EAL

SCI: Preventing Overweight (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine appropriate methods for the analysis of body composition in subjects with tetraplegia.

Inclusion Criteria:

Healthy males with SCI and complete motor lesions
20 to 40 years old
Duration of injury 1-10 years
Weight not greater than 10 % ideal (ideal defined as 48.07 kg for a male of 152.4 cm in height, and 2.72 kg for each additional 2.54 cm).

Exclusion Criteria:

None given.

Description of Study Protocol:

Recruitment

Selected from a total of 38 subjects

Design

Comparison of eight methods to measure body composition in a group of males with tetraplegia

Blinding used (if applicable): not applicable.

Intervention (if applicable): not applicable

Statistical Analysis

Overall mean percent body fat calculated from the 8 methods for each subject; mean differences were calculated for each method minus the overall mean
Simple linear regression analyses performed between each set of measurements and the overall mean to determine the line of best fit

Data Collection Summary:

Timing of Measurements

one time measurement

Dependent Variables

Body fat weight by

Bioelectrical impedance analysis (BIA) by tetrapolar impedance plethysmograph and surface electrodes (method of Segal)
Dual energy X-ray absorptiometry (DEXA) by total body scanner, model DPX, Lunar Radiation Corp)(methods of Wang, Heymsfield and Mazess)
Total body potassium (TBK) by whole-body ⁴⁰K counting using a 4 Pi counting chamber (method of Pierson)
Total body water (TBW) by dilution of titrated water corrected for exchangeable hydrogen isotope (method of Moore)
Anthropometric measurements using Lange skinfold calipers and measuring tape: biceps, triceps, subscapularis, chest, suprailiac, thorax, umbilicus, abdomen, thigh, arm and thigh length, and circumferences for mid-humerus, elbow, waist, chest, iliac crest and thigh

Steinkamp method (STK) using regression equations and multiple skinfold and circumference measurements to estimate fat (age, weight and gender specific)

Durnin and Womersley (DUR) using sum of four skinfold measures, gender and age to predict fat (relies on underwater weighing for validation)
Sloan (SLN) calculating body fat from calculated body density (relies on underwater weighing for validation)
Jackson and Pollack (J and P) using the Siri equation to convert body density to % fat (relies on underwater weighing for validation)

Independent Variables

SCI (tetraplegia)

Control Variables

age
race
gender
weight

Description of Actual Data Sample:

Initial N: 12 males with tetraplegia

Attrition (final N): 12

Age: Mean 28.5 years, range 20-38

Ethnicity: Caucasian

Other relevant demographics: none reported

Anthropometrics

height - 180.7 cm, range 167.6 - 193.0
weight - 66.8 kg, range 54.5 - 83.3

Location: New York City, NY (Mount Sinai Medical Center, Veteran Affairs Medical Center, Columbia University-St. Luke's/Roosevelt Hospital Center

Summary of Results:

Table 1: Results of fat weight (kg) by method

Variables	Mean±SE	Mean difference (method minus the mean)±SE	Significant difference from the mean
TBW	17.17±2.33	0.67±2.33	ns
BIA	16.14±2.22	-0.36±2.22	ns
DEXA	17.98±2.56	1.48±2.46	ns
TBK	32.92±2.51	16.43±2.51	p<0.01
STK	17.41±2.30	0.91±2.30	ns
DUR	12.56±1.67	-3.94±1.67	p<0.01
SLN	9.71±1.43	-6.79±1.43	p<0.01
J and P	8.14±1.12	-8.36±1.12	p<0.01

Other Findings

Author Conclusion:

Bioelectrical impedance analysis (BIA), dual energy X-ray absorptiometry (DEXA), total body water (TBW), and the Steinkamp anthropometric method are equally valuable for estimating fat in individuals with tetraplegia.

Funding Source:

Reviewer Comments:

Results are not generalizable to the full SCI population, as females, those with paraplegia, and those of race other than Caucasian were not included
STK anthropometric measurement is based on assumptions that may not be valid in those with SCI

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)	???
	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?		???
	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?	N/A
	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?	Yes
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?	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?	Yes
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?	No
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?	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?	Yes
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	Yes
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?	N/A
	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?	Yes
	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)?	No
	8.6.	Was clinical significance as well as statistical significance reported?	???
	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?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes