Year: 2017
Type: article
Study design: Observational Study
Abstract: Poor pulmonary function is associated with worse cognition and greater brain atrophy in midlife and increased risk of dementia-associated mortality. However, it is unclear if there is a longitudinal association between pulmonary function in midlife and dementia, and if so, whether the association is spurious due to mutual risk factors such as hypertension, vascular disease, and smoking. We evaluated 10,067 members of Kaiser Permanente Northern California ages 40–45 between 1964–1973 who remained members as of 1/1/96. Midlife pulmonary function was assessed by forced expiratory volume in one second (FEV1) during clinical exams between 1964–1973 and ranked into quintiles. Height, weight, race, education, and smoking (current, past, or never) were also collected between 1964–1973. Electronic health records from 1/1/1996–10/1/2015 were used to identify cases of dementia (ICD-9 codes 331.0, 290.4x, 290.0, 290.1x, 290.2x, 290.3, 294.2x, and 294.8), stroke, heart failure, and diabetes. Cox proportional hazard models (age as time scale) evaluated the association between the lowest quintile of midlife pulmonary function and dementia risk adjusted for sociodemographics and vascular risk factors across the lifecourse. Participants were censored at dementia diagnosis, death, gap in health plan membership, or end of study. The cohort was 55% female and 73% White. The lowest quintile of FEV1 values ranged between 0.2–2 liters and 30% were diagnosed with dementia over 20 years of follow-up. Compared to members in the highest quintile of FEV1, members in the lowest quintile of FEV1 were 20% more likely to develop dementia (adjusted Hazards Ratio (aHR)=1.20; 95% Confidence Interval:1.02–1.40) adjusting for height and sociodemographics. This relationship persisted after further adjustment for BMI and hypertension at midlife (aHR=1.18; 95% CI:1.01–1.38) but was slightly attenuated after controlling for midlife smoking (aHR=1.17; 95% CI:0.99–1.37). Members in the lowest quintile of FEV1 had almost 30% greater dementia risk (aHR=1.29; 95% CI:1.10–1.51) adjusting for height, sex, race, education, smoking, midlife risk factors (BMI, hypertension, smoking) and late life medical conditions (diabetes, heart failure, stroke). Low levels of midlife pulmonary function were associated with risk of dementia independent of hypertension and smoking. Further research is needed to identify the relevant pathogenic mechanisms.
Source: Alzheimer s & Dementia
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2765559488