EAL

Healthy Non-Obese Older Adults (2010-2012)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

Compare measured REE values with three predicted values
Compare the relationship with sleeping energy expenditure (SEE) and REE
Assess reproducibility of the results within each individual.

Inclusion Criteria:

Diseases that would not affect resting metabolic rate
Medications that would not affect resting metabolic rate
Normal dietary habits
Stable weights for six months
No evidence of physical or mental disease
Physical activities comparable from day-to-day
Normal blood pressures, pulse rates and body temperatures.

Exclusion Criteria:

Not meeting inclusion criteria
Diseases in subjects that were excluded: Disorders that might have affected their metabolic rate, such as high blood pressure, thyroid dysfunction, heart failure, infectious disease, COPD or anemia.

Description of Study Protocol:

Recruitment

Procedures not specified

Design

Cross-sectional study with repeat measures in a sub-sample

Blinding

Not applicable

Intervention

Not applicable

Statistical Analysis

Pearson's coefficient of correlation to assess the relationship between resting energy expenditure (REE) and independent variables
Stepwise multiple regression used to determine the best predictors of REE in this sample
Student's paired T-test
For reproducibility test: Performed on subjects with the highest REE (N=11) and the lowest REE (N=11).

Data Collection Summary:

Timing of Measurements

First measurement: measurement of REE for total sample:
- Measurement of sleeping energy expenditure (SEE) for sub-sample: Time interval after first measurement not specified
- Measurement of REE for reproducibility sample: Five months after first measurement.

Dependent variables

Measured REE and SEE [(VO₂, liters per minute), VCO₂ (l/min; ml/kg per minute), RQ, ventilation (liters per minute)
- IC type: Ventilated hood system during a half-hour; flow through canopy adjusted to the body weight of patient (25-50 liters per minute)
- Equipment Calibration: Calibrated at the start and end of every measurement using known concentration of gases (O₂ and N2)
- Coefficient of variation using standard gases: Yes or no
- Rest before measure (state length of time rested if available): 30 minutes
- Measurement length: 30 minutes
- Steady state: Evaluate if mention initial acclimatization and then continuous monitoring throughout measurement, if appropriate
- Fasting length: 10 hours overnight
- Exercise restrictions XX hours prior to test: Travel by car, bus or train to reduce physical activity
- Room temp: Not mentioned
- No. of measures within the measurement period: One
- Were some measures eliminated? None reported
- Were a set of measurements averaged? No
- Coefficient of variation in subjects measures? Assessed reproducibility within individuals; Performed second REE five months later in subjects with the highest REE (N=11) and subjects with the lowest REE (N=11)
- Training of measurer? Not reported
- Subject training of measuring process? Not on the first measurement but would occur on the measurement five months later
- Body composition measures: Bioelectrical impedance with the person in the supine position. FFM calculated using sex and fatness specific formulae Segal et al, 1988
- Sleeping energy expenditure measurements: REE was measured in N=30 (out of 40)
- IC type: Open circuit indirect calorimeter (14m³), equipped with bed, toilet, TV, chair Chambers measured by a dry gas meter; Ox paramagnetic analyzer and indirect CO₂ analyzer; calculated during the period of sleeping from 0:300 to 0:600 hours: Subjects stayed for 12 hours in a computerized open-circuit indirect calorimeter
- Monitored heart rate? Yes
- Body temperature? Yes
- Medications administered? Not identified.

Independent variables

Age
Weight
Height
BMI
Fat-free mass (FFM): Bioelectrical impedance (BI) (Segal et al).

Description of Actual Data Sample:

Initial N: Not given
Attrition (final N): N-40
- N=18 males
- N=22 females
Age: 65+8 years (range: 51-82)
- Males: 63+8 years
- Females: 66+7 years
Ethnicity: Not specified (Dutch?)
Other relevant demographics: None specified
Anthropometrics:

Men	Mean±SD	Range
Age	63±8	N/A
Weight, kg	81.1±11.0	40.8-73.7
Height, cm	N/A	N/A
BMI	26.46±6.8	N/A
Fat-free body mass	60.1±6.8	N/A
Women	Mean±SD	Range
Age, years	66±7	N/A
Weight, kg	64.8±7.1	N/A
Height, cm	N/A	N/A
BMI	25.5±2.6	N/A
Fat-free body mass	44.1±4.0	N/A

Location: Netherlands.

Summary of Results:

Resting Energy Expenditure in Elderly

Resting energy expenditure (REE) in the elderly (mean±SD)
	Males (N=18)	Females (N=22)	Total (N=40
REE (kcal)	1,733±205	1,330±155	1,512±269 range 1,106-2,145
REE (kcal/kg BW)	21.4±1.5	20.6±2.0	21.0±2.0 range 17.5±26.0
REE (kcal/kg FFM)	28.9±2.0	30.2±3.3	29.6±2.9 range 25.1±36.5

Measured REE of the 40 healthy volunteers was higher than predicted REE no matter what prediction equation was used
The HB equation under predicted the measured value by 7%
The Owen equation under predicted the measured value by 4%.

Measured and predicted resting energy expenditure (REE) (Mean±SD)
	Measured	Predicted Harris-Benedict	Predicted Schofield	Predicted Owen
REE (kcal)	1,512±269	1,420±244**	1,427±244**	1,461±240*

*P<0.05 OWEN vs. measured

**P<0.001 Schofield and Harris-Benedict vs. measured

Correlations between:

REE and FFM: R=0.88
REE and weight: R=0.85
REE and sex: 0.75
REE and age: 0.54.

Stepwise multiple regression

The combination of body weight, sex and age gave the best prediction for REE [R=0.921, SEE 111kcal]
REE (kcal)=1,641+10.7 weight (kg)-9.0 age (years)- 203 (sex) [one=male, two=female]
When body weight and age were used as the variables, the slopes of the regression lines were statistically indistinguishable. No separate regression lines were developed for men and women
84% of the variance in REE could be explained by weight, sex and age; the 95% prediction limits (two times the SEE) were wide (+225kcal per day). There was also a wide range for REE/BW (17.5-26.0kcal/kg) and for REE/FFM (25.1-36.5kcal/kg).

Reproducibility

The 22 subjects (mean age 64±8 years) who were measured twice showed no significant differences in REE between the two measurements
- There were also no significant differences in body weight and composition
- The test-retest correlation coefficient was high (R=0.96)
- The Standard error measurement of a single determination of 24-hour REE was 53kcal resulting in a within-subject co-efficient of variation (CV w) of 3.5%.

Sleeping energy expenditure

In the sub-group of 30 subjects that sleeping energy expenditure and REE was determined (mean age 69±7 years), the mean ratio of SEE: REE was 0.93±0.08.The difference between REE and Sleeping energy expenditure seems to be independent of REE.

Author Conclusion:

As stated by the author in body of report:

In our study, measured REE for healthy elderly people is higher than the predicted REE based on results from the most commonly used prediction equation of Harris-Benedict
The measured REE in the current study was also higher than predicted by the new equations published by Owen. This can be explained by the fact that REE in the study of Owen was measured mainly in younger people (males mean 38±16 years; females 35±12 years).
The impact of underestimation of, on average, 6% may not be neglected. Energy requirements are based on REE which accounts for about 65-70% of total energy expenditure; Further, for individuals the predicted REE may over- or underestimate actual REE by 10-20%. Therefore, it seems important to employ the most appropriate prediction equation when calculating daily energy requirements.
Conditions that vary in studies is that today’s adults have a different REE compared to their ancestors, as a result of climatic factors, level of physical activity, dietary habits and general level of health
Due to large variations in measured REE, predicted REE may over- or underestimate the actual REE by 10-20%
A CVw of 3.5% indicates both reasonable methodological precision and small within-subject variability. This small within-subject variation for both subjects with a high or low REE confirms the observation that there is a wide range of REE for healthy men and women over 50 years age.
Two recent studies have demonstrated sleeping energy expenditure to be 5% lower than REE; Therefore, overnight energy expenditure will be overestimated by 5-7% by the use of the REE-value
Due to small within-subject variation and methodological error in REE, only a single measurement is needed, which can be performed under strictly defined conditions on an outpatient basis.

Funding Source:

University/Hospital:

University of Limburg, University Hospital Maastricht

Reviewer Comments:

Strengths

Measured intra-individual variation over five months

Generalizability/Weaknesses

Study biases include convenience sampling
Small sample size
Proposed equation most applicable to population studied: Healthy elderly living in Maastricht, The Netherlands
An intervening variable measured but not controlled for in measured to predicted analysis is overweight/obesity
An important variable affecting REE measurement accuracy that was not described was defining steady state
These are important variables on formula accuracy” Rounded weight factor for females in the Owen formula.

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
	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
	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
	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
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
	1.	Was the research question clearly stated?	Yes
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.1.	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
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
	1.3.	Were the target population and setting specified?	Yes
	2.	Was the selection of study subjects/patients free from bias?	???
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?	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
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	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?	???
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
	3.	Were study groups comparable?	???
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)	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?	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.)	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?	No
	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?	No
	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
	3.5.	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
	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?	???
4.	Was method of handling withdrawals described?		???
	4.1.	Were follow-up methods described and the same for all groups?	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%.)	???
	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%.)	???
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	???
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	???
	4.4.	Were reasons for withdrawals similar across groups?	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
	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?	N/A
5.	Was blinding used to prevent introduction of bias?		N/A
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	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
	5.2.	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
	5.3.	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
	5.4.	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
	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.	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
	6.1.	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
	6.2.	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
	6.3.	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?	???
	6.4.	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
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments 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
	6.7.	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
	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.	Were outcomes clearly defined and the measurements valid and reliable?		???
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	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?	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?	???
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	???
	7.5.	Was the measurement of effect at an appropriate level of precision?	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?	No
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	No
	7.7.	Were the measurements conducted consistently across groups?	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?	Yes
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
	8.1.	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
	8.2.	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
	8.3.	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
	8.4.	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)?	No
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	No
	8.6.	Was clinical significance as well as statistical significance reported?	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?	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.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
	10.	Is bias due to study's funding or sponsorship unlikely?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes