Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To determine whether there is a difference in RMR values between subjects who spend the evening in a clinical setting and subjects who spend the evening before measurements at home.
Inclusion Criteria:
  1. Understand and give written consent
  2. Healthy volunteers
Exclusion Criteria:
  1. Refusal to consent
  2. Not meeting inclusion criteria

Steady state: For the 3 clinical and 3 home measures, a VO2 within ±25 mL/min was applied.

Description of Study Protocol:

6 randomized RMR measurements: 3 measurements were made after subjects slept the evening before the measurements in their home (H1, H2, H3) and 3 after they slept in a clinical setting (C1, C2, C3).

ANTHROPOMETRIC

Fat %, fat-free mass, Weight

CLINICAL

Heart rate, VO2

  • Resting energy expenditure:
  • IC type: metabolic cart-model 2900
  • Equipment of Calibration: Yes
  • Coefficient of variation using std gases: Yes
  • Rest before measure (state length of time rested if available): yes, = 7hr of sleep
  • Measurement length: 30 min
  • Steady state: ? YES, stringent; Used a criterion of repeated measurements of VO2 within ± 25 mL/min was applied; If this standard was not met subjects were asked to return for an additional RMR measurement under those same conditions; N=4 subjects failed to meet the std within their 6 tests;
  • Fasting length: 12 h
  • Exercise restrictions XX hr prior to test? Yes, 24 h
  • Room temperature: 22 C
  • No. of measures within the measurement period: not specified
  • Were some measures eliminated? Yes; if VO2 data point that was not within ± 30 mL/min of the mean VO2 for that trial was discarded to eliminate any erroneous values.
  • Were a set of measurements averaged? Yes
  • Coefficient of variation in subjects measures? YES, stringent; Used a criterion of repeated measurements of VO2 within ± 25 mL/min was applied; If this standard was not met subjects were asked to return for an additional RMR measurement under those same conditions; N=4 subjects failed to meet the std within their 6 tests;
  • Training of measurer? Yes
  • Subject training of measuring process? Yes

DIETARY

Standardize the meal each night before the measurement

Data Collection Summary:
  • Outcome(s) and other measures
  • Oxygen consumption (VO2)
  • Heart rate (HR)
  • Ventilation (VE)
  • Respiratory exchange ratio (PER)
  • Height
  • Weight

Blinding used: Not applicable

Description of Actual Data Sample:

Actual Sample

N= 10 (4 males, 6 females)
Mean age: 26.1

Statistical tests

ANOVA, student’s T-test

Summary of Results:

Subject Characteristics (n=10)

  • Mean±SD
  • Height, cm 170.9 ± 9.6:
  • VO2 Max, mL/kg/min 53.2 ± 8.2
  • Fat, %,  14.6 ± 3.4
  • Weight (1) 66.4 ± 15.6 (Night before first RMR)
  • Weight (2) 66.6 ± 15.4 (Weight after 3rd RMR)
  • Weight (3) 66/6 ± 15.4 (Weight after 6th RMR)

There were no significant differences (p<0.05) in oxygen consumption (VO2, mL/min), RMR, or respiratory exchange ratio (RER) between any of the 6 RMR measurements, or between the mean values for the 3 home trials vs. the three clinical trials (i.e., 4.4 kJ/min ± 0.83 (1.05 kcal/min ± 0.20) vs. 4.4 kJ/min ± 0.92 (1.05 kcal/min ± 0.22).

There were no significant differences in RMR measurements whether expresses as kJ/min, kJ/kg body wt/ht or kJ/g fat-free mass/hr (P< 0.05).

Room temp reported at: 22 C

Author Conclusion:
  • “RMR measured after the subjects transported themselves to the testing facility the morning of the RMR measurement was not different from RMR measured when the subjects spent the night in the facility where the RMR was measured.”
  • “Having subjects spend the night in a clinical setting is expensive, requires special facilities, and requires a more substantial amount of time for both the researcher and the subject than does RMR measurements conducted when the subjects transport themselves to the testing site the morning of the assessment. Therefore, it is recommended that the following criteria be met before RMR is measured:
    1. No formal exercise for the 24-h period immediately before the RMR measurement begins
    2. A 12-h fasting before testing, with the measurement made in the early morning
    3. Repeated measurements with defined limits of acceptable test (e.g., VO2 ± 25 mL/min)
    4. HR monitoring for the 8-10 h period before measurement
    5. Rest with the face mask or ventilated hood in place for = 30 min before the actual measurement period begins.”
Funding Source:
Government: NIH
Reviewer Comments:

Strengths

  • Detailed measurement protocol with heart rate monitoring that increases subject compliance with pre-measurement conditions.

Generalizability/Weaknesses

  • Results are limited to healthy adults. Whether or not the same recommendations still hold true in ill patients are not known.
  • Small gender representation
  • RMR measures taken in a semi-recumbent position; unable to determine if applied to supine position.
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? N/A
  1.3. Were the target population and setting specified? N/A
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? N/A
  2.2. Were criteria applied equally to all study groups? N/A
  2.3. Were health, demographics, and other characteristics of subjects described? N/A
  2.4. Were the subjects/patients a representative sample of the relevant population? N/A
3. Were study groups comparable? N/A
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? N/A
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  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? 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.) N/A
  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? N/A
  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? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? N/A
  7.2. Were nutrition measures appropriate to question and outcomes of concern? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? N/A
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? N/A
  7.5. Was the measurement of effect at an appropriate level of precision? N/A
  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? N/A
  8.2. Were correct statistical tests used and assumptions of test not violated? N/A
  8.3. Were statistics reported with levels of significance and/or confidence intervals? N/A
  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? N/A
  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? N/A
  9.2. Are biases and study limitations identified and discussed? N/A
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? N/A
  10.2. Was the study free from apparent conflict of interest? N/A