Obstructive spirometric pattern mainly associated with respiratory mortality

Decreased lung function is associated with reduced ventilation and oxygen intake, especially during intense activity. In addition, reduced lung function could also affect other body functions such as sleep. Spirometry is the most common type of pulmonary function or breathing test. The test measures how much air one can breathe in and out of your lungs, as well as how easily and fast you can the blow the air out of your lungs.

Even though it is well known that reduced lung function is associated with increased mortality, but it is unclear how different spirometric patterns are related to specific deaths. The current study aimed to investigate these associations in a large general population cohort of Norwegian men.

The study found that spirometric obstruction was mainly related to pulmonary mortality and particularly Spirometric restriction was mainly related to extra-pulmonary mortality. The predominant decrease in forced expiratory volume in 1 second (FEV1) is strongly associated with respiratory mortality, especially noncancer-related deaths, according to study findings published in Respiratory Medicine.

The study included a total of 26,091 men aged 30–46 years from the Pneumoconiosis Survey of Western Norway conducted in 1988–1990 with follow-up on date and cause of death for 26 years. Cox proportional hazard models were used to estimate the association between baseline FEV1, FVC, obstructive (OSP) and restrictive spirometric pattern (RSP) (z-scores calculated according to GLI-2012 equations) and mortality (European 2012 shortlist classification (E−2012)), after adjustment for age, body mass index, smoking habits, and education.

The key findings of the study are

• In total, 2462 (9%) subjects died. A predominant reduction of FEV1 (and OSP) were associated with respiratory non-cancer (E−8) (HR for one unit FEV1 z-score decrease 2.29 (95% CI 1.90, 2.77) and lung cancer mortality (E−2.1.8) (1.27(1.12, 1.44)).

• A similar reduction of FEV1 and FVC (and RSP) were associated with diabetes (E−4.1) (FEV1 2.21(1.67, 2.92), FVC 2.41(1.75, 3.32)), cerebrovascular (E−7.3) (1.52(1.21, 1.91), 1.54(1.19, 1.98)), ischemic heart disease (E−7.1) (1.22(1.10, 1.35), 1.21(1.08, 1.36))

• The same was reported for neurological (E−6.3) (1.56(1.21, 2.01), 1.61(1.22, 2.13)), suicide (E−17.2) (1.37(1.13, 1.65), 1.29(1.04, 1.59)) and hematological cancer mortality (E−2.1.19–21) (1.29(1.05, 1.58), (1.26(1.00, 1.58)).

• No association was found between reduced lung function and mortality due to accidents, alcohol abuse, digestive and genitourinary cancer.

Researchers concluded that “Spirometric obstruction was mainly related to pulmonary mortality. Spirometric restriction was mainly related to extra-pulmonary mortality.”

Reference: Lucia Cestelli, Amund Gulsvik, Ane Johannessen, Knut Stavem, Rune Nielsen et al; Reduced lung function and cause-specific mortality: A population-based study of Norwegian men followed for 26 years; Resp. med September 28, 2023 DOI:https://doi.org/10.1016/j.rmed.2023.107421