Peak Expiratory Flow and the Risk of Injurious Falls in Older Adults: The Role of Physical and Cognitive Deficits

Lung function in relation to brain aging and cognitive transitions in older adults: A population-based cohort study

BACKGROUND

We investigated the association of peak expiratory flow (PEF) with dementia; cognitive impairment, no dementia (CIND); and transition from CIND to dementia, and possible underlying neuropathological mechanisms.

METHODS

A population-based cohort of adults aged 60+ was followed over 15 years to detect dementia (Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria), CIND (assessed through a cognitive battery), and progression from CIND to dementia, in relation to baseline PEF observations. A subsample (n = 462) had 6-year follow-up data on brain magnetic resonance imaging markers of neurodegeneration and small vessel disease.

RESULTS

In fully adjusted models, poor PEF performance (< 10th vs. ≥ 80th percentile) was associated with increased hazards for dementia (hazard ratio [HR] = 1.89; 95% confidence interval [CI] = 1.23-2.92) and CIND (HR = 1.55; 95% CI = 1.01-2.38) and CIND progression to dementia, although not statistically significantly (HR = 2.44; 95% CI = 0.78-6.88). People with poor PEF also experienced the fastest ventricular enlargement (β coefficient = 0.67 mL/year; 95% CI = 0.13-1.21) and had the highest likelihood of developing lacunes (odds ratio = 5.05; 95% CI = 1.01-25.23).

DISCUSSION

Poor lung function contributes to cognitive deterioration possibly through accelerated brain atrophy and microvascular damage.

HIGHLIGHTS

Poor lung function increased the risk of dementia and mild cognitive impairment (MCI). Poor lung function accelerated the progression from MCI to dementia. Poor lung function was linked to brain microvascular damage and global brain atrophy.

Peak Expiratory Flow Predicts Incident Dementia in a Representative Sample of U.S. Older Adults: The National Health and Aging Trends Study (NHATS)

BACKGROUND

Dementia is an increasingly important public health problem with various risk factors. Respiratory function, measured via peak expiratory flow (PEF), may be a modifiable dementia risk factor.

METHODS

We investigated the association between PEF and incident dementia in 5 935 older adults from the National Health and Aging Trends Study (NHATS) from 2011 to 2014. Baseline PEF, expressed as a standardized residual (SR) percentile, was analyzed as a predictor of incident dementia using discrete-time proportional hazards models, while controlling for several health and sociodemographic covariates.

RESULTS

After 14 332 person-years of follow-up, 9.0% (N = 536) had incident cases of dementia. Compared to the lowest PEF category (SR-percentile < 10%), the highest PEF category (SR-percentile ≥ 80%) had 49% lower risk of incident dementia (hazard ratio [HR] = 0.51; 95% confidence interval [CI; 0.37, 0.71]), and the second highest PEF category (SR-percentile 50%-80%) had 25% lower risk of incident dementia (HR = 0.75; 95% CI [0.56, 1.00]). A sensitivity analysis using multiple imputation to account for missing PEF measurements yielded similar associations with incident dementia.

CONCLUSION

These associations suggest a dose-dependent relationship such that higher PEF categories were more protective against incident dementia. PEF may be considered as an easily administered, low-cost measure of respiratory function and a potentially modifiable dementia risk factor. Improving PEF may reduce dementia risk through vascular mechanisms, such as increased brain oxygenation. Future research should explore potential causal pathways between PEF and dementia.

Effects of verbal tasks with varying difficulty on real-time respiratory airflow during speech generation in healthy young adults

Objective

Respiratory function is linked to sensory, affective, and cognitive processes and it is affected by environmental constraints such as cognitive demands. It is suggested that specific cognitive processes, such as working memory or executive functioning, may impact breathing. In turn, various lines of research have suggested a link between peak expiratory airflow (PEF) and cognitive function. However, there is scarce experimental support to the above assertions, especially regarding spoken language. Therefore, the present investigation aims to evaluate whether breathing varies as a function of performing verbal naming tasks with different difficulty levels.

Methods

Thirty healthy young adults, (age M = 25.37 years), participated in the study. Participants were required to perform aloud five verbal tasks ranged in order of difficulty: Reading single words, reading a text passage, object naming, semantic and phonemic fluency. A pneumotachograph mask was employed to acquire simultaneously the verbal responses, and three airflow parameters: Duration, peak, and volume at both stages of the respiratory cycle (i.e., inspiration/expiration). Data were analyzed with one-way repeated measures MANOVA.

Results

No significant differences were found between reading single words and object naming. In comparison, distinctive airflow requirements were found for reading a text passage, which were proportionally related to number of pronounced words. Though, the main finding of the study concerns the data on verbal fluency tasks, which not only entailed higher inhaled airflow resources but also a significant PEF.

Conclusion

Our data demonstrated that the most difficult tasks, namely semantic and phonemic verbal fluencies, relying on semantic search, executive function, and fast lexical retrieval of words were those requiring important amount of inhaled airflow and displaying a high peak expiratory airflow. The present findings demonstrated for the first time a direct association between complex verbal tasks and PEF. Inconclusive data related to object naming and reading single words are discussed in light of the methodological challenges inherent to the assessment of speech breathing and cognition in this line of investigation.

Reference Values and Related Factors for Peak Expiratory Flow in Middle-Aged and Elderly Chinese

Background: Peak expiratory flow (PEF), as an essential index used for screening and monitoring asthma, chronic obstructive pulmonary disease, and respiratory mortality especially in the elderly, is recommended for low-resource settings in low- and middle-income countries. However, few studies have focused on the reference of PEF in China, especially in middle-aged and elderly people. Thus, this study aimed to determine age- and sex-specific reference values of PEF in the middle-aged and elderly Chinese population. Methods: There were 8,914 participants who were included for risk factor analysis and 5,498 participants included for reference value analysis. The PEF was measured using a peak flow meter in liters per minute. The distributions of standardized PEF terciles stratified by sex and age were reported. Multiple linear regression analysis was used to determine the associations between risk factors and PEF. Results: The PEF was higher in men than women across all age subgroups. The value of PEF decreased with age in both men and women. Height, weight, handgrip strength, and residence in rural were positively associated with PEF. Age and smoking status were negatively associated with PEF significantly in both men and women (P < 0.05). The mean PEF values were 367.10 and 253.00 L/min for men and women, respectively. Meanwhile, the prevalence of low PEF was 3.94 and 3.32% for men and women, respectively. Conclusions: Age- and sex-specific centiles of standardized PEF for the middle-aged and elderly Chinese population were estimated. The reference values for low PEF could provide reference standards for epidemiological studies and clinical practices in the future. Interventions to improve lung functions or to prevent respiratory disease should be paid more attention to factors associated with PEF.