Associations of the Glycaemic Control of Diabetes with Dementia and Physical Function in Rural-Dwelling Older Chinese Adults: A Population-Based Study

Abstract

Purpose

To examine the associations of impaired fasting glucose (IFG) and glycaemic control of diabetes with dementia, global cognitive function and physical function among rural-dwelling Chinese older adults.

Patients and Methods

This population-based cross-sectional study included 4583 participants (age ≥65 years, 57.3% women) living in Yanlou Town, Yanggu County, western Shandong Province, China. In 2018, data were collected through interviews, clinical examinations, neuropsychological tests, and laboratory tests. Diabetes status was defined by self-reported physician-diagnosed diabetes, current use of antidiabetic agents, and fasting blood glucose tests. Global cognitive function was assessed using the Mini-Mental State Examination. Dementia was diagnosed following DSM-IV criteria, and Alzheimer’s disease (AD) was diagnosed following the National Institute on Aging-Alzheimer’s Association criteria. Physical function was assessed by the Short Physical Performance Battery. Data were analysed using multiple logistic and general linear regression models.

Results

IFG was found in 267 participants, and diabetes was diagnosed in 658 participants (257 with well-controlled diabetes, 401 with poorly controlled diabetes). Dementia was diagnosed in 166 participants (116 with AD), and physical functional impairment was found in 1973 participants. The multi-adjusted odds ratio (OR) of dementia associated with poorly controlled diabetes (vs without IFG or diabetes) was 2.41 (95% CI 1.52–3.84), and the OR of AD associated with poorly controlled diabetes was 2.32 (1.34–4.04). In addition, the adjusted OR of physical functional impairment was 1.40 (1.06–1.85) for well-controlled diabetes and 1.69 (1.35–2.12) for poorly controlled diabetes. However, IFG was not associated with cognitive or physical function.

Conclusion

The glycaemic control status of diabetes patients was associated with cognitive impairment and physical functional impairment.

Keywords:

• impaired fasting glucose
• Alzheimer’s disease
• cognitive function
• physical functional impairment

Acknowledgments

We would like to thank the study participants of MIND-China and all staff in the MIND-China research group for their invaluable contributions.

Abbreviations

AD, Alzheimer’s disease; ADLs, activities of daily living; APOE, Apolipoprotein E; ATC, Anatomical Therapeutic Chemical; BMI, body mass index; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, 4th Edition; HDL-C, high-density lipoprotein cholesterol; IFG, impaired fasting glucose; LDL-C, low-density lipoprotein cholesterol; MIND-China, Multimodal Intervention to Delay Dementia and Disability in Rural China; MMSE, Mini-Mental State Examination; NIA-AA, National Institute on Aging-Alzheimer’s Association; NINDS-AIREN, the National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l’Enseignement en Neurosciences; SPPB, Short Physical Performance Battery; TC, total cholesterol; TG, triglycerides; VaD, vascular dementia.

Data Sharing Statement

Data supporting the findings from this study will be available from the corresponding authors upon approval by the data management committee of MIND-China.

Ethics Approval and Informed Consent

MIND-China was approved by the Ethics Committee of Shandong Provincial Hospital in Jinan, Shandong. Written informed consent was obtained from all participants, or in the case of severely cognitively impaired participants, from informants. MIND-China was registered in the Chinese Clinical Trial Registry (registration no.: ChiCTR1800017758).

Consent for Publication

All authors confirm that the work described has not been published before; that it is not under consideration for publication elsewhere; and that its publication has been approved by all co-authors.

Author Contributions

All authors contributed to data analysis, drafting or revising the article, gave final approval of the version to be published, agreed to the submitted journal, and agreed to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.