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.


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.


CONCLUSIONS
The present study don't recommend the use of the recent ERS/GLI reference equations to interpret spirometry in North African adult population.
Functional Exploration Laboratory, Occupational Medicine Group of Sousse, Tunisia; Research Unit: prevention secondaire après infarctus du myocarde, N: 04/UR/08-18, Faculty of Medicine of Sousse, Sousse, Tunisia; Laboratory of Physiology, Faculty of Medicine, University of Sousse, Tunisia; Department of Physiology and Functional Explorations, Farhat HACHED Hospital, Sousse, Tunisia. Electronic address: helmi.bensaad@rns.tn.
Helmi
H
Ben Saad
Mohamed Nour
MN
El Attar
Khaoula
K
Hadj Mabrouk
Ahmed
A
Ben Abdelaziz
Ahmed
A
Abdelghani
Mohamed
M
Bousarssar
Khélifa
K
Limam
Chiraz
C
Maatoug
Hmida
H
Bouslah
Ameur
A
Charrada
Sonia
S
Rouatbi
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000462:Algeria / Q000208:ethnology; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D017678:Sex Distribution; D013147:Spirometry / Q000592:standards; D014416:Tunisia / Q000208:ethnology; D014797:Vital Capacity / Q000502:physiology; D044465:White People / Q000208:ethnology*; D055815:Young Adult
Caucasian race; Ethnic groups; North Africa; Reference values; Spirometry