Association between pulmonary ventilation function and cognitive function among middle-aged and older adults: an observational study from Southwest China

Abstract

Background: Despite the significant prevalence of chronic obstructive pulmonary disease (COPD) in Southwest China, cognitive function among middle-aged and elderly individuals in this area surpasses the national average. This study aims to reveal the overall pulmonary ventilation function status of this population, and investigate whether pulmonary ventilation dysfunction is a risk factor for mild cognitive impairment (MCI) in this region, as suggested by previous researches.

Methods: Data were obtained from the 2019-2021 baseline survey of a natural population cohort study conducted in Southwest China. Pulmonary function was tested by experienced and well-trained medical personnel using a spirometer. The Mini-Mental State Examination was used to evaluate cognitive function. Subsequently, multiple logistic regression analysis was employed to examine the associations between pulmonary function and cognitive levels.

Results: A total of 2,337 middle-aged and elderly adults were included in this study, with 10.18% (238 individuals) classified as having mild cognitive impairment. According to the Chinese experts' consensus on the standardization of adult lung function diagnosis, approximately 41.16% (962/2,337) of middle-aged and elderly individuals in Southwest China suffer from pulmonary ventilation dysfunction, predominantly mild (37.53%, 877/2,337), with the primary type being obstructive ventilation dysfunction (38.60%, 902/2,337; COPD: 14.21%, 332 participants). And 81.56% participants (1,906/2,337) were found to have small airway dysfunction. Multiple logistic regression analyses showed that individuals with poor pulmonary ventilation function (PPF) were associated with an increased risk of MCI (OR [95% CI]: 1.38 [1.04, 1.83], P = 0.026). Moreover, the more severe the pulmonary ventilation dysfunction, the higher the risk of cognitive impairment (P for trend = 0.009). Similar association were found between PPF and MCI when we use ATS/ERS technical standards. No significant association was observed between small airway dysfunction and cognitive impairment (OR [95% CI]: 1.05 [0.72, 1.56], P = 0.819).

Conclusions: The pulmonary function status of middle-aged and elderly individuals in Southwest China requires attention, particularly regarding obstructive pulmonary ventilation dysfunction. We recommend integrating pulmonary health assessments into routine care for these populations to raise awareness of lung health, improve lung function, and ultimately enhance cognitive function.

Keywords: Cognitive function; Lung function; Mild cognitive impairment; Pulmonary ventilation function.

Fig. 1

Characteristics of pulmonary ventilation function of the study participants (classified according to Chinese expert consensus). a. Distribution of pulmonary function status in study participants. b. Severity distribution of pulmonary function impairment. c. Distribution of small airway dysfunction prevalence. d. Distribution of COPD (FEV1/FVC < 0.7) status. NPF, normal pulmonary function; PPF, poor pulmonary function; PPF-obstructive, obstructive ventilatory dysfunction; PPF-restrictive, restrictive ventilatory dysfunction; PPF-mixed, mixed ventilatory dysfunction

Fig. 2

Subgroup analysis. All models were adjusted for education level, BMI, history of dyslipidemia, and (where appropriate) gender, and history of respiratory diseases. NPF, normal pulmonary function; PPF, poor pulmonary function