Association of cognitive impairment with sleep quality, depression and cardiometabolic risk factors in individuals with type 2 diabetes mellitus: A cross sectional study
Introduction
The prevalence of type 2 diabetes mellitus (T2DM) is increasing globally and in India.1,2 A similar trend and increase in burden has been observed for dementia.3 In 2015, there were over 46 million people living with dementia worldwide, and 58% of these were living in lower and middle income countries (LMIC). This number is projected to double by 2030 and triple by 2050.4 Considering these trends, it is expected that increasing number of patients with concurrent diabetes and cognitive dysfunction will be seen in the near future. However, it seems that this association is not by chance alone. Epidemiological studies have revealed that the risk of incident mild cognitive impairment (up to 60%) and dementia (50–100%) is higher in people with T2DM than in people without diabetes.5 In addition, people with diabetes have cognitive decrements (0.2–0.5 SD, relative to people without diabetes) affecting their memory, executive functions and processing speed. These cognitive decrements start in pre-diabetes stage and evolve slowly over years at a rate which is nearly 50% faster than the normal cognitive ageing.6 This cognitive impairment may have important implications in diabetes self-management and social/occupational functioning.
Most research on diabetes related cognitive dysfunction has focussed on people above 65 years belonging to high-income countries. Less is known about the cognitive status of people with T2DM in South Asian region, where T2DM and metabolic syndrome are detected at least a decade earlier. A higher cardiovascular burden and lower education status add to the detrimental milieu. This paucity of data is striking, given the fact that 20% of the people with diabetes live in South Asia. Thus, it is crucial to assess the burden of cognitive impairment and its risk associations in this population. The data can have important implications for designing collaborative intervention studies, and understanding the vulnerable subgroups for appropriate management and prevention.
The current study reports the burden of cognitive impairment in individuals with Asian Indian T2DM age 30–70 years, and a comprehensive evaluation of associated bio-psychosocial risk factors in this ethnic group.
Section snippets
Settings and study design
This is a cross-sectional analysis of the baseline data on cognitive and psychological parameters (2017–2019), from the two-arm parallel lifestyle intervention randomized controlled trial conducted at two centers (New Delhi and Chennai), in India. Participants were identified and recruited from the out-patient department of All India Institute of Medical Sciences, New Delhi (tertiary care public hospital) and Madras Diabetes Research Foundation, Chennai (tertiary care private hospital). The
Baseline characteristics
The study enrolled 250 individuals with T2DM at a mean (± SD) age of 53.6 ± 9.1 years, median (IQR) diabetes duration of 8 (4-12) years and a mean (±SD) HbA1c of 55.1 ± 6.8 mmol/mol (7.2 ± 0.6%) (Table 1, Table 2). There were 50% women, 45.6% of the total participants had education <15 years (less than graduation), and 52.4% were unemployed (Table 1). Diabetes related vascular complications (both macrovascular and microvascular) were present in 28.4% of participants. There were 50.4% participants who
Discussion
The present study found a high burden of cognitive impairment (22.8%), depression (30.4%) and poor sleep quality (23.6%) in a cohort including middle-age individuals with T2DM, enrolled from North (New Delhi) and South (Chennai) India. The burden of cognitive impairment was found to be significantly higher in those with diabetes related vascular complications, depression, lower education, and hypertension. Individuals with global cognitive impairment (abnormal MoCA) also performed poorly on
Conclusion
To conclude, we report a significant burden of cognitive impairment in patients with diabetes including middle-age individuals. The presence of diabetes related vascular complications, hypertension, depression and lower education are important risk factors.
Data availability
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
Funding
This research was funded by the Indian Council for Medical Research, India to Yashdeep Gupta as Principal investigator with grant sanction No. 55/3/1/Yoga-Diab./17-NCD-III.
CRediT authorship contribution statement
Anu Gupta and YG conceptualised this manuscript and prepared the initial draft. MK did the statistical analysis. All authors helped in execution of study, collection or interpretation of data, critical review of manuscript and final approval of the manuscript. YG is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Acknowledgements
The authors are grateful to the study participants for generously donating their time and information. The authors would like to thank Yatender Singh, Ankit Rajput, Balram, and Arun Kumar for assistance in conducting the study.
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Declaration of competing interest: The authors declare that there is no duality of interest associated with this manuscript.