The study aimed to investigate the relationship between mobile phone use and cognitive impairment using the data of the Prevention and Intervention on Neurodegenerative Disease for Elderly in China (PINDEC) survey. A total of 21,732 participants aged 60 years and above in China were recruited using a stratified, multi-stage cluster sampling method, providing information on demographics, lifestyle and health-related characteristics, mobile phone use, and cognitive impairment through face-to-face interviews by trained staff according to a standard protocol. All estimates of rates were weighted by sex, age, and living area (rural or urban) in the elderly Chinese population. The rate of mobile phone usage was 65.5% (14.3% for smartphone use). The prevalence of cognitive impairment in non-users of mobile phone, dumbphone users, and smartphone users were 17.8%, 5.0%, and 1.4%, respectively. The odds of having cognitive impairment in users of dumbphone and smartphone were lower than non-users after adjusting for demographics, lifestyle, and health-related factors (adjusted odds ratio (AOR), 0.39, 95% CI 0.35 to 0.45; p < 0.001; AOR, 0.16, 95% CI 0.11 to 0.25; p < 0.001, respectively). Smartphone use in Chinese elderly people was quite low. A strong correlation was found between mobile phone use and better cognitive function; yet longitudinal studies are warranted to explore the causal relationship. Future design of mobile phone-based interventions should consider the feasibility among those in need.

Objective: This study aims to estimate the prevalence of dementia and Alzheimer's disease (AD) and associated risk factors among the general Chinese population.Methods: We carried out a nationwide study including 24,117 participants aged 60 years and older in China using a multistage clustered sampling. Dementia and AD were diagnosed according to the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders and the criteria issued by the National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer's Disease and Related Disorders Association. Face-to-face interviews were administered by the trained interviewers to obtain information on demographics, lifestyle factors, and previous diseases.Results: The overall weighted prevalence of dementia was 4.22% (95%CI 2.27–6.17%) for people aged 60 years and older, was higher in women than in men and increased with age. Daily tea drinking and daily exercises were the protective factors for both dementia and AD. Engaging in social and intellectual activities was significantly associated with a lower risk of dementia and AD.Conclusions: A large number of population with dementia posed a significant challenge to China where the population is rapidly aging. The increase of public awareness, building more care facilities, and training dementia specialists and professional caregivers are all urgently needed and should be the future priorities of dementia care in China.

Cardiometabolic diseases (CMDs) increases the risk of cognitive decline, but the extent to which this can be offset by adherence to an active integrated lifestyle is unknown. This prospective study used the baseline and 2-year follow-up data of 2537 dementia-free elderly ≥60 from PINDEC Project. Lifestyle factors (including physical exercise, social interaction, leisure activities, sleep quality, smoking, and alcohol consumption) were collected and the integrated score was calculated. Participants were divided into three groups based on integrated score tertiles (inactive, ≤3 score; intermediate, 4 score; and active, ≥5). Logistic regression was used in data analysis. 35.2 % participants had 5-6 healthy components, while only 5.4 % had all 6 healthy lifestyles. The multiadjusted odds ratios (ORs, 95 % confidence interval) of early cognitive decline was 1.223 (0.799-1.871) and 1.832 (1.140-2.943) for participants with only one CMD and any two or more CMDs, respectively. An inverse dose-response relationship was found between lifestyle scores and early cognitive decline (P_trend = 0.017). In participants with active lifestyle, the OR for early cognitive decline comparing the CMDs status of any two or more CMDs vs. CMDs-free was 0.778 (95%CI: 0.302-2.007). Participants with inactive lifestyle and any two or more CMDs had a near 3.4-fold increased risk of early cognitive decline than those without CMDs who had intermediate to active lifestyle (OR = 3.435, 95%CI: 1.772-6.660). Our research lacks information about nutrition. A dose-response relationship exists between CMDs status and risk of early cognitive decline. However, adherence to an active integrated lifestyle may mitigate this risk.

What is already known about this topic? Dementia affects approximately 5.3% of the population aged over 60 years in China — an estimated more than 10 million elderly people. Many older adults living with dementia have not been formally diagnosed, and a previous study found a peak of 93.1% of dementia patients during 2007–2011 remained undetected. What is added by this report? The latest undetected dementia rate and differences between urban and rural areas were estimated in this study based on a large nationwide study carried out in China in 2015–2016. The overall proportion of undetected dementia was 85.8%, 75.0% in males, 90.4% in females, 77.5% in urban residents, and 93.5% in rural residents. What are the implications for public health practice? Efforts should be made to increase the awareness of dementia in the public, to improve the capacity of early recognition of dementia by primary care physicians in community settings, and also to improve the local diagnostic capability of dementia.