Association Between Blood Biochemical Factors Contributing to Cognitive Decline and B Vitamins in Patients With Alzheimer's Disease

Low pre-albumin but not thiamine predicts cognitive deficits in adolescents post-Fontan and healthy controls

BACKGROUND

Low pre-albumin, body mass index, and thiamine levels have been associated with poor nutritional status and cognitive/memory deficits in adult heart failure patients. However, the relationship of these nutritional/dietary intake biomarkers to cognition has not been assessed in adolescents post-Fontan procedure and healthy controls.

METHODS

This is a cross-sectional study. Adolescents (14-21 years of age) post-Fontan completion were recruited from paediatric cardiology clinics and controls from the community. The Montreal Cognitive Assessment was administered (normal ≥ 26), and blood draw (thiamine [normal 70-110 nmol/L] and pre-albumin levels [adolescent normal 23-45 mg/dL]) and the Thiamine Food Frequency Questionnaire were completed by all participants.

RESULTS

Seventy subjects, 40 post-Fontan (mean age 16 ± 1.6, female 51%, Hispanic 44%, hypoplastic left heart syndrome 26%) and 30 controls (mean age 16.8 ± 1.9, female 52%, Hispanic 66%), were participated. Post-Fontan group had lower median total cognitive scores (23 versus 29, p < 0.001), pre-albumin levels (23 versus 27, p = 0.013), and body mass index (20 versus 24, p = 0.027) than controls. Post-Fontan group had higher thiamine levels than controls (127 versus 103, p = 0.033). Lower pre-albumin levels (< 23) and underweight body mass index were associated with abnormal total cognitive scores (p = 0.030). Low pre-albumin level (p = .038) was an independent predictor of worse cognition.

CONCLUSION

Lower pre-albumin was an independent predictor for worse cognition in adolescents post-Fontan. Lower pre-albumin levels may reflect chronic liver changes or protein-losing enteropathy seen in Fontan physiology. These findings highlight the possibility for nutrition-induced cognitive changes.

An investigation into the potential association between nutrition and Alzheimer's disease

Background

Malnutrition is the most common nutritional issue in Alzheimer's disease (AD) patients, but there is still a lack of a comprehensive evaluation of the nutritional status in AD patients. This study aimed to determine the potential association of various nutritional indices with AD at different stages.

Methods

Subjects, including individuals with normal cognition (NC) and patients diagnosed with AD, were consecutively enrolled in this cross-sectional study. Demographics, body composition, dietary patterns, nutritional assessment scales and nutrition-related laboratory variables were collected. Binary logistics regression analyses and receiver operating characteristic (ROC) curves were used to indicate the association between nutrition-related variables and AD at different stages.

Results

Totals of 266 subjects, including 73 subjects with NC, 72 subjects with mild cognitive impairment due to AD (AD-MCI) and 121 subjects with dementia due to AD (AD-D) were included. There was no significant difference in dietary patterns, including Mediterranean diet and Mediterranean-DASH diet intervention for neurodegenerative delay (MIND) diet between the three groups. Lower BMI value, smaller hip and calf circumferences, lower Mini Nutritional Assessment (MNA) and Geriatric Nutritional Risk Index (GNRI) scores, and lower levels of total protein, albumin, globulin, and apolipoprotein A1 were associated with AD (all p < 0.05). Total protein and albumin levels had the greatest ability to distinguish AD from non-AD (AUC 0.80, 95% CI 0.74-0.84, p < 0.001), increased by combining calf circumference, MNA score and albumin level (AUC 0.83, 95% CI 0.77-0.88, p < 0.001). Albumin level had the greatest ability to distinguish NC from AD-MCI (AUC 0.75, 95% CI 0.67-0.82, p < 0.001), and MNA score greatest ability to distinguish AD-MCI from AD-D (AUC 0.72, 95% CI 0.65-0.78, p < 0.001).

Conclusion

Nutritional status of AD patients is significantly compromised compared with normal controls, and tends to be worsened with AD progresses. Early identification and intervention of individuals with nutritional risk or malnutrition may be significantly beneficial for reducing the risk, development, and progression of AD.

Association between dietary vitamin B1 intake and cognitive function among older adults: a cross-sectional study

BACKGROUND

This study aims to investigate the relationship between vitamin B1 intake and cognitive function in older adults.

METHODS

This cross-sectional observational study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. A total of 2422 participants were included in the analysis, with dietary vitamin B1 intake being determined by averaging two 24-h dietary recalls. Cognitive function was assessed using three cognitive function tests: the Digit Symbol Substitution Test (DSST) for processing speed, the Animal Fluency Test (AFT) for executive function, a Consortium to Establish a Registry for Alzheimer's disease (CERAD) subtest for memory. Test-specific and global cognition z score was created. Multivariate linear regression models were used to explore the association between vitamin B1 and cognitive function.

RESULTS

2422 participants, aged 60 years and older, were included from NHANES across two survey cycles (2011-2014). Higher vitamin B1 intake was associated with higher DSST, AFT scores (P < 0.001) as well as the global cognition z score (P = 0.008). In the fully adjusted model, as compared to the lowest quartile (Q1), the highest quartile (Q4) of vitamin B1 intake was related to higher DSST score (β = 2.23, 95% CI 0.79 ~ 3.67) and global cognition z sore (β = 0.09, 95% CI 0.02 ~ 0.16). The association between dietary vitamin B1 intake and cognitive function scores in US adults is linear. There was no detected significant statistical interaction between these variables.

CONCLUSIONS

Increased dietary intake of vitamin B1 was associated with better cognitive function in individuals aged over 60.

Blood levels of circulating methionine components in Alzheimer’s disease and mild cognitive impairment: A systematic review and meta-analysis

Background

Circulating methionine components have been reported to be associated with Alzheimer’s disease (AD) and mild cognitive impairment (MCI), although outcomes are not always consistent.

Materials and methods

Database searching was conducted using PubMed, Embase, Cochrane Library, and Web of Science from inception to 26 December 2021. In this study, two reviewers independently identified eligible articles and extracted the data. We used Joanna Briggs Institute (JBI) Critical Appraisal tools to assess the overall quality of the included studies. STATA software was employed to perform meta-analysis evaluating the standardized mean difference (SMD) with its 95% confidence intervals (CIs) using random-effects models. Evidence quality was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria.

Results

Totally, 30 observational studies were eligible for inclusion. Compared with cognitively normal controls, patients with AD had increased homocysteine (Hcy) levels in the blood [standardized mean difference (SMD) = 0.59, 95% confidence interval [CI]: 0.36–0.82, P = 0.000], plasma (SMD = 0.39, 95% CI: 0.23–0.55, P = 0.000), and serum (SMD = 1.56, 95% CI: 0.59–2.95, P = 0.002). Patients with MCI were not significantly different from controls (SMD = 0.26, 95% CI: –0.07–0.58, P = 0.127). Patients with AD or MCI did not significantly differ from controls of blood vitamin B12 levels, AD (SMD = –0.05, 95% CI: –0.19–0.08, P = 0.440), or MCI (SMD = 0.01, 95% CI: –0.16–0.17, P = 0.94). Some cohort studies have suggested that higher Hcy, methionine, and S-adenosylmethionine levels may accelerate cognitive decline in patients with MCI or AD, and vitamin B12 deficiency is a risk factor for the disease; however, the results of other studies were inconsistent. According to the GRADE system, all these outcomes scored very low to low quality, and no high-quality evidence was found.

Conclusion

Only Hcy levels in the plasma and serum were found to be inversely related to the risk of AD. However, due to the low quality of supporting these results, high-quality studies are needed to verify these findings.

Systematic Review Registration

http://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022308961.