EAL

HF: Protein Needs (2008)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To investigate the adequacy of nutrition and calculated energy availability for the physical activity of non-obese patents with stable chronic heart failure (HF).

Inclusion Criteria:

Heart failure patients: Body mass index (BMI) under 25, stable New York Heart Association Class II to III chronic heart failure
Controls: Healthy, sedentary, matched.

Exclusion Criteria:

All others.

Description of Study Protocol:

Recruitment:Not described
Design: Cross-sectional
Blinding used: None
Statistical analysis: Not described.

Data Collection Summary:

Timing of Measurements

Food diaries were kept for seven days
24-hour urine was collected for three consecutive days
Resting energy expenditure (REE) was measured 12 to 14 hours after overnight fasting
Venous blood was drawn at 8:00 a.m. for cortisol and insulin values
All were performed once.

Dependent Variables

Variable One
- REE was measured 12 to 14 hours after overnight fasting
- Oxygen consumption and carbon dioxide production were measured at one-minute intervals and means of 60-minute measurements were used to calculate REE
- This calculation (kcal per day) was adjusted for body surface (kcal per m²)
- From REE the daily energy expenditure (TEE) was calculated
- The calorie balance was calculated as the number of kilocalories introduced in the diet per day, less the TEE.
Variable Two
- Nitrogen balance was calculated as nitrogen intake with food, less total nitrogen loss (g per 24 hours), which was equal to urea nitrogen excretion plus two g (loss of nitrogen from feces and skin)
- 24-hour urines were collected for three consecutive days.
Venous blood was drawn at 8:00 a.m. for cortisol and insulin values.

Independent Variables

Presence or absence of heart failure.

Description of Actual Data Sample:

Initial N: 55 HF (unknown gender) and 49 controls (unknown gender)
Attrition (final N): Same
Age: Not stated
Ethnicity: Venous blood was drawn at 8:00 a.m. for cortisol and insulin values
Anthropometrics: Controls were matched (no further description)
Location: Italy.

Summary of Results:

Variables	HF Group Measures and Confidence Intervals	Control Group Measures and Confidence Intervals	Statistical Significance of Group Difference
REE (kcal/m²)	870±13	777±15	P≤0.01
Calorie Intake (kcal/kg)	28.3±0.8	29.5±1.2	NS
TEE (kcal/day)	1,950±43	1,700±53	P≤0.01
Calorie Balance	-186±40	104±35	P≤0.01
Nitrogen Balance (g/day)	-1.7±0.4	2.2±0.5	P≤0.01
Nitrogen Intake	11.8±0.2	11.8±0.6	NS
Cortisol-Insulin Ratio	65.0±5.1	32±1.7	P≤0.01

Author Conclusion:

Non-obese patients with chronic HF did not have an adequate intake of calories and protein to support their metabolic needs for daily life activities
These patients have an important hypermetabolic state, with consequent protein breakdown.

Funding Source:

Reviewer Comments:

The authors did not describe the formula used to determine TEE from the REE.

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?	N/A
	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?	No
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	No
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		???
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	No
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	???
	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.)	???
	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?	N/A
	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?	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?		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?	???
	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?	???
	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?		???
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	No
	8.2.	Were correct statistical tests used and assumptions of test not violated?	???
	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?		No
	9.1.	Is there a discussion of findings?	No
	9.2.	Are biases and study limitations identified and discussed?	No
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?	???