HF: Protein (2017)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To investigate the nutrition adequacy and energy availability for physical activity in free-living, clinically-stable patients with chronic heart failure (CHF).

Inclusion Criteria:

CHF Subjects

  • Non-obese
  • Admitted for assessment or reassessment of indications for cardiac transplantation
  • Clinically stable
  • No evidence of fluid retention
  • Jugular venous pressure not raised
  • No changes in medication for at least seven days.

Control Group

  • Age and BMI matched
  • Very sedentary lifestyle
  • Weight stable for previous three months.
Exclusion Criteria:

CHF Subjects

  • Diabetes mellitus (DM)
  • Liver and renal insufficiency
  • Clinical signs of intestinal malabsorption.

Control Group

No signs or symptoms of DM or heart disease.

Description of Study Protocol:

Recruitment

  • Patients admitted to the Heart Failure Unit of Montescano Scientific Institute in Montescano-Pavia, Italy
  • Recruitment of controls was not described.

Design

Cross-sectional.

Statistical Analysis

  • Results are presented as the mean value ±SD
  • Comparisons between groups were performed with T-tests
  • Differences were considered statistically significant at P<0.05
  • Simple linear regression analysis was used to show possible correlations between plasma cortisol levels, plasma insulin levels, cortisol-to-insulin ratio and anthropometric parameters and resting energy expenditure.

 

Data Collection Summary:

Timing of Measurements

All measurements were completed once.

 Dependent Variables

  • Variable One
    • Anthropometric measurements included triceps skinfold thickness, midarm muscle circumference and body weight
    • Body weight (BW) was recorded and compared with the usual BW in the last six to 12 months before hospital admission. A non-intentional loss of over 10% of BW in the preceding year or more than 7.5% in the last six months was considered as a marker of energy depletion
    • Severe muscle protein malnutrition and loss of lean body mass was diagnosed when the arm muscle area (AMA) was below the fifth percentile
    • The co-presence of BW loss and a reduced AMA was diagnostic of combined calorie and protein malnutrition.
  • Variable Two: Resting energy expenditure (REE) was measured by indirect calorimetry and expressed in dcal per day, kcal per kg of BW and kcal per m2 of body surface
  • At 8:00 a.m., peripheral venous blood samples were drawn for assays of cortisol and insulin levels using the Cord-CT Radioimmunoassay Kit
  • Instructions were given on how to keep a seven-day food diary. The subjects were asked to collect three-day 24-hour urine samples for determination of urea nitrogen excretion (UNE) in g per 24 hours. After receiving the food diaries and UNE results, computerized nutritional analysis was used to calculate carbohydrate, protein, lipids and calorie (kcal1) intakes.
  • Total energy expenditure (TEE) was estimated as REEx1.3, where 1.3 is a correction factor for physical activity
  • Energy availability (EA) (kcal per day) for daily physical activity was calculated as kcal1- REE.

Independent Variables

Subjects with CHF.

Control Variables

Healthy subjects without CHF.

Description of Actual Data Sample:

Initial N

  • CHF: 57 (52 males, five females)
  • Controls: 49 (39 males, 10 females).

Attrition (Final N)

Same.

Age

  • CHF: 52±3 years
  • Controls: 44±16 years
  • P-value: NS.

Ethnicity

Not described.

Anthropometrics

They were matched for age, BMI and sedentary lifestyle.

Location

Italy.

Summary of Results:

 

Variables

All CHF Subjects
(Measures and Confidence Intervals)

All Controls
(Measures and Confidence Intervals)

Statistical Significance of Group Difference

REE (kcal/d)

1,499±228

1,309±315

P≤0.05

REE (kcal/m2)

870±98.7

777±113

P≤0.01

REE (percentage predicted)

103.2±11

92±13

P≤0.01

TEE (kcal/d)

1,949±296

1,702±409

P≤0.05

 

Variables

Normal Nourished CHF Subjects, N=26
(Measures and Confidence Intervals)

Normal Nourished Controls, N=33
(Measures and Confidence Intervals)

Statistical Significance of Group Difference

BMI (kg/m2)

25±1.5

25.1±1.8

P≤0.05

  

Variables

Malnourished CHF Subjects, N=31
(Measures and Confidence Intervals)

Malnourished Controls, N=16
(Measures and Confidence Intervals)

Statistical Significance of Group Difference

BMI (kg/m2)

21.5±2.9*

18.0±1.7

P≤0.05

REE (kcal/d)

1,461±192

1,156±242

P≤0.01

REE (kcal/m2)

872±94

749±123

P≤0.01

REE (percentage predicted)

105±12

92±13

P≤0.01

TEE (kcal/d)

1,898±250

1,503±315

P≤0.01

 * Normal CHF vs. Malnour CHF (P<0.1).

Only significant findings are presented in the tables above.

Other Findings

  • Negative calorie balance and nitrogen balance occurred in 70.1% and 59.6% of CHF patients, respectively, despite having similar calorie and nitrogen intakes as controls
  • Per the food diaries, patients with CHF ingested less lipids than controls. The percentage of carbohydrate and lipids were higher and lower, respectively, in CHF patients than in controls (P<0.01). The CHF subjects concentrated 82±8% ingested calories in the lunch and dinner each day. 35% of CHF patients confirmed in their diaries the persistence of digestive disturbances. 
  • Plasma cortisol levels, normal but higher in CHF patients than controls, were positively correlated with REE per kg (P<0.02)
  • Plasmal insulin concentrations were correlated with body weight (P<0.01), triceps skinfold thickness (P<0.01), AMA (P<0.01), but not with REE (NS).
Author Conclusion:

Non-obese, free-living patients with clinically-stable CHF have an inadequate intake of calories and protein and reduced energy availabillity for physical activity.

Funding Source:
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) 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? 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.) 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? N/A
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  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? No
  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.) No
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? No
  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? 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? Yes
  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? 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? 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? N/A
  7.7. Were the measurements conducted consistently across groups? N/A
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)? N/A
  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? ???