Mediation analysis of plasma phosphorylated tau217 in the association between periodontitis and mild cognitive impairment

Dementia is associated with sleep disorders. However, the relationship between dementia and sleep arousal remains unclear. This study explored the associations among sleep parameters, arousal responses, and risk of mild cognitive impairment (MCI). Participants with the chief complaints of memory problems and sleep disorders, from the sleep center database of Taipei Medical University Shuang-Ho Hospital, were screened, and the parameters related to the Cognitive Abilities Screening Instrument, Clinical Dementia Rating, and polysomnography were determined. All examinations were conducted within 6 months and without a particular order. The participants were divided into those without cognitive impairment (Clinical Dementia Rating = 0) and those with MCI (Clinical Dementia Rating = 0.5). Mean comparison, linear regression models, and logistic regression models were employed to investigate the associations among obtained variables. This study included 31 participants without MCI and 37 with MCI (17 with amnestic MCI, 20 with multidomain MCI). Patients with MCI had significantly higher mean values of the spontaneous arousal index and spontaneous arousal index in the non-rapid eye movement stage than those without MCI. An increased risk of MCI was significantly associated with increased spontaneous arousal index and spontaneous arousal index in the non-rapid eye movement stage with various adjustments. Significant associations between the Cognitive Abilities Screening Instrument scores and the oximetry parameters and sleep disorder indexes were observed. Repetitive respiratory events with hypoxia were associated with cognitive dysfunction. Spontaneous arousal, especially in non-rapid eye movement sleep, was related to the risk of MCI. However, additional longitudinal studies are required to confirm their causality. Tsai C-Y, Hsu W-H, Lin Y-T, etal. Associations among sleep-disordered breathing, arousal response, and risk of mild cognitive impairment in a northern Taiwan population. J Clin Sleep Med. 2022;18(4): 1003-1012.

BackgroundSubjective cognitive decline (SCD) is a state in which individuals complain of cognitive impairment; however, they perform normally on standard neuropsychological tests. SCD is considered a diagnostic entity of risk for mild cognitive impairment (MCI) and dementia. SCD and MCI correspond to stages 2 and 3, respectively, in the clinical staging of the continuum of the Alzheimer's disease (AD). Portability of APOEε4 allele increases AD's risk, and its interaction with SCD might raise the cognitive impairment's risk. Herein, we aimed to explore the relationship between SCD, MCI and APOEε4 status in Mexican‐mestizo older adults.Method84 Mexican‐mestizo older adults (86.9% females) were included after consent was obtained (protocol INNN_139/23). Three comparable groups by age (69.37±6.51 y.o.) and years of schooling (13.46±2.92) were formed, n = 28/group, as follows: participants with normal cognition (NC), SCD and MCI. The MoCA and the Cognitive Complaint Questionnaire (CCQ) cut point scores at enrollment were used to classify the groups. APOE genotyping was assessed by allelic discrimination and SPSS was used for statistical analysis.ResultSignificant differences were observed in the cognitive performance between the NC and MCI groups (27.36±1.47 vs. 22.21± 2.06, p <0.001). Regarding the cognitive complaint, NC group showed the lowest score, followed by the DCS and MCI groups (11.71± 6.54, 28.18± 5.75 and 26.66± 9.89, p <0.001) (Table 1). The distribution of APOE genotype and allele frequencies of the studied sample was within Hardy–Weinberg equilibrium. Comparison of APOEε4 allele frequency was different between NC vs. SCD and MCI (p <0.005), while SCD and MCI groups behaved similarly (p >0.05). Being carrier of APOEε4 increased the risk of SCD (OR=5.17, CI95%=1.06‐25.13, p = 0.04) and MCI (OR=6.60, CI95%=1.39‐31.34, p = 0.02), compared to the NC group (Figure 1).ConclusionAn association between SCD, MCI and APOEε4 was identified in our sample of mestizo‐Mexican older adults; of note, no differences were found for APOEε4 allele between the SCD and MCI groups. The risk of portability of APOEe4 was comparable in SCD and MCI, highlighting SCD as a clinical risk prediction entity in the AD continuum. The relevance of SCD should be further studied in the prevention of dementia by improving early detection.

PurposeDiabetic retinopathy (DR) can increase the risk of mild cognitive impairment (MCI), which has been confirmed by previous researches. With the frequent occurrence of MCI in patients with DR, the early detection of MCI has become a research hot-spot. The aim of this study was to investigate the relationship between neuron-specific enolase (NSE) and MCI in patients with DR.Patients and MethodsA total of 124 patients with DR, including 56 MCI patients and 68 normal cognition patients, were recruited in this cross-sectional study. The demographic and clinical data of patients were collected through questionnaires. Serum NSE was measured using electrochemiluminescence immunoassay. The Minimum Mental State Examination (MMSE) scale was used to evaluate the cognitive function of the participants.ResultsCompared with the normal cognition group, serum NSE levels and HbA1c levels in the MCI group were higher, while MMSE scores and educational level were lower (P<0.05). Serum NSE levels were significantly negatively correlated with MMSE total score, attention and calculation score, and language score (P<0.05). After adjusting for confounding factors, serum NSE still increased the MCI risk in DR patients (OR:1.606, 95CI%:1.264–2.041, P<0.001). The areas under the receiver operating characteristics (ROC) curves (AUC) of the crude model and the adjusted model were 0.75 and 0.73, respectively.ConclusionA high serum NSE level is an independent risk factor for MCI in DR patients. In addition, serum NSE is expected to be a potential biomarker in DR patients with MCI.

Background: It is unclear whether cerebral blood flow variability is a sign of impaired vascular function or an adaptation to chronic cerebral hypoperfusion in individuals with cognitive dysfunction. Elevated arterial stiffness increases transmission of pulsatile pressure to the brain, but the relationship between arterial stiffness, the magnitude of cerebral blood flow variability, and cognitive dysfunction is unknown. In this pilot study, we hypothesized that carotid artery stiffness would be higher in individuals with mild cognitive impairment (MCI) compared with individuals with normal cognition (NC), resulting in higher cerebral blood flow variability. Methods: In individuals with MCI (N=5) or NC (N=7), R-wave to common carotid artery (CCA) pulse wave velocity (PWV) was assessed as an index of arterial stiffness (via tonometry). CCA velocity (CCAv) and middle cerebral artery velocity (MCAv) were measured via transcranial Doppler ultrasound, with concurrent measurements of mean arterial pressure (MAP) via finger photoplethysmography. The amplitude of MAP, CCAv, and MCAv oscillations in the low frequency range (LF; 0.07-0.15 Hz) were assessed via fast Fourier transformation, and normalized to total power (0.04-0.4 Hz) for each participant to account for high inter-individual variability. Relationships between R-wave-carotid PWV and LF variability in CCAv and MCAv were assessed via correlational analyses. Results: There were no between-group differences for R-wave-carotid PWV (MCI: 0.91±0.16 m/s vs. NC: 0.87±0.07 m/s; P=0.70), mean CCAv (MCI: 31.8±8.8 cm/s vs. NC: 29.7±2.0 cm/s; P=0.54), mean MCAv (MCI: 50.9±6.5 cm/s vs. NC: 47.9±12.7 cm/s; P=0.63), or MAP (MCI: 102.1±10.2 mmHg vs. 104.7±13.8 mmHg; P=0.73). While there was also no difference between groups for nLF power of CCAv (MCI: 0.28±0.03 au vs. NC: 0.33±0.10 au; P=0.41), nLF power for MCAv was lower in the MCI group (MCI: 0.26±0.07 au vs. 0.43±0.12; P=0.02). Overall, there was a strong positive correlation between R-wave-carotid PWV and CCAv nLF power (R=0.81, P=0.005), but a weaker relationship for MCAv nLF power (R=0.56, P=0.09). While sub-group correlational analyses are limited based on the small sample sizes, relationships between R-wave-carotid PWV and CCAv nLF power were high for both MCI (R=0.98, P=0.02) and NC (R=0.79, P=0.06) groups, but were lower for MCAv nLF power (MCI: R=-0.12, P=0.88; NC: R=0.69, P=0.13). Conclusion: Contrary to our hypothesis, there were no differences in R-wave-carotid PWV between groups, and blood flow variability was either similar between groups (for CCAv), or lower in the MCI group (for MCAv). Overall, there was a strong positive relationship between R-wave-carotid PWV and blood flow variability in the CCA, which was also observed in sub-analysis of the MCI and NC groups. Future investigations with a larger sample size are needed to definitively determine the role of arterial stiffness on cerebral blood flow variability with cognitive dysfunction. R56AG068630, NIH National Institute for Aging (NIA), “Hemodynamic Mechanisms Linking Aortic Arch Stiffness with Brain Insult in Older Adults” This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Decision letter: Stage-dependent differential influence of metabolic and structural networks on memory across Alzheimer’s disease continuum

BackgroundSemantic noise (SN) is a linguistic measurement that quantifies how well the conversation focuses on topics they are discussing. We hypothesized that by engaging in high frequent conversation which aimed to enhance cognitive reserve, the SN observed in older people’s conversations with mild cognitive impairment (MCI) would resemble those with normal cognition (NC).MethodWe analyzed transcriptions from a behavioral intervention randomized controlled trial, I‐CONECT (NCT02871921), which involved semi‐structured conversations between facilitators and participants. In the project, the experimental group engaged in 30‐minute semi‐structured conversations (four times per week for 6 months) via video‐chats. Every video‐chat is oriented to a predefined topic which was provided in a standardized order (e.g., dancing is the 1st conversation topic in the 2nd week). Out of 186 subjects randomized into the trial, 64 participants were randomized into the experimental group. Among them, 52 participants (26 MCI and 26 normal based on NACC D1) with sufficient recording quality during the 2nd week of the intervention (baseline) and during the last week (i.e., 24th) before the month 6 (M6) post‐intervention assessments (post‐trial assessments at M6) were used in this analysis. We utilized an automatic speech recognition (ASR) system to transcribe these recordings and measured each transcription’s SN. We analyzed the statistical difference of MSN (mean SN) between participants with MCI and those with NC at baseline (2nd week) and M6 (24th week).ResultsUsing two‐tailed t‐test, we found that at the baseline, MSN in MCI group was significantly higher than NC group (MCI: 2.09(0.34), NC: 1.87(0.35), p‐value: 0.024). After six months of social interaction, MCI and NC group were not significantly different (MCI: 1.81(0.47), NC: 1.95(0.47), p‐value: 0.280). Moreover, in MCI group, baseline’s MSN was significantly higher than M6’ (p‐value: 0.017), while, in NC group, there was no significant difference between baseline and M6 (p‐value: 0.465).ConclusionsWe showed that, through six months of social interaction, MCI group’s MSN reduces from significantly higher than NC group at the baseline to not significantly different from NC group at M6. This indicates that the high dosage of interactive conversations reduces MSN in the MCI group.

Amyloid-β42 (Aβ42) regulates synaptic plasticity and memory formation at physiological levels in the brain, but in Alzheimer’s disease (AD), it can disrupt brain function and glucose metabolism. This disruption contributes to cognitive decline and neuropsychiatric symptoms, highlighting the need to better understand its complex effects. This study investigated the associations among cerebrospinal fluid (CSF) Aβ42 levels, cerebral glucose metabolism (assessed via FDG-PET), neuropsychiatric symptoms (evaluated using the NPI), and cognitive performance (measured by ADAS-Cog13 and MoCA) in individuals with AD, mild cognitive impairment (MCI), and cognitively normal (CN) participants. After adjusting for age, gender, education, and ApoE ɛ4 status, a significant positive relationship between CSF Aβ42 levels and cerebral glucose metabolism was observed in the MCI and AD groups, but not in the CN group. In the MCI group, higher cerebral glucose metabolism was associated with reductions in both neuropsychiatric and depressive symptoms, suggesting that higher glucose metabolism reflect higher activation state of investigated brain regions. In contrast, in the CN group, elevated CSF Aβ42 levels were directly linked to increased depressive symptoms, indicating that higher CSF Aβ42 may contribute to depression even in the absence of cognitive decline. Further analysis revealed that CSF Aβ42 levels were indirectly associated with reduced neuropsychiatric and depressive symptoms through enhanced cerebral glucose metabolism as mediator solely in the MCI group. Regarding cognitive performance, cerebral glucose metabolism showed a strong relationship with cognition in both the MCI and AD groups. Furthermore, higher CSF Aβ42 levels were positively associated with better cognitive performance in the MCI and AD groups, with cerebral glucose metabolism potentially mediating this relationship, while no effect was seen in the CN group. In short, CSF Aβ42 positively influenced cerebral glucose metabolism, which was linked to reduced neuropsychiatric and depressive symptoms as well as improved cognitive performance in MCI and AD groups.

BackgroundThe aim of this study was to investigate the genetic polymorphisms in the homocysteine (HCY) metabolic enzymes in the Xinjiang Uygur population who have mild cognitive impairment (MCI).Material/MethodsBased on the epidemiological investigation, 129 cases of diagnosed Uygur MCI patients and a matched control group with 131 cases were enrolled for analyzing the association between the polymorphisms in the HCY metabolism related genes (C677T, A1298C, and G1968A polymorphisms in MTHFR, as well as the A2756G polymorphism in MS) and MCI by using the SNaPshot method. We then determined the homocysteine level in patients.ResultsIn Xinjiang Uygur subjects, the A1298C polymorphisms in MTHFR and the A2756G polymorphisms in the MS gene in the MCI group were different from those in the control group. However, the C677T and G1968A polymorphisms in the MTHFR gene in MCI patients were not different from those in the control group. Multivariate logistic regression showed that, in addition to the well-known risk factors, such as low education level, high cholesterol level, high level of low-density lipoprotein, and high homocysteine levels, the A>G mutation in the MS gene at the rs1805087 locus was another independent risk factor for MCI in the Uyghur MCI population. The risk of MCI in G allele carriers was 2.265 times higher than that in matched control individuals (95% CI: 1.205~4.256, P<0.05).ConclusionsThe genetic polymorphism of HCY metabolizing enzymes is correlated to the occurrence of MCI in the Xinjiang Uygur population. The A2756G polymorphism in the MS gene could be an independent risk factor for MCI in the Xinjiang Uygur population.

BackgroundResearch has shown disrupted structural network measures related to cognitive decline and future cortical atrophy during the progression of Alzheimer’s disease (AD). However, evidence regarding the individual variability of gray matter network measures and the associations with concurrent cognitive decline and cortical atrophy related to AD is still sparse.ObjectiveTo investigate whether alterations in single-subject gray matter networks are related to concurrent cognitive decline and cortical gray matter atrophy during AD progression.MethodsWe analyzed structural MRI data from 185 cognitively normal (CN), 150 mild cognitive impairment (MCI), and 153 AD participants, and calculated the global network metrics of gray matter networks for each participant. We examined the alterations of single-subject gray matter networks in patients with MCI and AD, and investigated the associations of network metrics with concurrent cognitive decline and cortical gray matter atrophy.ResultsThe small-world properties including gamma, lambda, and sigma had lower values in the MCI and AD groups than the CN group. AD patients had reduced degree, clustering coefficient, and path length than the CN and MCI groups. We observed significant associations of cognitive ability with degree in the CN group, with gamma and sigma in the MCI group, and with degree, connectivity density, clustering coefficient, and path length in the AD group. There were significant correlation patterns between sigma values and cortical gray matter volume in the CN, MCI, and AD groups.ConclusionThese findings suggest the individual variability of gray matter network metrics may be valuable to track concurrent cognitive decline and cortical atrophy during AD progression. This may contribute to a better understanding of cognitive decline and brain morphological alterations related to AD.

The magnitude of type 2 diabetes mellitus (T2DM) is ever-increasing in India, and at present, ~77 million people live with diabetes. Studies have established that T2DM increases the risk of neurodegenerative disorders. This study aimed to determine the age-related prevalence of mild cognitive impairment (MCI) in T2DM patients in the Indian population and to identify link between cognitive dysfunction in T2DM patients and serum lipid composition through untargeted and targeted lipidomic studies. Using a cross-sectional study, we evaluated 1278 T2DM patients with Montreal cognitive assessment test (MoCA) and digit symbol substitution test (DSST) for cognitive functions. As per MoCA, the prevalences of MCI in T2DM patients in age groups below 40, 41-50, 51-60, 61-70, 71-80 and 81-90 years were 13.7, 20.5, 33.5, 43.7, 57.1 and 75% with DSST scores of 45.8, 41.7, 34.4, 30.5, 24.2 and 18.8% respectively. Binomial logistic regression analysis revealed serum HbA1c ≥ 7.51, duration of T2DM over 20 years, age above 41 years, and females were independent contributors for cognitive dysfunction in T2DM patients. Preliminary studies with untargeted lipidomics of the serum from 20 T2DM patients, including MCI and normal cognition (NC) group, identified a total of 646 lipids. Among the identified lipids, 33 lipids were significantly different between MCI and NC group, which comprised of triglycerides (TGs, 14), sphingolipids (SL, 11), and phosphatidylcholines (PC, 5). Importantly, 10 TGs and 3 PCs containing long-chain polyunsaturated fatty acids (PUFA) were lower, while 8 sphingolipids were increased in the MCI group. Since brain-derived sphingolipids are known to get enriched in the serum, we further quantified sphingolipids from the same 20 serum samples through targeted lipidomic analysis, which identified a total of 173 lipids. Quantitation revealed elevation of 3 species of ceramides, namely Cer (d18:1_24:1), Hex1Cer (d16:0_22:6), and Hex2Cer (d28:1) in the MCI group compared to the NC group of T2DM patients. Overall, this study demonstrated an age-related prevalence of MCI in T2DM patients and highlighted reduced levels of several species of PUFA containing TGs and PCs and increased levels of specific ceramides in T2DM patients exhibiting MCI. Large-scale lipidomic studies in future could help understand the cognitive dysfunction domain in T2DM patients, while studies with preclinical models are required to understand the functional significance of the identified lipids.

BackgroundLinguistic measures derived from spontaneous conversations are behavioral indicators shown to be associated with cognitive functions. In this study, we investigated a natural language processing measure, semantic noise (SN), to quantify conversational patterns and monitor intervention‐induced changes. We hypothesized that (1) conversational patterns differ between older adults with mild cognitive impairment (MCI) and those with normal cognition (NC), and (2) after a high dosage of conversational interactions, the conversational patterns of individuals with MCI would resemble those of individuals with NC.MethodWe analyzed transcriptions from semi‐structured conversations in the I‐CONECT project (ClinicalTrials.gov: NCT02871921). Participants engaged in 30‐minute semi‐structured conversations four times per week via online video chats for six months. Each video chat session followed a predefined topic based on the week and session index (e.g., dancing was the topic of the first conversation session in the second week). Fifty‐two participants (26 MCI and 26 NC) had at least one recorded video chat during the second week of the intervention (baseline for this study) and during the final week (i.e., 24th week) of the six‐month intervention. We measured semantic noise (SN) for each conversation session. The mean SN (MSN) from the second and 24th weeks was used to represent the baseline and six‐month (M6) values, respectively.ResultsAt baseline, the MCI group's MSN was significantly higher than the NC group's (MCI: 2.09 ± 0.34, NC: 1.87 ± 0.35; p = 0.024). After six months, no significant difference was observed between groups (MCI: 1.81 ± 0.47, NC: 1.95 ± 0.47; p = 0.280). In the MCI group, baseline MSN was significantly higher than M6 MSN (p = 0.009), but no significant change occurred in the NC group (p = 0.426).ConclusionsWe demonstrated a conversational pattern difference between the MCI and NC groups at baseline. After six months of conversational interaction, the MCI group's MSN decreased, shifting from being significantly higher than that of the NC group at baseline to no significant difference at M6. This suggests that following the intervention, the speech pattern of the MCI group resembled that of the NC group.

The aim of this study was to determine the effects of apolipoprotein E ε4 (APOE ε4) genotype and sex together on longitudinal change in adjusted hippocampal volume [hippocampal volume:intracranial volume ratio (HpVR)] across the Alzheimer's disease (AD) continuum. At baseline, we included 372 individuals with normal cognition (NC), 738 individuals with mild cognitive impairment (MCI) and 271 patients with mild AD from the Alzheimer's Disease Neuroimaging Initiative database. We examined the effects of the APOE ε4 by sex interaction on longitudinal change in HpVR within the overall sample and within each diagnostic group. Female gender was found to be associated with longitudinal reduction of HpVR in the NC and MCI groups, but not in the AD group. Similarly, APOE ε4 was associated with longitudinal reduction of HpVR in the NC and MCI groups, but not in the AD group. Further, female APOE ε4 carriers showed a greater longitudinal reduction of HpVR than their male counterparts in the NC group, but not in the MCI or AD group. However, due to the relatively short duration of follow-up visits in patients with AD, further studies are needed to replicate these findings. Female APOE ε4 carriers show a greater longitudinal reduction of HpVR than their male counterparts in cognitively normal older adults.

Objective Executive dysfunction after stroke greatly affects stroke prognosis, so clinicians need to urgently focus on screening for it. This study aims to offer valuable data for research on post-stroke executive dysfunction by evaluating the test-retest reliability of the Shape Trail Test (STT) and the influence of the practice effect on scores among stroke patients. Methods A total of 75 subacute stroke patients were included in the study. Based on the cutoff value for mild cognitive impairment(MCI) in the Chinese version of the Montreal Cognitive Assessment-Basic, the patients were divided into an MCI group and a cognitively normal (CN) group. The patients were asked to complete the Shape Trail Test (STT) on two different occasions within three days. The time taken to complete Part A and Part B were denoted as STT-A and STT-B respectively. The intraclass correlation coefficient(ICC), Pearson and Spearman correlation coefficients were used as metrics, and a paired t test was employed to evaluate the practice effect. Results (1) The actual number of patients who completed the research was 71. The STT showed great test-retest reliability in stroke patients (ICC, STTA: 0.927 VS STTB: 0.881; Spearman, STTA: 0.824 VS STTB: 0.713, n = 71). The test-retest reliability of STTA is higher than that of STTB (ICC, STTA = 0.927＞STTB = 0.881; Spearman, STTA = 0.824＞STTB = 0.713; n = 71). The reliability of the MCI group was higher than that of the CN group (ICC, STTA:MCI = 0.94＞CN = 0.71; STTB:MCI = 0.87＞CN = 0.64). (2) Subgroup analysis revealed distinct practice effects between the MCI and CN groups. The MCI group showed no practice effect, while the CN group had a partial one. In the CN group, practice did not significantly impact STT-A scores (p = 0.782), but did affect STT-B scores (p = 0.035). In contrast, in the MCI group, no significant practice effects on the STT were observed (p > 0.05). Conclusions STT’s test-retest reliability was moderate to high in stroke patients and varied by cognitive function. Subgroup analyses should precede assessments of STT’s test-retest reliability in stroke patients. Patients with cognitive dysfunction showed no significant practice effects. Given that this research is carried out specifically within the Chinese context, extreme care should be taken in extending the study’s findings to other populations. Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01322607

Mapping of the distribution of local susceptibility strength could be very important in understanding the mechanisms of progression in neurodegenerative diseases, due to depositions of iron and iron-containing plaques. The goal of this study is to map the voxelwise distribution of local cross-term b-value (b(c)) effect caused by interactions between the external and internal gradients, in subjects with Alzheimer's disease (AD), mild cognitive impairment (MCI), and cognitively normal (CN) elderly, using a diffusion tensor (DT) MRI. Two DT-MRI experiments were conducted with opposite polarities of the external diffusion-sensitizing gradients, and the authors modeled the 3 × 3 tensor matrix of b(c) maps and drove a rotationally independent mean b(c) (i.e., MB(c)) maps. To test whether AD has higher cross-term gradients than MCI and∕or CN, 15 AD patients, 18 MCI patients, and 16 CN controls were acquired from DT-MRI data, with six diffusion encoding directions, five b-values (0, 160, 360, 640, and 1000 s∕mm(2)), and positively and negatively alternating polarities of the external diffusion-sensitizing gradients. The b(c) and MB(c) maps were calculated and were spatially normalized into a study specific template for all subjects. The differences of MB(c) maps across the three subject groups were investigated with voxelwise one-way ANOVA tests for each b-value. The differences of MB(c) maps, among the four b-values, were also investigated with a voxelwise one-way within-subject ANOVA test for each group. The authors successfully mapped the local cross-term strength, using a DT-MRI data in the three groups. The MB(c) differences between the groups were increased with increasing b-values. Compared with the CN group and the MCI group, MB(c) values in the AD group were significantly increased. However, compared with the CN group, MB(c) values in the MCI group were not significantly different for all the b-values. In order to map the b-matrix cross-term effect, the authors developed a rotationally invariant index of MB(c), and the index was applied in AD, MCI, and CN subjects. In the AD group, compared with the MCI and CN groups, MB(c) values were increased. AD patients may have much more local intrinsic gradients in the brain than those MCI or CN subjects. MB(c) maps may be used to detect the intrinsically susceptible materials in the human brain, such as iron-containing plaques in the brain with AD.

Objective To study the association between blood glucose control and mild cognitive impairment (MCI) in patients with diabetes mellitus and small-artery occlusion (SAO). Methods A screening study of cognitive impairment was conducted in the 676 patients diagnosed with SAO who had been treated at Department of Neurology, Huanhu Hospital from January 2010 through June 2017. They were divided into a normal cognition group (n=629) and an MCI group (n=47) according to the screening results. They were also divided into 4 groups according to their history of diabetes and levels of hemoglobin A1c: normal blood glucose group (n=398), stringent goals group (n=59), general goals group (n=46) and goals-not-met group (n=173). The differences were compared in terms of Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment Scale (MoCA) scores between the normal blood glucose, stringent goals, general goals and goals-not-met groups. We also analyzed the general clinical data and risk factors between the normal cognition and MCI groups. Variables of confounders that were identified as significant were entered into logistic regression. Results There were significant differences in MMSE and MoCA scores between the 4 groups (P<0.05). Between the normal cognition and MCI groups, significant differences were found in proportion of smokers, blood glucose level and severity of stroke (P<0.05). Logistic regression analysis showed that compared with the normal blood glucose group the incidence of MCI was 2.707-fold higher in the stringent goals group (OR=2.707, 95% CI: 1.035~7.083, P=0.042), 2.963-fold higher in the general goals group (OR=2.963, 95% CI: 1.064~8.277, P=0.038) and 2.604-fold higher in the goals-not-met group (OR=2.604, 95% CI: 1.269~5.341, P=0.009). Conclusions MCI is more likely to occur in acute phase in patients with diabetes and SAO stroke. The patients can benefit from joint managements of diabetes, stroke and cognitive dysfunction in clinical practice. Key words: Stroke; Small-artery occlusion; Diabetes mellitus; Blood glucose control; Mild cognitive impairment