HF: Protein (2017)
To investigate the nutrition adequacy and energy availability for physical activity in free-living, clinically-stable patients with chronic heart failure (CHF).
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.
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.
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.
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.
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.
Variables |
All CHF Subjects |
All Controls |
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 |
Normal Nourished Controls, N=33 |
Statistical Significance of Group Difference |
BMI (kg/m2) |
25±1.5 |
25.1±1.8 |
P≤0.05 |
Variables |
Malnourished CHF Subjects, N=31 |
Malnourished Controls, N=16 |
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).
Non-obese, free-living patients with clinically-stable CHF have an inadequate intake of calories and protein and reduced energy availabillity for physical activity.
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? | ??? | |