Table 2.

Study descriptions and assessments

Study	Study Type	Sample	Cognitive Assessments Used	Cognitive Domains Assessed	Dementia Types Addressed
Catchlove et al (15)	Systematic review	10 studies with participants ages 30+, having a variety of comorbidities—2 examined subjects with diabetes mellitus	VF, TMT-A & B, WCST, CVLT, ROCF, IADL scale, MMSE	Executive function Learning and memory Perceptual-motor function *Global cognition	Alzheimer’s dementia, diabetes-related, other (moyamoya disease-related, multiple sclerosis-related)
Dai et al (14)	Longitudinal cohort study	72 adults ages 50–85 both with and without type 2 diabetes mellitus	VF, TMT-A & B, CDT, modified HVLT, DSF, DSB	Attention Executive function Learning and memory	Diabetes-related
Degen et al (17)	Nested case-control, from the ILSE longitudinal study	295 patients with mild cognitive impairment or Alzheimer’s dementia born between 1930 and 1932	Attentiveness endurance test (D2), DSST, Mosaic Test, WAIS (Finding Similarities), VF, Word List†	Attention Executive function Language Learning and memory	Alzheimer’s dementia, diabetes-related
Fukasawa et al (7)	Longitudinal cohort study	29 patients with Alzheimer’s dementia, and 18 patients with type 2 diabetes mellitus	Clinical diagnosis was used to determine diabetes and Alzheimer’s status	-	Alzheimer’s dementia, diabetes-related
Lee et al (68)	Cross-sectional, from wave 5 of the Atherosclerosis Risk in Communities (ARIC) study	2001 diabetic participants with a mean age of 76 years	DSST, DSB, TMT-A & B, VF (word fluency and phenomic fluency), BNT, CERAD I (episodic memory test), CERAD II (animal naming test), WAIS (logical memory tests parts 1 and 2, delayed word recall)	Attention Executive function Language Learning and memory	Diabetes-related
Luchsinger et al (69)	Cohort study, from the Diabetes Prevention Program (DPP) study	2280 participants aged 63.1 +/− 10.7 with type 2 diabetes mellitus years	DSST, VF (animal fluency and letter fluency), SEVLT	Executive function Language Learning and memory	Diabetes-related
Murray et al (24)	Observational extension of randomized trial: the ACCORD study	684 patients with intensive glycemia, and 644 patients with standard glycemia—all with a mean diabetes duration of 10 years, and mean age of 62	DSST, RAVLT, modified Stroop Color-Word Test, MMSE	Learning and memory Perceptual-motor function *Global cognition	Diabetes-related
Palta et al (19)	Nested case-control, from the Ginko Evaluation of Memory Study	3069 participants aged 72–96 years	WAIS-R(DSF and DSB), TMT-A & B, Stroop Color-Word Test, BNT, WAIS-R (block design), ROCF, CVLT	Attention Executive function Language Learning and memory Perceptual-motor function	Diabetes-related
Rajan et al (20)	Cohort study, from the Chicago Health and Aging Project (CHAP)	7740 adults aged 65+, with mean age 72.3 years	DSST, immediate and delayed recall of the East Boston Story, MMSE	Executive function Learning and memory *Global cognition	Diabetes-related
Sadanand et al (18)	Meta-analysis	Ages 50+	DSF, DSB, DSST, TMT-B, Stroop Color-Word Test, WCST, Brixton test, RAVLT, CVLT, WAIS, CERAD I and II, East Boston Memory test, Guild Paragraph test, VF	Attention Executive function Language Learning and memory	Diabetes-related
Wennberg et al (21,70)	Longitudinal cohort study, from the National Health and Aging Trends Study (NHATS)	7605 Medicare beneficiaries ages 65+ with diabetes mellitus and/or dementia diagnosis	CDT, CERAD I (episodic memory test)	Executive function Learning and memory	Diabetes-related, Alzheimer’s dementia, other‡

Abbreviations: AVLT/RAVLT, Rey’s Auditory Verbal Learning Test; BNT, Boston Naming Test; CDT, Clock Drawing Test; CERAD, Consortium to Establish a Registry for Alzheimer’s Disease; CVLT, California Verbal Learning Test; D2, Attentiveness Endurance Test; DSB, Digit Span Backwards Test; DSF, Digit Span Forward Test; DSST, Digit Symbol Substitution Test; HVLT, Hopkins Verbal Learning Test; IADL, Instrumental Activities of Daily Living; MMSE, Mini-Mental Status Exam; ROCF, Rey-Osterreith Complex Figure Test; SEVLT, Spanish English Verbal Learning Test; TMT-A & B, Trail Making Test A and B; WCST, Wisconsin Card Sorting Test; VF, Verbal Fluency Test; WAIS, Weschler Memory Test.

^*Global cognition assessed specifically by the MMSE.

^†These tests were taken from the German version of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders.

^‡Diagnosis of dementia was not specified between subtypes, although participants with diabetes were cognitively assessed.