Unintended Weight Loss in Older Adults

UWL: Caloric Needs (2007)

Citation:

Schneider SM, Al-Jaouni R, Pivot X, Braulio VB, Rampal P, Hebuterne X.  Lack of adaptation to severe malnutrition in elderly patients.  Clin Nutr 2002;21(6):499-504.

PubMed ID: 12468370
 
Study Design:
Cross-Sectional Study
Class:
D - Click here for explanation of classification scheme.
Quality Rating:
Positive POSITIVE: See Quality Criteria Checklist below.
Research Purpose:

To evaluate the effects of aging per se on body composition and resting energy expenditure in malnourished patients.

Inclusion Criteria:
  • C-reactive protein < 5 mg/l
Exclusion Criteria:
  • BMI > 20
  • C-reactive protein > 5 mg/l
  • Anorexia nervosa
  • Those who were not ambulatory
Description of Study Protocol:

Recruitment

Patients referred for chronic malnutrition between June 2000 and June 2001.

Design:  Cross-Sectional Study 

Blinding used (if applicable):  not applicable 

Intervention (if applicable):  not applicable 

Statistical Analysis

Comparisons between groups were made with unpaired t tests.  ANOVA was used for the comparisons within groups.  A search for factors related with the distribution of fat free mass, body cell mass, and the ratio of REE to FFM was performed.  Logistic regressions were performed to anlayze the impact of these variables on FFM, BCM, FM and REE/FFM.

Data Collection Summary:

Timing of Measurements

REE performed in morning after overnight fast.

Dependent Variables

  • REE assessed by indirect calorimetry using standard protocol
  • Body composition assessed by bioelectrical impedance

Independent Variables

  • Subjects separated into 2 groups based on age above or below age 70
  • Subjects separated into 3 groups based on BMI:  18.5 - 20, 16 - 18.5, and < 16
  • Height, weight
  • Triceps skinfold
  • Mid-upper arm circumference

Control Variables

 

Description of Actual Data Sample:

Initial N: 97 patients.  26 female and 19 male middle-aged subjects, 26 female and 26 male elderly subjects

Attrition (final N):  as above

Age:  middle-aged mean age:  48 +/- 15 years, elderly mean age:  79 +/- 6 years

Ethnicity:  not mentioned

Other relevant demographics:

Anthropometrics:

Location:   France

 

Summary of Results:

  Middle-Aged REE Elderly REE
BMI 18.5 - 20 1274 +/- 141 kcal/24 hr 1228 +/- 153 kcal/24 hr
BMI 16 - 18.5 1214 +/- 187 kcal/24 hr 1100 +/- 142 kcal/24 hr
BMI < 16 1083 +/- 190 kcal/24 hr 963 +/- 121 kcal/24 hr

Other Findings

In middle-aged patients, body composition remained stable between moderate (BMI 16 - 18.5) and severe (BMI < 16) malnutrition, with similar values of fat-free mass, body cell mass, and fat mass as percentages of body weight, whereas in elderly patients malnutrition occurred at the expense of fat free mass and body cell mass, with unchanged fat mass absolute values.

REE/FFM values remained stable in middle-aged patients at every stage of malnutrition, whereas they increased in elderly patients along with their degree of malnutrition.

In multivariate analysis, both body composition and REE/FFM were influenced by age, sex, BMI and mid-arm circumference. 

 

Author Conclusion:

In conclusion, compared to middle-aged patients, weight loss in the elderly involves a preferential decrease in lean body mass and body cell mass, implying the clinical consequences of malnutrition.  Furthermore, they maintain a high-energy expenditure that may worsen their nutritional status.  This wasting may involve the superimposition of a disease process that reduces dietary intake on a background of sarcopenia.  A better understanding of the underlying mechanisms, especially at the muscle level, as well as an easier access to body composition measurement in the hospital, are needed, to be able to prevent elderly patients at risk of malnutrition from developing malnutrition when a stress occurs, and to be able to refeed them more efficiently.

Funding Source:
University/Hospital: Archet University Hospital, University of Nice, Jean Minjoz University, University of Besancon (All France)
Reviewer Comments:
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? Yes
  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? Yes
3. Were study groups comparable? Yes
  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? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  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? Yes
  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.) Yes
  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? N/A
  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? Yes
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  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? N/A
  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? N/A
  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? N/A
  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? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  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? Yes
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? N/A
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