COPD: Effectiveness of Therapies (2007-2008)

Citation:

Vermeeren MAP, Wouters EFM, Geraerts-Keeris AJW, Schols AMWJ.  Nutritional support in patients with chronic obstructive pulmonary disease during hospitalization for an acute exacerbation:  a randomized controlled feasibility trial.  Clin Nutr 2004;23(5):1184-92.

PubMed ID: 15380912
 
Study Design:
Randomized Controlled Trial
Class:
A - Click here for explanation of classification scheme.
Quality Rating:
Neutral NEUTRAL: See Quality Criteria Checklist below.
Research Purpose:
To investigate the feasibility and effectiveness of energy- and protein-rich nutritional supplements during hospitalization for an acute exacerbation in nutritionally depleted COPD patients.
Inclusion Criteria:
  • Patients acutely admitted to hospital for exacerbation of COPD
  • COPD diagnosis based on GOLD criteria
  • Criteria for hospitalization were recent increase in breathlessness, cough and sputum production of sufficient severity to warrant hospital admission judged by an independent chest physician
  • Nutritional intervention criteria were a BMI < 22 or BMI < 25 and >5% weight loss in 1 month, or >10% weight loss in 6 months prior to admission
Exclusion Criteria:
  • Diabetes type 1
  • Thyroid or intestinal diseases
  • Carcinoma
Description of Study Protocol:

Recruitment

Methods not described.

Design:  Randomized Controlled Trial, 2-center

Blinding used (if applicable):  Double blind 

Intervention (if applicable)

  • 3 x 125 ml (2.38 MJ/day, 20% protein, 20% fat, 60% carbohydrate) nutritional supplementation
  • Placebo group received similar amounts of noncaloric fluid
  • Medical therapy (bronchodilator therapy and systemic glucocorticoids) and dietetic consultation were standardized but slightly different between 2 centers and dietary intake measured daily

Statistical Analysis

Differences in baseline characteristics between groups of 2 hospitals compared using Student's t test for independent samples.  For comparisons between intervention and control groups, ANOVA was used with day 8 values.

Data Collection Summary:

Timing of Measurements

Measurements completed upon admission and on days 4 and 8 of hospitalization.  Dietary intake and body weight assessed daily.

Dependent Variables

  • Body composition measured with bioelectrical impedance analysis 
  • Respiratory muscle strength assessed by measuring maximal inspiratory mouth pressure 
  • Quadriceps strength measured through dynamometer
  • Handgrip strength measured through handgrip dynamometer
  • Lung function:  FEV1 and inspiratory vital capacity calculated from flow volume curve
  • Symptoms including dyspnea at rest and while eating, loss of appetite, early satiety, bloating, and fatigue measured with visual analog scale 
  • Body weight, height
  • Arterial blood gases

Independent Variables

  • Disease severity
  • 3 x 125 ml (2.38 MJ/day) nutritional supplementation
  • Placebo group received similar amounts of noncaloric fluid
  • Medical therapy and dietetic consultation were standardized and dietary intake measured daily

Control Variables

 

Description of Actual Data Sample:

Initial N: 56 patients randomized

Attrition (final N):  47 completed the study, 23 in intervention (14 males, 9 females), 24 in placebo (18 males, 6 females).  Dropouts caused by medical problems (n = 4), alcohol withdrawal delirium (n = 1), and nausea after supplementation (n = 4).

Age: mean age intervention group:  66 +/- 8 years, placebo group:  65 +/- 10 years

Ethnicity: not mentioned

Other relevant demographics:

Anthropometrics:  No significant differences in BMI or FFMI between centers or groups at baseline.

Location:   The Netherlands

 

Summary of Results:

 

  Intervention

Placebo

Weight (kg) 1.37 +/- 1.3, P < 0.05 1.12 +/- 1.2, P < 0.05

Fat free mass (kg)

-0.5 +/- 2.6

-0.4 +/- 2.7

Fat mass (kg) 1.7 +/- 2.5, P < 0.05 1.5 +/- 2.5, P < 0.05
FEV1 (% predicted) 5 +/- 6, P < 0.05 5 +/- 9, P < 0.05
IVC (% predicted) 7 +/- 12, P < 0.05 10 +/- 17, P < 0.05
Pi-max (cmH2O) 3 +/- 10 3 +/- 13
Mean handgrip strength (kg) 0 +/- 3 0 +/- 3

Quadriceps strength (Nm)

3 +/- 8 2 +/- 9
Score of dyspnea at rest -3.8 +/- 2.5, P < 0.05 -4.3 +/- 3.2, P < 0.05
Score of dyspnea while eating -4.2 +/- 2.5, P < 0.05 -4.7 +/- 3.3, P < 0.05
Score of loss of appetite -2.7 +/- 3.2, P < 0.05 -2.6 +/- 2.9, P < 0.05
Score of early satiety -3.2 +/- 3.3, P < 0.05 -2.5 +/- 3.3, P < 0.05
Score of bloating -2.4 +/- 3.4, P < 0.05 -3.0 +/- 2.8, P < 0.05

Score of fatigue

-4.2 +/- 3.7, P < 0.05

-3.9 +/- 3.5, P < 0.05

Other Findings

47% of patients had experienced recent involuntary weight loss prior to admission.

Degree of weight loss was inversely related to resting arterial oxygen tension (r = 0.31, P < 0.05).

Nutritional intervention resulted in a significant increase in energy (16% vs placebo) and protein intake (38% vs placebo).

Over the period of hospitalization the mean energy intake in the intervention group was significantly higher compared to the placebo group (10.89 +/- 2.01 vs 9.40 +/- 2.54 MJ/day, P < 0.05).

Mean energy intake was 194 +/- 50 KJ/kg body weight compared to 159 +/- 42 kJ/kg body weight (P = 0.022).

Mean protein intake was 1.8 +/- 0.4 g/kg body weight vs 1.3 +/- 0.3 g/kg body weight (P < 0.01).

Mean duration of hospitalization was 9 +/- 2 days.

Relative to usual care, no additional improvements in lung function or muscle strength were seen after nutritional intervention. 

Author Conclusion:
In summary, nutritional supplementation is feasible and recommended protein intake could only be reached in the treatment group.
Funding Source:
Reviewer Comments:
Medical therapy slightly different between centers.  No significant differences in body weight gain and functional improvement between treated and control groups.  Authors note that mean hospital stay of only 9 days may be too short to show effectiveness of nutritional intervention. 
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? 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.) 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.) N/A
  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? Yes
  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? 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? ???
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  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? ???
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  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? Yes
  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? ???
  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? N/A
  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? No
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? No
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