Lung function (exhaled air volume)

Pulmonary function is an indicator of the physiological state of the airways and lungs, and plays an essential role in the diagnosis and monitoring of respiratory diseases, such as chronic obstructive pulmonary disease (COPD). When assessing lung function, spirometry is the most widely used test. This technique measures important parameters such as forced vital capacity (FVC).

Pulmonary function testing plays an important role in diagnosing and monitoring patients with suspected or previously diagnosed respiratory disease. In fact, these tests are a fundamental criterion in the diagnosis of diseases such as chronic obstructive pulmonary disease (COPD). They are also crucial prior to significant surgical procedures and for assessing response to treatment in cases of chronic respiratory disease.

There are several tests designed to assess lung function, such as the carbon monoxide diffusion test, whole-body plethysmography, bronchoprovocation test and the 6-minute walk test. However, spirometry is the most commonly used test. This technique consists of a deep, full inspiration followed by a rapid, forced exhalation. Through spirometry, several parameters can be measured, including the peak expiratory volume in the first second (MASV or FEV1), the forced vital capacity (FVC or FVC) and the ratio between these volumes (FEV1/FVC).

FVC represents the maximum amount of air that a person can forcibly exhale after a full inhalation, with a normal value ≥ 80 %. FEV1, on the other hand, measures the amount of air exhaled in the first second after a deep inhalation, and its normal value is also ≥ 80 %. Finally, the FEV1/FVC index expresses the fraction of air exhaled in one second in relation to the forced vital capacity, and its normal value is ≥ 70 %.

These parameters are crucial for identifying defects in lung function, whether of the obstructive type, as in the case of diseases such as chronic obstructive pulmonary disease (COPD) or asthma; or of the restrictive type, as in idiopathic pulmonary fibrosis.

Our analysis focuses on the study of genetic variants related to forced vital capacity. Non-genetic risk factors related to decreased FVC levels include ethnicity, obesity, diabetes, tobacco use and the presence of chronic respiratory symptoms.

As a consequence, preventive measures to maintain forced vital capacity at adequate levels focus on adopting a healthy lifestyle. This involves following a balanced diet, exercising regularly and abstaining from tobacco use, which contributes significantly to preserving lung function and reducing the risk of respiratory disorders.