Malnutrition is positively associated with cognitive decline in centenarians and oldest-old adults: A cross-sectional study

BACKGROUND

Cognitive decline is a growing public health concern. However, presently, only a few large-scale studies are available on the prevalence of cognitive decline worldwide, and the relationship between nutrition and cognitive decline remains unclear and requires further investigation, especially among Chinese centenarians and oldest-old adults. This study aimed to assess the prevalence of cognitive decline among Chinese centenarians and oldest-old adults, its associated factors, and explore a possible connection with nutrition, to provide new directions for the prevention of cognitive decline in Chinese centenarians and oldest-old adults.

METHODS

Based on the China Hainan Centenarian Cohort Study (CHCCS), a household survey was conducted among all the centenarians and oldest-old adults residing in 16 cities and counties of Hainan province from June 2014 to June 2016. This study included 946 centenarians and oldest-old adults (412 and 534, respectively). Cognitive function was measured using the mini-mental state examination (MMSE).

FINDINGS

The total prevalence of cognitive decline was 76·6% (725 participants). Centenarians had a significantly higher prevalence of cognitive decline compared to oldest-old adults [359 centenarians (87·1%) vs. 366 oldest-old adults (68·5%)]. Centenarians and oldest-old adults with cognitive decline had significantly lower prognostic nutritional index (PNI) and mini nutrition assessment-short form (MNA-SF) than those without cognitive decline (P < 0·05). Multivariate logistic regression analyses showed that participants with higher PNI and MNA-SF were less likely to have cognitive decline. Multivariate linear regression analyses showed that PNI and MNA-SF were positively associated with MMSE (P < 0·05).

INTERPRETATION

Malnutrition was positively associated with cognitive decline among Chinese centenarians and oldest-old adults. It is therefore important for clinicians and community health workers to pay attention to malnutrition in these populations and provide supplemental nutrients to prevent cognitive decline.

FUNDING

This work was supported by grants from the National Natural Science Foundation of China (81900357, 81903392, 81941021, 81901252, 82001476, 81802804, 81801251), the Military Medical Science and Technology Youth Incubation Program (20QNPY110, 19QNP060), the Excellent Youth Incubation Program of Chinese People's Liberation Army General Hospital (2020-YQPY-007), the Military Medicine Youth Program of Chinese People's Liberation Army General Hospital (QNF19069, QNF19068), the National Key R&D Program of China (2018YFC2000400), the National S&D Resource Sharing Service Platform Project of China (YCZYPT[2018]07), the Innovation Platform for Academinicians of Hainan Province, the Hainan Major Scientific and Technological Cooperation Project (2016KJHZ0039), the China Postdoctoral Science Foundation funded project (2019M650359, 2020M682816, 2021T140298), the Medical Big Data R&D Project of Chinese People's Liberation Army General Hospital (MBD2018030), the National Geriatric Disease Clinical Medicine Research centre Project (NCRCG-PLAGH-2017-014), the Central Health Care Scientific Research Project (W2017BJ12), the Hainan Medical and Health Research Project (16A200057), the Sanya Medical and Health Science and Technology Innovation Project (2016YW21, 2017YW22, 2018YW11), and the Clinical Scientific Research Supporting Fund of Chinese People's Liberation Army General Hospital (2017FC-CXYY-3009).

Successful aging and subjective well-being among oldest-old adults

PURPOSE OF THE STUDY

This research integrates successful aging and developmental adaptation models to empirically define the direct and indirect effects of 2 distal (i.e., education and past life experiences) and 5 proximal influences (i.e., physical functioning, cognitive functioning, physical health impairment, social resources, and perceived economic status) on subjective well-being. The proximal influences involved predictors outlined in most extant models of successful aging (e.g., Rowe & Kahn, 1998 [Rowe, J. W., & Kahn, R. L. (1998). Successful aging. New York: Pantheon Books.]). Our model extends such models by including distal impact as well as interactions between distal and proximal impacts.

DESIGN AND METHODS

Data were obtained from 234 centenarians and 72 octogenarians in the Georgia Centenarian Study. Structural equation modeling was conducted with Mplus 6.1.

RESULTS

Results showed significant direct effects of physical health impairment and social resources on positive aspects of subjective well-being among oldest-old adults. We also found significant indirect effects of cognitive functioning and education on positive affect among oldest-old adults. Social resources mediated the relationship between cognitive functioning and positive affect; and cognitive functioning and social resources mediated the relationship between education and positive affect. In addition, physical health impairment mediated the relationship between cognitive functioning and positive affect; and cognitive functioning and physical health impairment mediated the relationship between education and positive affect.

IMPLICATIONS

Integrating 2 different models (i.e., successful aging and developmental adaptation) provided a comprehensive view of adaptation from a developmental perspective.