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

Abstract

This study aimed to examine whether pulmonary function and cognition are independently associated at multiple time points. We included 8264 participants (49.9% women) aged 50-94 years at baseline from the China Health and Retirement Longitudinal Study in our analysis. Participants were enrolled in 2011 and followed up in 2013 and 2015. Cognitive function was assessed through a face-to-face interview in each survey. Pulmonary function was assessed via peak expiratory flow. Pulmonary function and cognitive function decreased significantly with age in both genders. Individuals in quintile 5 of pulmonary function had a relative increase in immediate memory (β (95% CI): 0.19 (0.09, 0.30)) and delayed memory (0.16 (0.04, 0.28)) during follow-up compared with those in quintile 1. In the repeated-measures analysis, each standard deviation increment of pulmonary function was associated with a 0.44 (95% CI: 0.34, 0.53), 0.12 (0.09, 0.15), 0.12 (0.08, 0.16), 0.08 (0.06, 0.11), and 0.10 (0.07, 0.14) higher increase in global cognitive score, immediate memory, delayed memory, orientation and subtraction calculation, respectively. The inverse association between pulmonary function and cognitive decline during follow-up was more evident in women (P for interaction=0.0333), low educated individuals (P for interaction=0.0002), or never smokers (P for interaction=0.0412). In conclusion, higher baseline pulmonary function was independently associated with a lower rate of cognitive decline in older adults. The positive association between pulmonary function and cognition was stronger in women, lower educated individuals, or never smokers.

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

“…Although the underlying mechanisms are unclear, our study is supported by recent evidence that poor pulmonary function might accelerate cognitive decline. 10 , 11 Our study is consistent with a previous study demonstrating that digestive disorders (diverticulitis and dyspepsia) were associated with a higher risk of dementia. 13 Inflammation in those with digestive disorders might increase the risk of dementia.…”

“… 8 Little is known regarding the association between types of cancers and incident dementia. It is also of great importance to confirm the associations of emerging risk factors for dementia including musculoskeletal disorders, painful conditions, 9 respiratory disorders (such as chronic obstructive pulmonary disease [COPD]), 10 , 11 chronic kidney disease (CKD), 12 and digestive disorders 13 with dementia in large prospective cohort studies. A recent prospective study has identified several physical diseases including erysipelas, hypothyroidism, duodenal ulcer, gastritis, and duodenitis (in addition to conventional risk factors), that may increase the long-term risk of dementia.…”

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

“…A longitudinal study of older Chinese adults demonstrated that the positive association between pulmonary function and cognition was stronger in females ( 17 ). Similar to our results, participants with poor pulmonary function had higher odds of MCI in the female group and in the physically inactive group.…”

“…Data retrieved from the AGES-Reykjavik Study revealed that lower pulmonary function measured in midlife predicted poor memory, processing speed, executive function, MCI and dementia 23 years later ( 12 ). Accumulating epidemiological studies have also illustrated that the global cognitive decline and a greater risk of dementia have a significant relationship to indicators with pulmonary function expressed as forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF) ( 12 – 17 ). However, previous studies have either focused on the association of COPD with dementia or MCI, or have targeted community-dwelling participants with relatively higher education and socioeconomic backgrounds, whereas information about the relationship between pulmonary function and MCI in rural populations is scarce ( 14 – 17 ).…”

“…Accumulating epidemiological studies have also illustrated that the global cognitive decline and a greater risk of dementia have a significant relationship to indicators with pulmonary function expressed as forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF) ( 12 – 17 ). However, previous studies have either focused on the association of COPD with dementia or MCI, or have targeted community-dwelling participants with relatively higher education and socioeconomic backgrounds, whereas information about the relationship between pulmonary function and MCI in rural populations is scarce ( 14 – 17 ). Furthermore, most studies have used only single a measure of ventilatory capacity to evaluate the respiratory condition and have not considered the resistance encountered during breathing and the contribution of respiratory muscles.…”