Gender differences in the correlation between body mass index and cognitive impairment among the community-dwelling oldest-old in China: a cross-sectional study

Vitality at home: a phenomenological study of tele-exercise in women aged 80 and older

BACKGROUND

Since the onset of coronavirus 2019, there has been an upsurge of tele-exercise delivery. Previous studies showed old adults find tele-exercise feasible and acceptable. However, there is limited understanding of the oldest-old's experiences.

METHOD

This study used the interpretative phenomenological approach. Two semi-structured interviews and home visits were conducted with six oldest-old women, aged between 81 and 91 years, who participated in tele-exercise classes.

RESULTS

Four superordinate themes were identified: ambivalent perception of safety, ease in regular participation, reminded and guided to move the aged body, and technological adaptation.

CONCLUSION

Our findings indicate that tele-exercise has the potential to assist the oldest-old living in the community in maintaining an adequate activity levels at home, which they perceive as the safest place. Emerging themes provide insights into their lived experiences, enabling service providers to enhance tele-exercise services for this group in the tele-health era.

Prevalence of cognitive impairment and associated factors in older people

BACKGROUND

Older people are the fastest-growing age group, with the highest risk of cognitive impairment. This study assessed the prevalence and associated factors with cognitive impairment in community-dwelling older people.

METHODS

Older people were interviewed and accomplished through sociodemographic and health questionnaires. The quantitative variables were described by mean and standard deviation or median and interquartile range. The significance level adopted was 5 % (p < 0.05). The association between the quantitative variables was evaluated using the Pearson or Spearman correlation coefficients.

RESULTS

The research population comprised 165 long-lived adults aged ≥80. The youngest one was 80, and the oldest one was 94 years old. The participants were 84.8 ± 3.6 years old, female (63 %) with a mean of education of 2.9 ± 1.8 years. A poor performance in the Mini-Mental State Examination (MMSE) was found in 58 (35.2 %) individuals when adjusted for educational level. After adjustment for confounding factors, body mass index (BMI) (p = 0.09), total older adults' income (up to 1 minimum wage [mw], p = 0.023; over 1 to 2 mw, p = 0.023), functional disability (Moderate dependence 75 %, p = 0.038; Moderate dependence 50 %, p = 0.081; Moderate dependence 25 %, p = 0.054), and the anxiety scale (p = 0.032), remained associated with cognitive impairment.

CONCLUSIONS

This study showed that BMI, total older adults' income, functional disability, and anxiety are related to cognitive impairment in long-lived adults. This study has some limitations, such as the fact that it is a cross-sectional study, the reduced number of individuals, and the fact that there were no comparisons among different ages and populations.

Sex difference in the association between BMI and cognitive impairment in Chinese older adults

BACKGROUND

The association between body mass index (BMI) and cognitive impairment (CI) has been the subject of extensive research, yet the precise dose-response effects remain undefined.

METHODS

Older adults were selected from the 2011/2012 survey at baseline and the new recruits from the 2014 and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Multiple logistic regression models were used to evaluate the association between BMI categories and CI, and Restricted Cubic Spline (RCS) was used to explore the nonlinear relationship between BMI and CI.

RESULTS

The study included 29,380 older adults aged from 65 to 117 years, with an average age of 82 years. Of these, 13,465 were men, and 5359 exhibited cognitive impairment. The logistic model indicated that in female participants, being underweight was positively correlated with CI (OR:1.32; 95%CI 1.20-1.46), whereas being overweight was inversely correlated with CI (OR:0.86; 95%CI 0.75-0.99), and we didn't find any association between BMI category and CI in male participants. RCS modeling revealed a U-shaped relationship between BMI and CI. When stratified by sex, men exhibited a similar trend, with the lowest risk at a BMI of 22.774 kg/ m2, while women had the lowest risk of CI at a BMI of 24.817 kg/ m2.

LIMITATION

This was a cross-sectional study, it cannot provide information on causal relationships.

CONCLUSION

A U-shaped relationship was observed between BMI and CI in older adults, more pronounced in the male population, suggesting that male older adults may need to manage their BMI more rigorously.

Association between body mass index and cognitive impairment in Chinese older adults

Background

The association between body mass index (BMI) and the risk of cognitive impairment remains uncertain. Relatively few studies have analyzed the dose-response relationship between BMI and cognitive impairment. This article utilized nationally representative longitudinal data to assess the association between BMI and cognitive impairment in Chinese older adults.

Objective

The present study aimed to analyze the association between BMI and cognitive impairment in Chinese older people, including an investigation of gender differences and the dose-response relationship.

Methods

Data were obtained from the China Health and Retirement Longitudinal Study database in 2015 and 2018. The present study used logistic regression to analyze the relationship between baseline BMI and cognitive impairment, and adopted a restricted cubic spline model to plot dose-response curves for baseline BMI and prevalence of risk of cognitive impairment.

Results

The mean BMI of the survey population was 23.48 ± 3.66 kg/m2, and the detection rate of cognitive impairment was 34.2%. Compared to the normal weight group (18.5 ≤ BMI < 23.9 kg/m2), the odds ratio (OR) for cognitive impairment was 1.473 (95% CI: 1.189-1.823) in the underweight group (BMI < 18.5 kg/m2), whereas the corresponding OR was 0.874 (95% CI: 0.776-0.985) for the overweight or obese group (BMI ≥ 24.0 kg/m2) after adjusting for confounders. Gender subgroup analysis showed that overweight or obese older women were less likely to develop cognitive impairment (OR = 0.843; 95% CI: 0.720-0.987). The results of the restricted cubic spline analysis revealed a curvilinear L-shaped relationship between BMI and the risk of cognitive impairment (P non-linearity <0.05). In particular, the risk of cognitive impairment was higher at a lower baseline BMI. In contrast, BMI in the range of 23.2-27.8 kg/m2 was associated with a decreased risk of cognitive impairment.

Conclusion

BMI is a dose-dependent related factor for cognitive impairment in Chinese older adults. Being underweight is a risk factor for the development of cognitive impairment, while being overweight or obese is less likely to have cognitive impairment, particularly in female older people. Keeping BMI ranging from 23.2-27.8 kg/m2 in older adults can help maintain cognitive function.