Cognitive function in diabetic persons with peripheral neuropathy: a systematic review and meta-analysis

Area of Science:

• Neuroscience
• Endocrinology
• Public Health

Background:

• Diabetes mellitus, both type 1 (T1DM) and type 2 (T2DM), is a global health concern.
• Peripheral diabetic neuropathy (DPN) is a common complication affecting a significant portion of diabetic individuals.
• Cognitive function deficits are increasingly recognized as a comorbidity in diabetes, impacting quality of life.

Purpose of the Study:

• To systematically review and synthesize existing research on cognitive function in individuals with T1DM or T2DM and DPN.
• To enhance understanding of the relationship between DPN and cognitive impairments in diabetic populations.
• To identify specific cognitive domains affected by DPN in both T1DM and T2DM.

Main Methods:

• A comprehensive systematic review and meta-analysis of studies published until November 2021.
• Searches were conducted across major scientific databases: PubMed, Scopus, PsycInfo, and Web of Science.
• Study registration with PROSPERO (CRD42021229163) ensured methodological transparency.

Main Results:

• 19 studies, selected from 832 initial articles, confirmed DPN's association with global cognitive impairment in T1DM and T2DM.
• Individuals with T2DM and DPN exhibited significantly lower mean cognitive performance compared to those without DPN (-1.0448; 95% CI: -1.93% to -0.16%).
• Impairments were observed in specific cognitive domains, including memory, attention, and psychomotor speed, with depression also linked to cognitive decline.

Conclusions:

• The findings support the presence of both global and domain-specific cognitive impairment in diabetic individuals with DPN.
• Significant variability in assessment instruments and methodologies was noted across the reviewed studies.
• Further research with standardized methods is warranted to fully elucidate the cognitive impact of DPN in diabetes.