, female) - 3.25 × age (years) + 7.33 × leisure activity score - 35.57 × obesity (0, no; 1, yes) + 32.86 × socioeconomic level (0, low; 1, high) - 27.67 × cigarette use (0, no; 1, yes) + 8.89 × resting oxyhemoglobin saturation - 105.48. (3) Compared to the CGs, the PG had a significantly (P < 0.05) lower 6MWD (100%+9% and 100%+8%, respectively, for the CG1 and CG2).

CONCLUSION

NIDDM seems to accelerate the decline of the submaximal aerobic capacity evaluated through the 6MWD.

North African reference equation for peak nasal inspiratory flow

AIM

To assess, in healthy North African subjects, the applicability and reliability of a previously published reference equation and normal values for peak nasal inspiratory flow, and to calculate a peak nasal inspiratory flow reference equation in this population.

SUBJECTS AND METHODS

Anthropometric data were recorded in 212 volunteers (100 females and 112 males) aged 13-27 years. Peak nasal inspiratory flow was measured several times. Univariate and multiple linear regression analyses were used to determine the reference equation.

RESULTS

The previously published reference equation and normal values did not reliably predict peak nasal inspiratory flow in the study population. In our subjects, the reference equation (r2 = 30 per cent) for peak nasal inspiratory flow (l/min) was 1.4256 × height (m) + 33.0215 × gender (where 0 = female, 1 = male) + 1.4117 × age (years) - 136.6778. The lower limit of normal was calculated by subtracting from the peak nasal inspiratory flow reference value (84 l/min).

CONCLUSION

This is the first published study to calculate a reference equation for peak nasal inspiratory flow in North African subjects. This equation enables objective evaluation of nasal airway patency in patients of North African origin.

[Determining factors of pulmonary function in healthy Tunisian children]

Introduction Pulmonary function parameters are known to vary with age, sex, height and ethnic extraction. No normal values have been reported for pulmonary function in Tunisian children. Moreover, little attention has been paid to the factors affecting the development of lung function in Tunisian healthy children. State of art Birth weight and height, physical activity level, anthropometric, socioeconomic and environmental factors could influence the development of lung function in healthy children. Perspectives The studies conducted by our group have allowed us 1) to set reference values for spirometry in healthy Tunisian children; 2) to indicate that, in Tunisian adolescents, the use of only one morphological parameter such as height, is not sufficient, but the pubertal status could be taken into account to standardize the lung function and 3) to show the main predictive factors for pulmonary development to be the anthropometric factors such as height, weight, maximal inspiratory and expiratory thoracic perimeter, sex and age, and the environmental conditions (type of heating) in our population of healthy Tunisian children. Conclusion These findings should improve medical surveillance of respiratory diseases, stipulation of preventive and therapeutic measures in Tunisian children.

[Spirometric reference equations for Algerians aged 19 to 73 years]

INTRODUCTION

The validity of using European reference equations in the interpretation of spirometry results in Algerian patients has not been assessed.

AIMS

(i) to establish Algerian spirometric reference equations and (ii) to compare them with European ones.

METHODS

A medical questionnaire was administered. Gender, age, height, weight, lean mass (LM), percentage of fat mass (%FM) and body mass index (BMI) were noted. Spirometric variables were measured using a body plethysmograph according to international guidelines. Simple and multiples linear regressions were performed. The measured forced expiratory volume (FEV1), forced vital capacity (FVC) and the ratio between FEV1 and slow vital capacity (FEV1/SVC) were compared with those predicted from European reference equations.

RESULTS

273 healthy subjects (120 women) were included (age: 42+/-14 years; height: 1.69+/-0.10 m; weight: 74+/-13 kg; LM: 59+/-10 kg;%FM: 21+/-6%; BMI: 26+/-6 Kg.m-2). (i) Algerian reference equations explained 17% to 68% of the variability of parameters tested. (ii) The European reference equations significantly underestimated the measured FEV1, FVC and the FEV1/SVC ratio (respectively, 0.38+/-0.45 L, 0.36+/-0.55 L, and 0.01+/-0.06).

CONCLUSION

The use of Algerian spirometric reference equations should improve the accuracy of lung function interpretation in this population.

[Which definition to use when defining airflow obstruction?]

INTRODUCTION

There is no clear consensus as to what constitutes an obstructive ventilatory defect (OVD). According to the American Thoracic Society and European Respiratory Society, it is defined as being when the ratio of the forced expiratory volume (FEV1) and the slow expiratory vital capacity (VC) is below the lower limit of normal (LLN). According to the Global initiative for chronic Obstructive Lung Disease and the British Thoracic Society, it is an FEV1/forced expiratory vital capacity (FVC)<0.70 and an FEV1<80%. In addition, in daily practice, the OVD is diagnosed by a "Fixed ratio" FEV1/FVC<0.70 or<LLN. The aim of this study is to determine, according to the different recommendations, the percentage of subjects having an OVD among them addressed for suspicion of chronic obstructive pulmonary disease.

METHODS

A medical questionnaire was administered and anthropometric data were collected. The expiratory flows and pulmonary volumes were measured by a body plethysmograph.

RESULTS

121 (81%) subjects among the 150 examined were included. The percentage of subjects having an OVD was 56.1% (FEV1/VC<LLN), 54.1% (FEV1/FVC<0.70), 48.7% (FEV1/FVC<0.70 and FEV1<80%), and 47.8% (FEV1/FVC<LLN).

CONCLUSION

The prevalence of obstructive ventilatory defect in a population depends on the definition chosen.