SCI: Preventing Overweight (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
  1. To assess body composition of a group of SCI subjects several years after trauma
  2. To evaluate reliability of determining fat mass using skinfold thickness
  3. To investigate the relationship between injury duration and fat mass
Inclusion Criteria:

For SCI subjects:

  • Absence of cardiovascular diseases, diabetes, or hormonal pathologies
  • Lesion duration of at least 4 years

For control subjects:

  • Healthy
  • Matched to SCI for age and body mass index

 

Exclusion Criteria:
None provided.
Description of Study Protocol:

Recruitment

Methods not specified.

Design

Comparison of fat mass, fat free mass and bone mineral density by dual X-ray absorptiometry and skinfold measurements in 13 individuals with SCI and 13 healthy controls matched for age and BMI.

Blinding used (if applicable):  Not applicable.

Intervention (if applicable):  Not applicable.

Statistical Analysis

  • Student's t test  (comparisons between groups) for unpaired data
  • Simple linear regression analysis for relationship between variables
Data Collection Summary:

Timing of Measurements

One time measurement.

Dependent Variables

  • fat mass (FM) % measured or calculated by
    • dual-energy X-ray absorptiometry (DXA) scanning (Lunar DPX-IQ, MEC, Minster OH)
    • Durnin-Womersley equation from the value of four standard skinfolds (biceps, triceps, suprailiac, and subscapular) measured with a Holtain caliper (Crymych, UK).
  • fat free mass (FFM)% by DXA (as above)
  • bone mineral density (BMD)% by DXA (as above)

Independent Variables

  • SCI

Control Variables

  • age
  • BMI

 

Description of Actual Data Sample:

Initial N: 13 males with SCI (12 paraplegic, 1 tetraplegic); 13 healthy male controls

Attrition (final N): no attrition reported

Age: 33.8±5.4 yrs for SCI; 35.4±15.6 yrs for controls

Ethnicity: not reported

Other relevant demographics: none reported

Anthropometrics:

  • weight: 84.0±15.0 kg for SCI; 76.8±9.9 for controls
  • height: 181±6cm for SCI; 176±6 for controls
  • BMI: 25.7±4.3 kg/m2 for SCI; 24.5±2.4 for controls
  • WHR: 0.89±0.09 for SCI; 0.89±0.08 for controls

Location:

University of Milan, Italy

 

Summary of Results:

 Table 1: Percentage of body weight of fat mass by two methods

Variables

SCI group

Control group

 

Statistical Significance of Group Difference

Total body fat mass by DXA method (%) 31.1±8.2*

 

20.8±6.9 p<0.05 (control vs SCI)
Total body fat mass by skinfold method (%)

 19.6±4.2*

 22.3±6.8

 

 *by linear regression analysis, fat mass measured by skinfold method for SCI group was significantly lower than fat mass measured with DXA scanning (p<0.05)

Other Findings

  • Percentage of fat free mass was significantly lower in trunk and lower limbs, and upper limb fat free mass was significantly higher in the SCI group than the control group
  • No significant correlation was found between lesion duration and percentage of fat mass in the SCI group.
  • Total body bone mineral density didn't differ between groups

 

Author Conclusion:
Comparison between the skinfold method and DXA in paraplegics shows the substantial underestimation of fat mass performed with the four-skinfold method; and, the underestimation increases with fat mass percentage.
Funding Source:
University/Hospital: University of Milan
Not-for-profit
0
Foundation associated with industry:
Reviewer Comments:
  • Results are not applicable generally as they do not include women, ethnic diversity, and tetraplegic subjects
  • While subjects were age and BMI matched, other variables (ethnicity) were not matched
  • Only one skinfold formula was tested

 

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? 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? 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) 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.) 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? 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
  5.3. 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? 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? 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? 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? 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? ???
  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
  8.1. 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? Yes
  10.1. Were sources of funding and investigators' affiliations described? ???
  10.2. Was the study free from apparent conflict of interest? Yes