EAL

FNOA: Antioxidants (2011-2012)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To document the natural history of nutritional status as Alzheimer dementia progressed to advance understanding of dietary and nutrient requirements in this compromised population.

Inclusion Criteria:

Community-dwelling patients
Early stage of probable Alzheimer dementia diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders IV criteria
Mini-Mental State Examination (MMSE) score of more than 22 or at state three to four on the Reisberg Global Deterioration Scale
Aged 65 years or older
Had an active caregiver
Spoke either English or French
Were physically well with no significant weight loss (defined as more than 4.5kg during a six-month period or more than 2.2kg during a one-month period) during the previous year
Able to provide informed consent at recruitment
Willing to commit for the 18-month study period
Controls had to meet the same criteria and also had to be cognitively intact.

Exclusion Criteria:

Class III or more severe heart failure
COPD requiring home oxygen therapy or oral steroids
Cancer treated by radiation therapy, chemotherapy or surgery in the five years before enrollment
Inflammatory digestive disease
Any other chronic illness likely to interfere with diet or participation in the study.

Description of Study Protocol:

Recruitment

Community-dwelling patients were recruited with their principal caregiver from memory clinics in Montreal by the memory clinic nurse or coordinator, and then contacted by the Nutrition-Memory Study coordinator, a professional dietitian
Healthy controls were recruited from a pool of hospital volunteers and from the general public by word of mouth and matched to Alzheimer dementia patients by age.

Design

Case-control study.

Statistical Analysis

Target sample size was 35 individuals per group providing adequate power to detect a weight loss of more than 5% in one year
Descriptive analyses were carried out to examine central tendencies and bivariate analyses were done to compare Alzheimer dementia patients and controls on variables of interest, stratifying by age
Contingency table analyses and the chi-square statistic were used to compare distributions of variables of interest across groups, parametric tests (T-tests for independent samples) were used to compare means of the groups with normally distributed data, and the equivalent non-parametric tests (Mann Whitney U, Wilcoxon Rank Sum) were conducted with non-normal distributions
Repeated measures ANOVA on time were carried out for each nutrient of interest, contrasting patients and controls with complete data at all time periods.

Data Collection Summary:

Timing of Measurements

Subjects were interviewed at four to five time points across an 18-month period.

Dependent Variables

Current diet and supplement use were assessed monthly by two food records and 24-hour diet recalls using adapted data collection techniques among patients, and analyzed using CANDAT with the 2001b Canadian Nutrient File
Anthropometric measurements: Weight, height, several muscle circumferences, waist and hip measurements, skinfold thicknesses, grip strength
Non-fasting blood samples.

Independent Variables

Subjects with Alzheimer dementia
Cognitively intact subjects.

Control Variables

Age.

Description of Actual Data Sample:

Initial N

42 community-dwelling patients and 64 cognitively intact controls were recruited.

Attrition (final N)

36 patients (61% women) and 58 controls (78% women):

666 records/recalls from patients
1,678 records/recalls from controls.

Age

Patients mean age: 77.8±4.6 years
Controls mean age: 73.7±5.5 years.

Other Relevant Demographics

There were no differences between patients and control subjects in education, self-assessed health at baseline or perceived financial adequacy.

Anthropometrics

Subjects were age-matched, but overall patients were older than controls (P<0.0001).

Location

Montreal, Canada.

Summary of Results:

Key Findings

Nutrient intake from diet and supplements were higher in the control subjects, with significant differences in energy, the macronutrients, calcium, iron, zinc, vitamin K, vitamin A and dietary fiber, as well as n-3 and n-6 fatty acids
At all study periods, Alzheimer patients had higher intake of folate than controls
Repeated-measures ANOVA confirmed these observations among balanced groups of participants aged more than 70 years with full nutrient data during 12 months' of follow-up
Mean Elderly Nutrition Screening Tool scores among Alzheimer dementia patients aged more than 70 years at baseline and the second follow-up were 3.9±1.8 and 4.1±1.6, respectively, consistent with moderate risk of undernutrition
No controls were at high risk at any time.

Nutritional Risk Among Alzheimer Dementia Patients and Controls Aged More than >70 Years Assessed at Two Study Periods in the Nutrition-Memory Study

Nutritional Risk	Group	Study Time Period: T0 [n(%)], P = 0.001	Study Time Period: T2 [n(%)], P = 0.003
Low	Patient	9 (27.3)	4 (14.8)
	Control	24 (66.7)	18 (52.9)
Moderate	Patient	17 (51.5)	18 (66.7)
	Control	12 (33.3)	16 (47.1)
High	Patient	7 (2.2)	5 (18.5)
	Control	--	--

Author Conclusion:

Dietary intakes by persons with Alzheimer dementia are poor compared to cognitively intact age-matched controls. Suboptimal diet is evident early in the onset of the disease. This vulnerable population would benefit from systematic dietary assessment and intervention to prevent further deterioration in food consumption and increased nutritional risk.

Funding Source:

Not-for-profit

Alzheimer Society of Canada, Consortium Cognition et Viellissement

Other non-profit:

Reviewer Comments:

Subjects were age-matched, but overall patients were older than controls (P<0.0001). Authors note the following study limitations:

Relatively small number of participants recruited as a convenience sample
Some methodological variability was necessary to collect data from patients, which could limit inference, although modifications to study design and data collection were limited to those deemed necessary for minimizing subject fatigue and potential frustration.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	N/A
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	N/A

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		???
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		No
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	No
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	No
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	???
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	Yes
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		???
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	N/A
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	N/A
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	???
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	N/A
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	???
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	N/A
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	Yes
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	Yes
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes