Amyloid deposition and small vessel disease are associated with cognitive function in older adults with type 2 diabetes

Diabetes is associated with cognitive decline, but the underlying mechanisms are complex and their relationship with Alzheimer's Disease biomarkers is not fully understood. We assessed the association of small vessel disease (SVD) and amyloid burden with cognitive functioning in 47 non-demented older adults with type-2 diabetes from the Israel Diabetes and Cognitive Decline Study (mean age 78Y, 64% females). FLAIR-MRI, Vizamyl amyloid-PET, and T1W-MRI quantified white matter hyperintensities as a measure of SVD, amyloid burden, and gray matter (GM) volume, respectively. Mean hemoglobin A1c levels and duration of type-2 diabetes were used as measures of diabetic control. Cholesterol level and blood pressure were used as measures of cardiovascular risk. A broad neuropsychological battery assessed cognition. Linear regression models revealed that both higher SVD and amyloid burden were associated with lower cognitive functioning. Additional adjustments for type-2 diabetes-related characteristics, GM volume, and cardiovascular risk did not alter the results. The association of amyloid with cognition remained unchanged after further adjustment for SVD. Our findings suggest that SVD and amyloid pathology may independently contribute to lower cognitive functioning in non-demented older adults with type-2 diabetes, supporting a multimodal approach for diagnosing, preventing, and treating cognitive decline in this population.

The association between regional adiposity, cognitive function, and dementia-related brain changes: a systematic review

Background

Adiposity has been previously associated with cognitive impairment and Alzheimer's disease and related disorders (ADRD). Body mass index (BMI) is the most common measure of global adiposity, but inconsistent results were found since it is a global measurement. BMI does not represent regional fat distribution which differs between sexes, race, and age. Regional fat distribution may contribute differently to cognitive decline and Alzheimer's disease (AD)-related brain changes. Fat-specific targeted therapies could lead to personalized improvement of cognition. The goal of this systematic review is to explore whether regional fat depots, rather than central obesity, should be used to understand the mechanism underlying the association between adiposity and brain.

Methods

This systematic review included 33 studies in the English language, conducted in humans aged 18 years and over with assessment of regional adiposity, cognitive function, dementia, and brain measures. We included only studies that have assessed regional adiposity using imaging technics and excluded studies that were review articles, abstract only or letters to editor. Studies on children and adolescents, animal studies, and studies of patients with gastrointestinal diseases were excluded. PubMed, PsychInfo and web of science were used as electronic databases for literature search until November 2022.

Results

Based on the currently available literature, the findings suggest that different regional fat depots are likely associated with increased risk of cognitive impairment, brain changes and dementia, especially AD. However, different regional fat depots can have different cognitive outcomes and affect the brain differently. Visceral adipose tissue (VAT) was the most studied regional fat, along with liver fat through non-alcoholic fatty liver disease (NAFLD). Pancreatic fat was the least studied regional fat.

Conclusion

Regional adiposity, which is modifiable, may explain discrepancies in associations of global adiposity, brain, and cognition. Specific regional fat depots lead to abnormal secretion of adipose factors which in turn may penetrate the blood brain barrier leading to brain damage and to cognitive decline.

Stability in BMI over time is associated with a better cognitive trajectory in older adults

OBJECTIVE

Evidence on simultaneous changes in body mass index (BMI) and cognitive decline, which better reflect the natural course of both health phenomena, is limited.

METHODS

We capitalized on longitudinal data from 15,977 initially non-demented elderly from the Alzheimer's Disease Centers followed for 5 years on average. Changes in BMI were defined as (1) last minus first BMI, (2) mean of all follow-up BMIs minus first BMI, and (3) standard deviation of BMI change from baseline and all follow-up visits (representing variability).

RESULTS

Participants with significant changes in BMI (increase or decrease of ≥5%), or who had greater variability in BMI, had faster cognitive decline. This pattern was consistent irrespective of normal (BMI < 25; N = 5747), overweight (25 ≤ BMI < 30; N = 6302), or obese (BMI ≥ 30; N = 3928) BMI at baseline.

CONCLUSIONS

Stability in BMI predicts better cognitive trajectories suggesting clinical value in tracking BMI change, which is simple to measure, and may point to individuals whose cognition is declining.

Alzheimer’s Disease Polygenic Risk Score Is Not Associated With Cognitive Decline Among Older Adults With Type 2 Diabetes

Objectives

Multiple risk loci for late-onset Alzheimer’s disease (LOAD) have been identified. Type 2 diabetes (T2D) is a risk factor for cognitive decline, dementia and Alzheimer’s disease (AD). We investigated the association of polygenic risk score (PRS) for LOAD with overall cognitive functioning and longitudinal decline, among older adults with T2D.

Methods

The study included 1046 Jewish participants from the Israel Diabetes and Cognitive Decline (IDCD) study, aged ≥ 65 years, diagnosed with T2D, and cognitively normal at baseline. The PRS included variants from 26 LOAD associated loci (at genome-wide significance level), and was calculated with and without APOE. Outcome measures, assessed in 18 months intervals, were global cognition and the specific domains of episodic memory, attention/working memory, executive functions, and language/semantic categorization. Random coefficient models were used for analysis, adjusting for demographic variables, T2D-related characteristics, and cardiovascular factors. Additionally, in a subsample of 202 individuals, we analyzed the association of PRS with the volumes of total gray matter, frontal lobe, hippocampus, amygdala, and white matter hyperintensities. Last, the association of PRS with amyloid beta (Aβ) burden was examined in 44 participants who underwent an 18F-flutemetamol PET scan.

Results

The PRS was not significantly associated with overall functioning or decline in global cognition or any of the specific cognitive domains. Similarly, following correction for multiple testing, there was no association with Aβ burden and other brain imaging phenotypes.

Conclusion

Our results suggest that the cumulative effect of LOAD susceptibility loci is not associated with a greater rate of cognitive decline in older adults with T2D, and other pathways may underlie this link.

Long-term trajectories and current BMI are associated with poorer cognitive functioning in middle-aged adults at high Alzheimer's disease risk

INTRODUCTION

We examined relationships of body mass index (BMI) with cognition in middle-aged adults at Alzheimer's disease (AD) risk due to parental family history.

METHODS

Participants are offspring of AD patients from the Israel Registry of Alzheimer's Prevention (N = 271). Linear regressions assessed associations of BMI and cognition, and whether associations differed by maternal/paternal history. Analyses of covariance examined associations of long-term trajectories of BMI with cognition.

RESULTS

Higher BMI was associated with worse language (P = .045). Interactions of BMI with parental history were significant for episodic memory (P = .023), language (p = .027), working memory (P = .006), global cognition (P = .008); associations were stronger among participants with maternal history. Interactions of BMI trajectories with parental history were significant for episodic memory (P = .017), language (P = .013), working memory (P = .001), global cognition (P = .005), with stronger associations for maternal history.

DISCUSSION

Higher BMI and overweight/obese trajectories were associated with poorer cognition in adults with maternal history of AD, but not those with paternal history.

Abstract 2716: P-selectin axis plays a key role in microglia immunophenotype and glioblastoma progression

Glioblastoma (GB) is an aggressive type of brain cancer with high mortality rate. It is a highly angiogenic tumor exhibiting an extremely invasive nature. As such, its brain microenvironment plays a crucial role in its progression. Microglia are the brain resident immune cells which have been shown to facilitate GB cell invasion and immune suppression. The mechanism by which GB cells alter microglia behavior is yet to be fully understood. One proposed mechanism involves adhesion molecules such as the Selectins family of proteins which are expressed on the surface of endothelial and immune cells and are involved in immune modulation and cancer immunity. We have previously shown that P-Selectin (SELP) is expressed by GB cells. Here, we investigated the factional role of SELP in GB-microglia interactions. First, we found that microglia cells facilitate the expression and secretion of SELP by GB cells, and that GB cells facilitate the expression of P-Selectin ligand by microglia. We then showed that SELP mediates microglia-enhanced GB invasion and proliferation in 2D and 3D in vitro models and has a role in microglia activation state. These findings were validated in vivo, showing that inhibition or downregulation of SELP leads to reduced tumor growth, increased overall survival and improved immune response. Single-Cells RNA-seq analysis of the tumors revealed an increase in pro-inflammatory microglia signature, reduction in cancer cell tumorigenesis potential and improved T cell activation. Our results indicated that SELP has an important role in GB progression and microenvironment activation. This work can improve our understanding of tumor-associated microglia function and the mechanisms by which GB cells suppress the immune system and invade the brain tissue.

Citation Format: Eilam Yeini, Paula Ofek, Sabina Pozzi, Nitzan Albeck, Dikla Ben-Shushan, Galia Tiram, Sapir Golan, Ron Kleiner, Ron Sheinin, Shlomit Reich-Zeliger, Rachel Grossman, Zvi Ram, Henry Brem, Thomas Hyde, Prerna Magod, Dinorah Friedmann-Morvinski, Asaf Madi, Ronit Satchi-Fainaro. P-selectin axis plays a key role in microglia immunophenotype and glioblastoma progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2716.

The Israel Registry for Alzheimer's Prevention (IRAP) Study: Design and Baseline Characteristics

BACKGROUND

Family history of Alzheimer's disease (AD) is associated with increased dementia-risk.

OBJECTIVE

The Israel Registry for Alzheimer's Prevention (IRAP) is a prospective longitudinal study of asymptomatic middle-aged offspring of AD patients (family history positive; FH+) and controls (whose parents have aged without dementia; FH-) aimed to unravel the contribution of midlife factors to future cognitive decline and dementia. Here we present the study design, methods, and baseline characteristics.

METHODS

Participants are members of the Maccabi Health Services, 40-65 years of age, with exquisitely detailed laboratory, medical diagnoses and medication data available in the Maccabi electronic medical records since 1998. Data collected through IRAP include genetic, sociodemographic, cognitive, brain imaging, lifestyle, and health-related characteristics at baseline and every three years thereafter.

RESULTS

Currently IRAP has 483 participants [mean age 54.95 (SD = 6.68) and 64.8% (n = 313) women], 379 (78.5%) FH+, and 104 (21.5%) FH-. Compared to FH-, FH+ participants were younger (p = 0.011), more often males (p = 0.003) and with a higher prevalence of the APOE E4 allele carriers (32.9% FH+, 22% FH-; p = 0.040). Adjusting for age, sex, and education, FH+ performed worse than FH-in global cognition (p = 0.027) and episodic memory (p = 0.022).

CONCLUSION

Lower cognitive scores and higher rates of the APOE E4 allele carriers among the FH+ group suggest that FH ascertainment is good. The combination of long-term historical health-related data available through Maccabi with the multifactorial information collected through IRAP will potentially enable development of dementia-prevention strategies already in midlife, a critical period in terms of risk factor exposure and initiation of AD-neuropathology.

P-selectin axis plays a key role in microglia immunophenotype and glioblastoma progression

Glioblastoma (GB) is a highly invasive type of brain cancer exhibiting poor prognosis. As such, its microenvironment plays a crucial role in its progression. Among the brain stromal cells, the microglia were shown to facilitate GB invasion and immunosuppression. However, the reciprocal mechanisms by which GB cells alter microglia/macrophages behavior are not fully understood. We propose that these mechanisms involve adhesion molecules such as the Selectins family. These proteins are involved in immune modulation and cancer immunity. We show that P-selectin mediates microglia-enhanced GB proliferation and invasion by altering microglia/macrophages activation state. We demonstrate these findings by pharmacological and molecular inhibition of P-selectin which leads to reduced tumor growth and increased survival in GB mouse models. Our work sheds light on tumor-associated microglia/macrophage function and the mechanisms by which GB cells suppress the immune system and invade the brain, paving the way to exploit P-selectin as a target for GB therapy.

Exploring the role of perceived vs. observed behavioral outcomes in parental grief reaction following pediatric acquired brain injury

BACKGROUND

Pediatric acquired brain injury may result in a significant gap between the "pre" and "post-injury" child.

OBJECTIVE

We aimed to quantitatively explore the mechanism underlying parents' loss experience by examining the mediating role of behavioral outcomes (observed-problems and perceived-change) in the relationship between injury severity and grief.

METHOD

The study employed a cross-sectional retrospective design and comprised 40 parents of children (aged 3-18 years) with moderate-severe brain injury. Data for each parent included an adapted version of the Two-Track Bereavement Questionnaire and Socio-demographics; Data for each child included the child's Information Processing Speed Index; the Child Behavioral Checklist and Parental Perception of Behavioral Changes scale.

RESULTS

Slowed information processing speed was significantly associated with elevated ratings on both measures of behavioral outcomes and with intensified grief. Mediation analyses revealed that parental perceived behavioral change, significantly mediate the relationship between information processing speed and grief; the Child Behavioral Checklist total score also mediated the same relationship but only in 90% confidence interval.

CONCLUSIONS

Findings reveal the adverse impact of behavioral outcomes on grief and suggest parents' loss experience to be stemming primarily from their subjective perception over their "changed-child", rather than the observed problems. Implications for clinical practice are discussed.

Factors associated with parental grief reaction following pediatric acquired brain injury

The present study investigated factors associated with parental grief reaction (PGR) following pediatric acquired brain injury (ABI), and compared PGR to the one exhibited following child death. Fifty-seven parents of 51 children (aged 3-18) whose ABI occurred 1-14 years before participation, completed the multi-scale Two-Track Bereavement Questionnaire; a socio-demographic questionnaire; and a scale assessing perceived behavioural changes in the child. Results from regression analysis indicated that time since injury had no impact on parents' grief other than having an adverse impact on their overall coping and functioning; A higher amount of weekly caring hours predicted only a greater traumatic perception of the loss; Older children's ages but mostly greater parental-perceived behavioural changes, predicted greater PGR on most scales. PGR was compared with the pre-existing data of bereaved parents who completed the same grief questionnaire. Although grief response patterns and intensity were similar in both groups, significant differences were found on scales assessing the continuing bond with the child: relational active grief, close and positive relationship, and conflictual relationship. Our findings indicate that parental grief is multi-dimensional following pediatric ABI and illuminate the interplay between elements characterizing parents' nonfinite vs. finite loss experience.

Ureteric stent versus percutaneous nephrostomy for acute ureteral obstruction - clinical outcome and quality of life: a bi-center prospective study

BACKGROUND

To compare quality of life (QoL) indices between ureteral stent (DJS) and nephrostomy tube (PCN) inserted in the setting of acute ureteral obstruction.

METHODS

Prospective bi-centered study. Over the span of 2 years, 45 DJS and 30 PCN patients were recruited. Quality of life was assessed by 2 questionnaires, EuroQol EQ-5D and 'Tube symptoms' questionnaire, at 2 time points (at discharge after drainage and before definitive treatment).

RESULTS

Patients' demographics and pre-drainage data were similar. There were no clinically significant differences in patient's recovery between the groups, including post procedural pain, defeverence, returning to baseline renal function, and septic shock complications. More DJS patients presented to the emergency room with complaints related to their procedure compared to PCN patients. At first, DJS patients complained more of urinary discomfort while PCN patients had worse symptoms relating to mobility and personal hygiene, with both groups achieving similar overall QoL score. At second time point, PCN patients' symptoms ameliorated while symptoms in the DJS group remained similar, translating to higher overall QoL score in the PCN group.

CONCLUSIONS

The two techniques had a distinct and significantly different impact on quality of life. Over time, PCN patients' symptoms relieve and their QoL improve, while DJS patients' symptoms persist. Specific tube related symptoms, and their dynamics over time, should be a major determinant in choosing the appropriate drainage method, especially when definitive treatment is not imminent.

Characteristics and clinical significance of bacterial colonization of ureteral double-J stents in children

OBJECTIVE

To determine the frequency, type of pathogen and clinical significance of bacterial colonization of double-J stents after pyeloplasty in children.

PATIENTS AND METHODS

The medical files of 82 consecutive children (22 girls, 60 boys) who underwent pyeloplasty at a tertiary pediatric medical center in 2000-2007 were reviewed. Additional inclusion criteria were sterile urine preoperatively and placement of an indwelling double-J stent during surgery. Intravenous gentamicin was administered prior to pyeloplasty and stent removal; cephalexin was administered postoperatively until discharge. Children with a postoperative urinary tract infection (UTI) received full-dose antimicrobial treatment followed by prophylaxis until stent removal.

RESULTS

Median patient age at surgery was 11 months (1 month-17.5 years). Forty-nine stents were inserted on the left side, 32 on the right, and one bilaterally. Cultures showed bacterial colonization in 58 cases (70.7%); 15 (25.8%) grew Staphylococcus (coagulase negative and positive). Eight children had febrile UTI postoperatively; in four the stent was colonized by Enterococci and in one by Proteus; three were sterile. There was no statistically significant association between positive stent culture and febrile UTI, patient age or sex, or stent laterality. The study was potentially limited by its observational design, small sample size, and the selective antibiotic treatment of patients with UTI which may have affected stent bacterial resistance.

CONCLUSION

Bacterial colonization is not uncommon in double-J stents retained for several weeks after pyeloplasty, but is usually not clinically significant. Enterococcus is the most frequent pathogen.

First Report of the Parasitic Plant Orobanche aegyptiaca Infecting Olive

Broomrapes (Orobanche spp.) are obligatory parasitic plants that infect the root system of vegetables and field crops worldwide resulting in severe damage. Five broomrape species are known as significant parasites of crops in Israel: O. aegyptiaca Pers., O. cernua Loefl., O. cumana Wallr., O. crenata Forssk., and O. ramose L. (1,2). Recently, O. aegyptiaca was found to parasitize roots of young olive trees (Olea europaea) in a 1-year-old plantation located in Esdraelon Valley, Israel (voucher specimens deposited in Newe-Ya'ar Weed Herbarium, Ramat Yishay, Israel). To our knowledge, this is the first time that a tree in general and olive in particular has been reported to serve as host for O. aegyptiaca. Washing the root system clearly verified connections between the parasite and olive roots. Cross sections of an attachment site confirmed the development of functional haustoria. Trees were planted in a field where tomatoes had been previously parasitized by O. aegyptiaca for several years. In April 2001, many O. aegyptiaca plants emerged under each olive tree in a total area of 0.3 ha. Additional emergence of O. aegyptiaca was observed until July 2001. The high level of Orobanche infection did not lead to visible damage in the trees. However, the mature parasite developed massive amounts of seeds, serving to increase the population of O. aegyptiaca in the field. References: (1) D. M. Joel and H. Eizenberg. Three Orobanche species newly found on crops in Israel. Phytoparasitica 30:187, 2002. (2) C. Parker and C. R. Riches. Parasitic Weeds of the World. CAB International, Wallingford, UK, 1993.