Unintended Weight Loss in Older Adults

UWL: Association With Outcomes (2009)

Citation:

Zuliani G, Romagnoni F, Volpato S, Soattin L, Leoci V, Bollini MC, Buttarello M, Lotto D, Fellin R. Nutritional parameters, body composition, and progression of disability in older disabled residents living in nursing homes. J Gerontol A Biol Sci Med Sci. 2001; 56(4): M212-M216.

PubMed ID: 11283193
 
Study Design:
Longitudinal, case-control study.
Class:
C - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:

To examine the relationship between nutritional status and the risk for further decline in physical function in a sample of older, functionally impaired residents living in a nursing home.

Inclusion Criteria:

From a sample of 344 elderly nursing home residents (272 females, 72 males) enrolled in the Istituto di Riposo per Anziani (IRA) study, a subset of individuals were selected for this specific analysis. All subjects resided at the IRA located in Padua, Northern Italy. Inclusion criteria were as follows:

  • Age 65 years or older
  • Resided at the IRA for at least two months prior to the initiation of the study
  • No evidence of acute illness at the time of observation or for 30 days prior to the time of observation
  • No diagnosis of terminal cancer or severe liver or kidney disease
  • Must be independent in at least two activities of daily living (ADLs) as defined by a Katz score of A through E at baseline and considered at risk for worsening disability over the two-year follow-up period.
Exclusion Criteria:

Subjects were excluded from this specific analysis if they:

  • Were younger than 65 years old
  • Resided at the IRA for less than two months prior to the start of the study
  • Had clinical evidence of acute illness within 30 days of the time of observation
  • Had been diagnosed with a terminal cancer or severe liver or kidney disease
  • Were considered fully disabled as defined by dependence in all or all but one ADL (Katz classes F and G)
  • Died during the two-year follow-up period
  • Lost only one ADL during the two-year follow-up period.
Description of Study Protocol:

Recruitment

Subjects meeting inclusion criteria were recruited from a population of older nursing home residents residing at the Istituto di Riposo per Anziani (IRA). 

Design

Longitudinal, case-control study.

Functional status, defined by the loss of ADLs and classified by the Katz index, was measured at baseline and at the completion of a two-year follow-up period by geriatricians working in the nursing home. Subjects were divided into two groups based on the presence of worsening disability, defined as loss of two or more ADLs during the follow-up period. Baseline characteristics, including anthropometric parameters, laboratory values and health status, were compared according to functional status at the two-year follow-up.

Blinding Used

Anthropometric parameters were measured in all subjects according to standardized methods by the same physician who was blinded to the subjects' Katz score. 

Statistical Analysis

  • Baseline characteristics were compared according to functional status at the two-year follow-up by using unpaired Student's T-test for continuous variables and the X²  test or Fischer's Exact Test for categorical variables
  • The association of single variables with the change in functional status at two-year follow-up was evaluated by univariate logistic regression
  • Multivariate logistic regression analysis was used to identify variables independently associated with worsening functional status. 
Data Collection Summary:

Timing of Measurements

  • Functional status, measured by independence in ADLs and classified by the Katz index, was measured at baseline and repeated at the two-year follow-up
  • The number of drugs prescribed was assessed at baseline and at the two-year follow-up
  • Weight, height, tricipital and subscapular skinfold thickness (SST), waist-to-hip circumference and body composition (determined by tetrapolar BIA) was measured at baseline
  • Serum total protein, iron, albumin, transferrin, total cholesterol, triglycerides and HDL cholesterol were measured at baseline
  • Age, gender and chronic medical conditions were assessed at baseline.

Dependent Variables

The number of ADLs lost during the two-year follow-up period.

Independent Variables

  • Gender
  • Age
  • Chronic medical conditions
  • Drugs prescribed
  • Blood samples analyzed for albumin, tranferrin, total cholesterol, HDL cholesterol and hemoglobin
  • Anthropometric measures: Waist-to-hip ratio, body mass index (BMI), body cell mass (BCM), subscapular skinfold thickness.
Description of Actual Data Sample:
  • Initial N: 344 individuals met inclusion criteria for the IRA study. 172 individuals were excluded from this particular analysis because of dependence in all or all but one ADL. 52 subject died within the two-year follow-up period. 22 subjects who lost only one ADL at follow-up were excluded from this particular analysis.
  • Attrition (final N): 98 individuals (40 individuals in Group 1 with stable or improved functional status over the two-year follow-up and 58 individuals in Group 2 with functional decline defined as loss of two or more ADLs over the two-year follow-up)
  • Age: 79.8±7.8 years (Group 1), 82.7±6.6 years (Group 2)
  • Other relevant demographics: Gender rates were 74% females in Group 1, 85% females in Group 2
  • Anthropometrics: Group 2 (individuals with functional decline defined as loss of two or more ADLs over the two-year follow-up) was significantly older, took significantly more prescribed drugs, had lower serum albumin, lower total cholesterol, lower HDL cholesterol, lower hemoglobin, lower subscapular skinfold thickness, lower WHR and had lower BCM at baseline when compared to Group 1 (individuals with stable or improved functional status)
  • Location: Istituto di Riposo per Anziani (IRA) in Padua, Northern Italy.
Summary of Results:

 

Baseline Variables

Group 1 (Two-year ADLs Constant or Improved from Baseline)

Group 2 (Two-year ADLs Worsened)

P-value

Gender (percent female)

74% 

85%

0.18*

Age (years)

79.8±7.8

82.7±6.6 

0.05*

Number of chronic diseases

3.0±1.3

3.4±1.3 

0.35 

Number of drugs taken

Baseline

Two-year follow-up

 

2.9±1.7

3.4±1.8

 

4.2±2.3

4.4±2.3 

 

0.01*

0.03* 

Number of lost ADLs

Baseline

Two-year follow-up

 

 

1.6±0.9

1.4±0.9

 

 

2.0±1.1

5.0±1.0

 

 

0.34*

0.001**

Albumin (g per dL) 4.48±0.4 4.27±0.35  0.01* 
Transferrin (mg per dL) 260±59 228±38  0.003* 
Total cholesterol (mg per dL) 226±42 205±43  0.03*
HDL-c (mg per dL) 51.2±17 44.8±11.5  0.04* 
Hemoglobin (g per dL) 13.9±1.3 13.1±1.3  0.009*
SST (mm) 15.8±4.9 12.9±5.5  0.01* 
WHR 0.97±0.1 0.91±0.1  0.01* 
BMI (kg/m²) 26.9±3.9  25.1±4.6  0.07* 
BCM (kg) 17.9±5.2  15.9±3.5  0.05* 

 * Group 1 vs. Group 2 unpaired T-test.

** Group 1 vs. Group 2; unpaired T-test and Group 2 baseline vs. two-year follow-up; paired T-test.

Other Findings

  • Deteriorating functional status (more than two additional lost ADLs) was associated with baseline albumin levels (Tertile 3 vs. Tertile 1; odds ratio, 0.16; 95% confidence interval, 0.04 to 0.67) and subscapular skinfold thickness (Tertile 3 vs. Tertile 1; odds ratio, 0.06; 95% confidence interval, 0.006 to 0.50)
  • After multivariate adjustment, the odds ratio for increasing disability was more than four in subjects with decreasing body cell mass, compared with subjects with a stable body cell mass
  • Body Cell Mass (BCM) decreased by 0.1kg in Group 1 (two-year ADLs constant or improved) and by 2.4kg in Group 2 (two-year ADLs worsened)
  • The odds ratio for increasing disability in subjects with decreasing BCM was 4.94 (95% CI) compared to subjects with stable and increased BCM
  • A stepwise, dose-response relationship between two-year BCM reduction and two-year decline in functional status showed the degree of BCM reduction was strongly related to the number of additional ADLs lost at the two-year follow-up (test for trend, P=0.003).
Author Conclusion:

Older, disabled nursing home residents with a two-year deteriorating functional status were characterized at baseline by a "worse" nutritional status when compared with disabled subjects with stable and improved ADLs. Signs of malnutrition seem to predict the worsening in functional status in older disabled nursing home residents. BCM declines proportionally to the loss of ADLs over time, suggesting the existence of a strong relationship between BCM loss and the deterioration of functional status in institutionalized older individuals.

Funding Source:
University/Hospital: University of Ferrara, Italy;Istituto di Riposo per Anziani, Padua, Italy;Geriatric Hospital, Padua, Italy.
Reviewer Comments:
  • Small number of subjects
  • Disabled nursing home residents; not generalizable to a free living population
  • In addition to significantly lower nutrition parameters at baseline (which was the focus of the investigation), Group 2 (declining functional status at two-year follow-up) was significantly older and took more prescription drugs at baseline; both factors might have contributed to the loss of ADL
  • Body cell mass was measured indirectly by BIA, and it is possible that age, sex, hydration, etc., could have led to over- or under-estimation of body compartments
  • No consideration of new incidence of disease over the two-year follow-up period, which may have contributed to the loss of ADLs
  • While no significant differences were observed in the principal disease reported at baseline, Group 2 had a higher prevalence of cognitive impairment (32%) when compared with Group 1 (13%) and a higher prevalence of Parkinson's Disease (15% in Group 2, compared to 6% in Group 1), both of which might have contributed to the loss of ADLs.
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) Yes
  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) Yes
 
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? Yes
  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? Yes
  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? 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? ???
  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? 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? No
  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? ???
  10.1. Were sources of funding and investigators' affiliations described? No
  10.2. Was the study free from apparent conflict of interest? ???