Introduction:

Spirometry is a lung function test used in the evaluation of rehabilitation programs to evaluate exposures to toxics and allergens in epidemiological studies and in the development of reference equations in specific populations; these values may vary according to height.

Objective:

To establish the differences between the reference values of forced spirometry in the adult population living at altitudes greater than and less than 1,500 meters above sea level.

Methods:

Systematic review a total of 536 studies were found; 66 were assessed in full text and 33 were assessed for methodological quality using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and Quality Assessment of Case-Control Studies checklists; 21 studies were selected for the review and 12 provided meta-analyses.

Results:

There were 48,923 participants from heights between 2.4 and 4,440 m.a.s.l. There are initial differences when relating height (+/-1,500 m.a.s.l.) with FEV1 (men: MD 0.29; CI: 0.03-0.55; women: MD 0.27; CI: -0.07-0 .60); and the reference values with gender: FVC (MD 1.31, CI: 1.24-1.37) and FEV1 (MD: 1.03, CI: 0.95-1.11). High heterogeneity and risk of publication bias are reported.

Discussion:

These differences occur based on anthropometric and physiological aspects such as acclimatization and lung aging. The mechanisms that influence these changes are genetic, molecular, physiological and anatomical adaptations that allow compensation for the effects of acute or chronic hypoxia, which increases alveolar ventilation and spirometric values.

Conclusions:

The spirometry reference values vary according to height (higher at heights >1,500 m.a.s.l.) and sex (higher in men). It is necessary to have broader and more convincing evidence on the subject.