Association of Pulmonary Function With Cognitive Decline in Older Adults: A Nationwide Longitudinal Study in China

Association of peak expiratory flow with motoric cognitive risk syndrome among older adults

Background

The association between lung function and motoric cognitive risk syndrome (MCR) is unclear. We aimed to explore the association of peak expiratory flow (PEF) with MCR using cross-sectional and longitudinal analyses.

Methods

Within the CHARLS, 5095 participants were included in the cross-sectional analysis, and 4340 MCR-free participants were included in the longitudinal analysis. The PEF was assessed with a lung peak flow meter. MCR was characterized by cognitive complaints and a slow walking speed with normal mobility and without dementia. Logistic regression, Cox regression, and Laplace regression models were employed for data analysis.

Results

In this cross-sectional study, logistic regression analyses revealed that continuous PEF was associated with MCR (odds ratio [OR], 0.998; 95% confidence interval [CI], 0.998, 0.999), and the ORs (95% CIs) of MCR prevalence were 0.857 (0.693, 1.061) for the middle tertile and 0.665 (0.524, 0.845) for the highest tertile compared to the lowest tertile. In a longitudinal cohort study, continuous PEF was dose-dependently associated with the risk of MCR. Compared with those in the lowest tertile of PEF, the hazard ratios (95% CIs) of incident MCR were 0.827 (0.661, 1,036) for the middle tertile and 0.576 (0.432, 0.767) for the highest tertile. Furthermore, compared with the lowest tertile, the highest tertile was associated with a delayed onset time of MCR of 0.484 (95% CI: 0.151, 0.817) years.

Conclusion

A higher PEF was related to a lower prevalence of MCR and a lower risk for MCR, and a higher PEF also prolonged the onset time of MCR.

Nutrition intake modifies the association between pulmonary function and cognitive performance among elderly Americans from NHANES 2011-2012

PURPOSE

Nutrition intake is one of the modifiable risk factors for cognitive decline. Whether energy and protein intakes alter the association between pulmonary function (PF) and cognition has not been studied.

METHODS

We made use of information from the U.S. National Health and Nutrition Examination Survey (NHANES) 2011-2012. PF measures, including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF), were calculated, whereas cognitive function was assessed through four tests: the Immediate Recall test (IRT), the Delayed Recall test (DRT), the Animal Fluency test (AFT) and the Digit Symbol Substitution test (DSST). Energy and protein intakes were measured using the 24-h dietary recall method. Weighted generalized linear regression was performed upon adjustment for covariates. Further interaction analyses were conducted to investigate the effect of energy and protein intakes on the association between PF and cognition.

RESULTS

We finally included 803 participants aged ≥ 60 years (54.4% female, weighted value). After adjusting for covariates, multiple measures (including FEV1, FVC, PEF, and composite PF) were all positively associated with better global cognition and the DSST score (P < 0.05). A stronger positive association between the DSST score and FEV1 (P for interaction = 0.001), FVC (P for interaction = 0.004), PEF (P for interaction = 0.003), and composite PF (P for interaction = 0.001) in lower energy intake. Similar results were observed in lower protein intake (all P for interaction < 0.05).

CONCLUSION

Higher PF was independently associated with improved specific components of cognitive function (i.e., the DSST score). The positive association between PF and the DSST score was stronger in individuals with lower energy and protein intakes.

Long-term effect of extreme temperature on cognitive function of middle-aged and older adults in China

BACKGROUND

Several studies have explored the association between temperature and cognitive function. However, few studies have examined the effect of extreme temperature on cognitive function. In this study, we aimed to quantify the long-term effect of extreme temperature (e.g., heat waves, cold spells, and hot night excess (HNE)) on cognitive performance in middle-aged and older people in China.

METHOD

We investigated 7915 aged >45 years people from the China Health and Retirement Longitudinal Study (CHARLS), surveyed in 2011 and 2015. A structured questionnaire was utilized to assess cognitive function, including four dimensions: episodic memory, attention, orientation, and visuo-construction. Hourly ambient temperature from the ERA5-Land datasets were used to calculate variables indicating extreme temperature. We performed difference-in-difference (DID) models to assess the potential causal relationship between extreme temperature and cognitive function.

RESULTS

Non-linear analyses suggested that both sustained increases in temperature and excessive variability in temperature increased the risk of cognitive decline. Meanwhile, we observed the extra risk of global cognitive function decline was 2.3% (95% Confidence interval (95% CI): 0.2%, 4.4%) for heat waves (one unit increase) and 5.9% (95% CI: 0.6%, 11.6%) for HNE (one unit increase), while the association for cold spells was insignificant. Two cognitive dimensions, episodic memory and visuo-construction, were sensitive to these two heat-related factors.

CONCLUSION

Extreme temperature was inversely related to cognitive performance in middle-aged and older adults, which was substantial for heat waves and HNE particularly. The effect size varied by cognitive dimensions.

Associations of vision impairment and eye diseases with frailty in community-dwelling older adults: a nationwide longitudinal study in China

AIMS

To test whether vision impairment and major ophthalmic conditions are predictive of frailty.

METHODS

The analysis included 5321 participants aged 60-95 years at baseline from the China Health and Retirement Longitudinal Study. Participants were enrolled in 2011 and followed up in 2013, and 2015 through a face-to-face interview. Distance/near vision impairment was defined by reporting poor eyesight and reporting excellent, very good, good or fair eyesight was used as the reference. A history of cataract surgery and glaucoma were also self-reported. Frailty was defined as the presence of ≥3 of the five components of the Fried phenotype: weakness, slowness, exhaustion, inactivity and shrinking.

RESULTS

In the cross-sectional analysis, both near (odds ratio [OR] (95% confidence interval [CI]): 1.62 (1.30 to 2.00)) and distance (1.59 (1.30 to 1.96)) vision impairment was associated with a higher prevalence of frailty independent of confounders. In the longitudinal analysis, the multivariable-adjusted OR (95% CI) for incident frailty associated with glaucoma, distance vision impairment, near vision impairment and vision problem was 3.41 (1.46 to 7.99), 1.59 (1.17 to 2.17), 1.62 (1.17 to 2.23) and 2.11 (1.41 to 3.15), respectively. Vision problem was associated with decreased handgrip strength (β (95% CI): -1.47 (-2.20 to -0.75) kg) during follow-up. Individuals with glaucoma (-0.11 (-0.16 to -0.05) m/s), distance vision impairment (-0.02 (-0.03 to 0.00) m/s) or vision problem (-0.02 (-0.05 to 0.00) m/s) had decreased gait speed compared with the control group.

CONCLUSIONS

Vision problem, vision impairment and glaucoma are important predictors of frailty in older adults.

Long-Term PM2.5 Exposure, Lung Function, and Cognitive Function Among Middle-Aged and Older Adults in China

BACKGROUND

Long-term exposure to PM2.5 is related to poor lung function and cognitive impairment, but less is known about the pathway involved in this association. We aimed to explore whether the effect of PM2.5 on cognitive function was mediated by lung function.

METHODS

A total of 7 915 adults older than 45 years old were derived from the China Health and Retirement Longitudinal Study (CHARLS) collected in 2011 and 2015. PM2.5 exposure was estimated using a geographically weighted regression model. Lung function was measured by peak expiratory flow (PEF). Cognitive function was evaluated through a structured questionnaire with 4 dimensions: episodic memory, attention, orientation, and visuoconstruction. Under the counterfactual framework, causal mediation analysis was applied to examine direct and indirect associations.

RESULTS

An interquartile range (IQR) increase in PM2.5 change was significantly related to an 8.480 (95% confidence interval [CI]: 3.116, 13.845) decrease in PEF change and a 0.301 (95% CI: 0.100, 0.575) decrease in global cognitive score change. The direct and indirect effects of PM2.5 exposure on global cognitive performance were -0.279 (95% CI: -0.551, -0.060) and -0.023 (95% CI: -0.041, -0.010), respectively. The proportion of the indirect effect was 7.48% (p = .010). The same significant association appeared in only 2 dimensions, episodic memory and attention, which were both mediated by PEF.

CONCLUSIONS

Lung function played a partially mediating role in the association between long-term PM2.5 exposure and cognition. More clean air actions should be undertaken to improve lung function and cognitive function in older adults.

Association between pulmonary ventilatory function and mild cognitive impairment: A population-based study in rural China

Background

Mild cognitive impairment (MCI), a reversible intermediate state, plays an important role in the development and prevention of dementia. The relationship between pulmonary function and MCI risk has not yet been well-elucidated.

Methods

We included 2,947 rural Chinese residents aged ≥35 years who were free from a history of stroke, dementia, or other brain diseases and measured pulmonary ventilatory function using calibrated spirometry according to the recommended method. MCI was assessed with the Montreal Cognitive Assessment-Basic for Chinese scale. Logistic regression models and restricted cubic splines with covariate adjustment were performed to explore the association between pulmonary function and MCI risk.

Results

The prevalence of MCI increased with decreasing pulmonary function, from the lowest quartile to the highest quartile of pulmonary function: 63.9, 50.5, 43.8, and 43.6%, respectively. After adjustment for confounding factors, participants in the first quartile had a significantly increased risk of MCI (ORs, 1.691, 95% CI, 1.267-2.258), with the highest quartile as the reference. In the subgroup analysis, a significant association of pulmonary function and MCI was found in females and those with low physical activity. Meanwhile, we observed an L-shaped relationship between pulmonary function and MCI (P _non-linear = 0.032).

Conclusions

Poor pulmonary function was associated with an increased risk of MCI among rural Chinese adults, and presented a non-linear relationship. These findings remind us of the need for early cognitive assessment in local populations with lower pulmonary function.

Association of Peak Expiratory Flow with Cognitive Function in the Chinese Middle-Aged and Elderly Population: A 7-Year Longitudinal Study

BACKGROUND

Previous studies have shown that impaired pulmonary function may be associated with cognitive decline, posing the question of whether peak expiratory flow (PEF) % pred could present a modifiable risk factor.

OBJECTIVE

To assess the association between PEF% pred and future cognitive function among Chinese participants aged 45 years and above.

METHODS

Data came from four waves fielded by the China Health and Retirement Longitudinal Study. Cognitive function was assessed by a global cognition score. Multivariate linear regression models and generalized estimating equation (GEE) were used to investigate associations between PEF% pred and later cognitive function.

RESULTS

A total of 2,950 participants were eligible for the final data analysis. After adjustment for baseline cognition and potential confounders, the association remained statistically significant (β = 0.0057, p = 0.027). Domains with increases were focused on episodic memory (β= 0.0028, p = 0.048) and figure drawing (β= 0.0040, p = 0.028). But these associations were not found in women (β= 0.0027, p = 0.379). However, GEE suggested that the rates of decline in global cognition decreased by 0.0096 (p < 0.001) units per year as baseline PEF% pred increased by 1% in middle-aged and elderly individuals, regardless of sex. And higher baseline PEF% pred correlated with declined rates of decrease of in episodic memory, figure drawing, and Telephone Interview of Cognitive Status (TICS).

CONCLUSION

Higher baseline PEF% pred was significantly associated with slower cognitive decline in global cognition, episodic memory, figure drawing, and TICS in middle aged and elderly Chinese adults.

Association of a wide range of chronic diseases and apolipoprotein E4 genotype with subsequent risk of dementia in community-dwelling adults: A retrospective cohort study

Background

Identifying independent and interactive associations of a wide range of diseases and multimorbidity and apolipoprotein E4 (APOE4) with dementia may help promote cognitive health. The main aim of the present study was to investigate associations of such diseases and their multimorbidity with incident dementia.

Methods

In this retrospective cohort study, we included 471,485 individuals of European ancestry from the UK Biobank, aged 38-73 years at baseline (2006-10). Dementia was identified using inpatient records and death registers. The follow-up period was between March 16, 2006, and Jan 31, 2021.

Findings

During a median follow-up of 11·9 years, 6189 cases of incident all-cause dementia (503 young-onset cases, 5686 late-onset cases) were documented. In multivariable-adjusted analysis, 33 out of 63 major diseases were associated with an increased risk of dementia. The hazard ratio (HR [95% CI]) ranged from 1·12 (1·06-1·19) for obesity to 14·22 (12·33-16·18) for Parkinson's disease. In addition to conventional diseases, respiratory disorders, musculoskeletal disorders, digestive disorders, painful conditions, and chronic kidney disease were associated with increased dementia risk. A larger HR for dementia was observed for a larger number of diseases (3·97 [3·51-4·48] for ≥6 diseases versus no disease). These individual diseases and multimorbidity were more predictive of young-onset dementia than of late-onset dementia. Dementia risk score incorporating multimorbidity, age, and APOE4 status had strong prediction performance (area under the curve [95% CI]: 82·2% [81·7-82·7%]). APOE4 was more predictive of late-onset dementia (HR [95% CI]: 2·90 [2·75-3·06]) than of young-onset dementia (1·26 [1·03-1·54]). Associations of painful conditions, depression, obesity, diabetes, stroke, Parkinson's disease, high cholesterol, and their multimorbidity with incident dementia were stronger among non-APOE4 carriers.

Interpretation

Besides conventional diseases, numerous diseases are associated with an increased risk of dementia. These individual diseases and multimorbidity are more predictive of young-onset dementia, whereas APOE4 is more predictive of late-onset dementia. Individual diseases and multimorbidity are stronger predictors of dementia in non-APOE4 carriers. Although multiple risk factors have been adjusted for in the analysis, potential confounding from unknown factors may have biased the associations.

Funding

The Fundamental Research Funds of the State Key Laboratory of Ophthalmology, Project of Investigation on Health Status of Employees in Financial Industry in Guangzhou, China (Z012014075), Science and Technology Program of Guangzhou, China (202,002,020,049).

The association between pulmonary function and depression in middle-aged and elderly people in China: The role of cognitive ability and sleep time

BACKGROUND

Depression is a common mental disorder in middle-aged and elderly people, which seriously affects their physical health and life quality.So far, whether pulmonary function is a factor in depression has not been tested.The purpose of this study was to test whether pulmonary function was independently associated with depression and to assess the effects of cognitive ability and sleep time on this association.

METHODS

In this analysis, 5,235 participants from the Chinese Longitudinal Study of Health and Retirement were included. Participants were registered in 2015 and followed up in 2018. The relationship between pulmonary function and depression was estimated by binary logistic regression model. The mediated role of cognitive ability was examined by intermediary analysis, and the interaction between pulmonary function and sleep time on depression was discussed.

RESULTS

After adjusting for confounding factors, it was found that higher baseline pulmonary function was the protective factor of depression (OR [95%CI]=0.524 [0.394-0.697] for the lowest quantile vs the highest quantile). Cognitive ability explained 14.55% of the association between pulmonary function and depression, pulmonary function and sleep time on the effects of depression have a combined interaction, RERI (95%CI) = 0.545 (0.053-1.038).

CONCLUSIONS

High baseline pulmonary function is independently associated with a lower risk of depression, which is partly mediated by cognitive ability. Pulmonary function and sleep time have synergy with the effects of depression. These findings show that pulmonary function, cognitive ability and sleep time are reliable predictors of depression.