Exploring the Link Between Physical Activity and Preserved Ratio Impaired Spirometry: Key Insights for Lung Health

Background

Physical activity refers to body movement that utilizes skeletal muscles, leading to increased energy expenditure above resting levels. Studies show that regular physical activity reduces the risk of various diseases, including cardiovascular disease, stroke, diabetes, obesity, certain cancers, and depression. Additionally, people who engage in more physical activity tend to experience less decline in lung function. While physical exercise may influence the prognosis of Preserved Ratio Impaired Spirometry (PRISm), it is unclear if different activity levels can reduce PRISm risks. This study aimed to examine the relationship between physical activity and PRISm using national data.

Materials and Methods

Study Design and Population

Participants from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2012, aged 6 to 79, completed spirometry tests following American Thoracic Society guidelines. Lung function was categorized using spirometry data.

Assessment of Spirometry

Participants were assessed using post-bronchodilator spirometry to categorize lung function into PRISm. PRISm was defined as forced expiratory volume (FEV1) to forced vital capacity (FVC) ratio of 0.7 or greater with specific FEV1 and FVC criteria.

Assessment of Physical Activity

The Global Physical Activity Questionnaire (GPAQ) collected data on weekly physical activity levels. Activity was measured in metabolic equivalents (METs), with vigorous activities assigned 8 METs and moderate activities 4 METs. Participants’ physical activity was categorized into four quartiles based on annual activity levels.

Assessment of Covariates

Data on demographic and health factors, including age, gender, hypertension, diabetes, cardiovascular disease, education level, and lifestyle habits, were collected through a structured questionnaire.

Statistical Analysis

Data were analyzed as continuous or categorical variables. Appropriate methods were used for each analysis type, including variance analysis, logistic regression, and trend analysis. Weighted analyses were vital to account for the NHANES sampling design.

Results

From the NHANES data spanning 2007 to 2012, 17,713 individuals aged 20 and above participated. Eventually, 13,387 individuals contributed valid data on lung function and physical activity. Participants were categorized into three groups based on lung function: PRISm, Chronic Obstructive Pulmonary Disease (COPD), and normal lung function.

The PRISm group had notably higher proportions of older individuals and male participants. This group also displayed higher previous or current smoking rates, higher rates of diabetes, and hypertension. Lower educational attainment and reduced physical activity levels were more common among PRISm individuals compared to others.

Univariate logistic regression revealed factors associated with a lower risk of PRISm. These included being female, higher education levels, lower poverty impact ratios, abstaining or lower alcohol use, and lower cholesterol levels. Conversely, age over 65, higher BMI, ethnicity, smoking, diabetes, hypertension, and cardiovascular disease linked to a higher risk of PRISm.

Physical activity levels in quartiles showed a lower risk of PRISm for those in higher activity categories. Statistical analyses indicated a significant trend of reduced PRISm risk associated with increased physical activity.

A significant nonlinear negative dose-response relationship was found between physical activity levels and PRISm risk. The physical activity benefits were evident with stratification by sex and BMI. Increased physical activity correlated with lower PRISm risk in both men and women and in those with a BMI of 25 or more.

Discussion

This study is the first to illustrate the link between varying physical activity levels and PRISm risk. Increased physical activity correlates with a reduced risk of PRISm, particularly in individuals with a BMI of 25 or higher. The identified dose-response relationship is vital for public health considerations.

Limitations

This study is retrospective. Results may reflect inherent biases of retrospective research. The reliance on self-reported physical activity could also introduce data inaccuracies. Further, the study’s sample size may limit its findings concerning individuals with varying BMIs.

Conclusion

Higher physical activity levels are linked to a lower risk of PRISm, especially in those with a BMI of 25 or more. The significant negative dose-response relationship highlights the importance of regular physical activity. More prospective research is needed to understand these associations and their causal connections.