Nutritional and Functional Indicators and Their Association With Mortality Among Older Adults With Alzheimer's Disease

Predictors for survival in patients with Alzheimer's disease: a large comprehensive meta-analysis

The prevalence of Alzheimer's disease (AD) is increasing as the population ages, and patients with AD have a poor prognosis. However, knowledge on factors for predicting the survival of AD remains sparse. Here, we aimed to systematically explore predictors of AD survival. We searched the PubMed, Embase and Cochrane databases for relevant literature from inception to December 2022. Cohort and case-control studies were selected, and multivariable adjusted relative risks (RRs) were pooled by random-effects models. A total of 40,784 reports were identified, among which 64 studies involving 297,279 AD patients were included in the meta-analysis after filtering based on predetermined criteria. Four aspects, including demographic features (n = 7), clinical features or comorbidities (n = 13), rating scales (n = 3) and biomarkers (n = 3), were explored and 26 probable prognostic factors were finally investigated for AD survival. We observed that AD patients who had hyperlipidaemia (RR: 0.69) were at a lower risk of death. In contrast, male sex (RR: 1.53), movement disorders (including extrapyramidal signs) (RR: 1.60) and cancer (RR: 2.07) were detrimental to AD patient survival. However, our results did not support the involvement of education, hypertension, APOE genotype, Aβ42 and t-tau in AD survival. Our study comprehensively summarized risk factors affecting survival in patients with AD, provided a better understanding on the role of different factors in the survival of AD from four dimensions, and paved the way for further research.

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.

The association between low calf circumference and mortality: a systematic review and meta-analysis

PURPOSE

Low calf circumference is an important indicator of malnutrition and has been widely studied, especially among older adults. However, data on the association between low calf circumference and mortality have been inconsistent. This systematic review was aimed to quantify this association.

METHODS

The internet databases (PubMed, Embase, ScienceDirect and Cochrane Library databases) were systematically searched from inception to November 01, 2021 for studies investigating the association between low calf circumference and mortality. A random effects model was adopted to pool the relevant data.

RESULTS

Low calf circumference was associated with a higher risk of mortality than normal calf circumference, with a pooled HR of 2.42 (95% CI 1.97-2.97, I² = 74.3%). In addition, this association between low calf circumference and morality was still statistically significant in the subgroup analysis across different settings, including hospitals (pooled HR = 2.63, 95% CI 1.93-3.58), nursing homes (pooled HR = 2.49, 95% CI 1.76-3.54), and communities (pooled HR = 2.22, 95% CI 1.60-3.07). Other subgroup analyses based on different cutoffs of calf circumference showed that, compared to individual with normal calf circumference, participants with low calf circumference had an increased risk of mortality (pooled HR = 2.66, 95% CI 2.06-3.43) when using the Asian Working Group for Sarcopenia (AWGS) criterion (≤ 34 cm for males and ≤ 33 cm for females). Similar results were found when the Mini Nutritional Assessment (MNA) criterion (≤ 31 cm) was used, with a pooled HR of 2.11 (95% CI 1.59-2.81).

CONCLUSION

Calf circumference, which is simple and convenient to measure, could be used to stratify the high-risk group, as low calf circumference was significantly associated with mortality among patients. Interventions, including exercise and nutrition programs, could be conducted promptly once low calf circumference is detected.

Calf Circumference and All-Cause Mortality: A Systematic Review and Meta-Analysis Based on Trend Estimation Approaches

OBJECTIVES

To perform a systematic review and meta-analysis and quantify the associations of total mortality with calf circumference (CC) in adults 18 years and older via combining various analyses based on empirical dichotomic CC, continuous CC, and dose-response CC.

METHODS

We conducted a systematic search of relevant studies in PubMed, EMBASE, Cochrane Library, and Web of Science published through April 12, 2022. This systematic review includes longitudinal observational studies reporting the relationships of total mortality with CC. We calculated the pooled relative risk (RR) and 95% confidence interval (CI) of total mortality with CC per 1 cm for each study and combined the values using standard meta-analysis approaches. Newcastle-Ottawa scale (NOS), Grading of Recommendations, Assessment, Development and Evaluations approach (GRADE), and the Instrument for assessing the Credibility of Effect Modification Analyses (ICEMAN) were assessed for meta-analyses.

RESULTS

Our analysis included a total of 37 cohort studies involving 62,736 participants, across which moderate heterogeneity was observed (I2=75.7%, P<0.001), but no publication bias was found. Study quality scores ranged from 6 to 9 (mean 7.7), with only three studies awarded a score of 6 (fair quality). We observed an inverse trend between total death risk and CC per 1 cm increase (RR, 0.95, 95% CI, 0.94-0.96; P<0.001; GRADE quality=high). Only a very slight difference was found among residents of nursing homes (6.9% mortality risk reduction per one cm CC increase), community-dwellers (5.4%), and those living in hospitals (4.8%), respectively (P for meta-regression=0.617). Low credible subgroup difference was found based on the ICEMAN tool.

CONCLUSIONS

Calf circumference is a valid anthropometric measure for mortality risk prediction in a community, nursing home, or hospital.

Weight loss in Alzheimer's disease, vascular dementia and dementia with Lewy bodies: Impact on mortality and hospitalization by dementia subtype

OBJECTIVES

Loss of weight is associated with cognitive decline as well as several adverse outcomes in dementia. The aim of this study was to assess whether weight loss is associated with mortality and hospitalization in dementia subtypes.

METHODS

A cohort of 11,607 patients with dementia in Alzheimer's disease (AD), vascular dementia (VD), or dementia with Lewy bodies (DLB) was assembled from a large dementia care health records database in Southeast London. A natural language processing algorithm was developed to established whether loss of weight was recorded around the time of dementia diagnosis. Cox proportional hazard models were applied to examine the associations of reported weight loss with mortality and emergency hospitalization.

RESULTS

Weight loss around the time of dementia was recorded in 25.5% of the whole sample and was most common in patients with DLB. A weight loss-related increased risk for mortality was detected after adjustment for confounders (Hazard ratio (HR):1.07; 95% confidence interval (CI):1.02-1.15) and in patients with AD (HR: 1.11; 95% CI: 1.04-1.20), but not in DLB and VD. Weight loss was associated with a significantly increased emergency hospitalization risk (HR: 1.14; 95% CI: 1.08-1.20) and in all three subtypes.

CONCLUSIONS

While there were associations with increased hospitalization risk for all three subtype diagnoses, weight loss was only associated with increased mortality in AD. Weight loss should be considered as an accompanying symptom in dementia and interventions should be considered to ameliorate risk of adverse outcomes.

Comparing the Performance of Calf Circumference, Albumin, and BMI for Predicting Mortality in Immobile Patients

Background

Immobile patients often suffer from malnutrition and low calf circumference (CC), a potential surrogate marker of low muscle mass, which has been widely explored as a link with mortality among patients with inconsistent results. In addition, studies comparing CC, BMI, and albumin to predict mortality among immobile patients are limited. The aim of our study was to compare the performance of these three parameters for predicting mortality among immobile patients.

Methods

This is a secondary analysis of our previous study consisting of immobile patients, age>18 years. Data were collected between November 2015 and March 2016 by trained nurses through a case report form (CRF) that included clinical data and sociodemographic variables. In addition, anthropometric parameters, including body weight, height and calf circumference, were also measured. The outcome of our study was mortality with follow-up length being 90 days. Multivariate linear and logistic regression analysis were adopted to identify the association between CC and mortality, and a receiver operating characteristic curve analysis was also used to compare the performance of CC, BMI, and albumin.

Results

Of the 387 patients who were included (51.42% male), with an average age of 61.22 (SD=15.18), the prevalence of mortality was 5.43%. The results showed that, after full adjustment, calf circumference was a protective factor for reducing the risk of mortality (OR=0.79; 95%CI:0.65–0.96). Meanwhile, immobile patients with low calf circumference had an increased risk of mortality, compared to those whose condition was normal (OR=4.24; 95%CI:1.07–16.74). Receiver operating characteristic curve analysis showed that CC combined with albumin (AUC=0.812; 95% CI=0.733–0.890) had the highest AUC value compared to calf circumference (AUC=0.759; 95%CI:0.662–0.856), BMI (AUC=0.653; 95%CI:0.538–0.767) and albumin (AUC=0.735; 95% CI:0.638–0.832), respectively, in predicting mortality in immobile patients.

Conclusion

The relationship between calf circumference and mortality was significantly negative and low calf circumference was associated with a high risk of 90-day mortality, compared to those with normal calf circumference. The combined calf circumference with albumin had good discrimination in predicting mortality among immobile patients. Therefore, it can routinely be used in a clinical setting by medical staff to predict mortality in immobile patients, as it is easy to obtain.

Indicators of dementia disease progression in primary care: An electronic health record cohort study

BACKGROUND AND PURPOSE

The objectives were to assess the feasibility and validity of using markers of dementia-related health as indicators of dementia progression in primary care, by assessing the frequency with which they are recorded and by testing the hypothesis that they are associated with recognised outcomes of dementia. The markers, in 13 domains, were derived previously through literature review, expert consensus, and analysis of regional primary care records.

METHODS

The study population consisted of patients with a recorded dementia diagnosis in the Clinical Practice Research Datalink, a UK primary care database linked to secondary care records. Incidence of recorded domains in the 36 months after diagnosis was determined. Associations of recording of domains with future hospital admission, palliative care, and mortality were derived.

RESULTS

There were 30,463 people with diagnosed dementia. Incidence of domains ranged from 469/1000 person-years (Increased Multimorbidity) to 11/1000 (Home Pressures). An increasing number of domains in which a new marker was recorded in the first year after diagnosis was associated with hospital admission (hazard ratio for ≥4 domains vs. no domains = 1.24; 95% confidence interval = 1.15-1.33), palliative care (1.87; 1.62-2.15), and mortality (1.57; 1.47-1.67). Individual domains were associated with outcomes with varying strengths of association.

CONCLUSIONS

Feasibility and validity of potential indicators of progression of dementia derived from primary care records are supported by their frequency of recording and associations with recognised outcomes. Further research should assess whether these markers can help identify patients with poorer prognosis to improve outcomes through stratified care and targeted support.

The Impact of Diet Type on Weight Loss in Patients with Alzheimer's Disease

OBJECTIVES

To compare differences in weight loss in patients with Alzheimer's disease on normal, diabetic, or texture-modified diets.

METHODS

This prospective interventional study examined the data of patients with Alzheimer's disease who were admitted to a long-term care hospital in Japan from February to April 2013. Dietary elements and weight loss over a 3-month period were examined. Results: Of the 75 patients examined, 6 were on a normal diet, 10 were on a diabetic diet, and 59 were on a texture-modified diet. Weight loss was significantly associated with body weight, Mini Nutritional Assessment®, and diet type. In the non-malnourished patients, there was a significant difference between the three types of diets in terms of eating rate and weight loss.

CONCLUSION

Diet type was independently associated with weight loss in patients with Alzheimer's disease. Research using larger sample sizes is necessary to eliminate the differences between these diet types.