SCI: Lipid Abnormalities (2007)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

To test the hypothesis that physically active men with tetraplegia have a more favorable risk profile of CHD than sedentary men with tetraplegia by comparing the lipid and (apo)lipoprotein concentrations of an active and sedentary group cross-sectionally.

Inclusion Criteria:
  • Participant in a separate study evaluating the effects of sport activity on performance capacity.
  • Subjects who were living independently and could propel a hand-rim wheelchair.
  • SCI male subjects with tetraplegia with lesions levels ranging from C5 - C8.
Exclusion Criteria:

Any subject with cardiovascular disease or "other medical complication" was excluded from this research.

Description of Study Protocol:


 24 men with tetraplegia, with lesion levels from C5 - C8 participated after having given informed written consent. 


  •  Subjects were divided into an active group (ACT, n=11), including subjects who were active in regular sports activities for at least 6 months, and a sedentary group (SED, n=13).
  • To determine whether active men with tetraplegia are at increased risk of CHD, the results were qualitatively compared with data from the able-bodied population.

Statistical Analysis

  • A Students t test for independent samples was applied to detect differences between groups for subject characteristics, behavioral factors, and the lipids and (spo)lipoproteins.
  • To investigate the influence of subject characteristics and behavioral factor on the lipids and (apo)lipoproteins, stepwise multiples regression analysis was applied, using as independent variables age, lesion level, completeness of the lesion (complete lesion =1, incomplete lesion = 0), time since injury, body mass, BMI, sport activity (sport participation =1, no sport participation = 0), smoking behavior, alcohol consumption, VO2 peak and family history of CHD (with family history of CHD = 1, without family history of CHD = 0).
  • Results were considered significant at p </= 0.05
Data Collection Summary:

Timing of Measurements and Measurements Used

  •  Blood samples were collected in the mroning or early afternoon.
  • Subjects were asked to eat a low-fat breakfast only (bread and tea) at least 2 hours before blood samples were taken.
  • Body mass was determined on a hospital scale.
  • Body mass index was defined as mass divided by the square of self-reported height.
  • Peak oxygen uptake  was determined as a measure of physical fitness in a separate mezimal wheelchair exercise test.

Dependent Variables

  • Total plasma cholesterol (TC)
  • High-density lipoprotein cholesterol (HDL-C)
  • Triglycerides (TG)
  • apolipoprotein-A1 (ApoA1)
  • apolipoprotein-B (ApoB)

Independent Variables

  •  Sports activity was defined as hours of sports participation per week, and ranged in ACT from 1.5 to 6.0 hours per week
    • All subjects of ACT participated in a weekly quad rugby training (1.5 h/wk)
    • Additional sports activities were wheeling (n=4), wheelchair dancing (n=1), wheelchair basketball (n=1), and table tennis (n=1)
  • Smoking behavior was defined as number of cigarettes smoked per day.
    • 4 subjects were smokers (2 in ACT and 2 in SED) and they smoked 2-15 cigarettes per day.
  • Age, lesion level, completeness of the lesion (complete lesion =1, incomplete lesion = 0), time since injury, body mass, BMI, sport activity (sport participation =1, no sport participation = 0), smoking behavior, alcohol consumption, VO2 peak and family history of CHD (with family history of CHD = 1, without family history of CHD = 0).




Description of Actual Data Sample:


Initial N: 24 men

Attrition (final N): 24 men (no attrition)

Other relevant demographics:

  • 4 subjects were smokers (2 in ACT and2 in SED) and they smoked 2-15 cigarettes per day.
  • Alcohol consumption ranged from 0 (n=7) to 30 glasses per week
  • 8 subjects (3 in ACT and 5 in SED) had a history of CHD in parents, brothers and/or sisters.
  • In ACT, 4 subjects had an incomplete lesion (ASIA Impairment Scale: D [n=3] and C [ n=1]), whereas all subjects in SED had a complete lesion.


  • There were no significant differences between groups in age, time since injury, body height, smoking behavior, and alcohol consumption.
  • Body mass and BMI were significantly lower, and VO2 peak was significantly higher, in ACT compared with SED.

Subject Characteristics & Behavioral Factors

Active Group


Mean (SD)

Sedentary Group


Mean (SD)

p Value
Age (yrs) 29.2 (11.8) 36.2 (9.3) 0.120
TSI (yrs) 7.2 (8.9) 4.6 (4.1) 0.338
Body mass (kg) 70.1 (16.0) 86.7 (20.5) 0.040
BMI 20.5 (4.1) 25.9 (5.3 0.012

Sport Activity


3.0 (1.7)    



1.5 (4.5) 1.5 (3.8) 0.997

Alcohol consumption


7.4 (7.9) 7.5 (10.3) 0.983
VO2 peak (mL/min/kg) 14.4 (4.5) 9.1 (2.5) 0.003
body height (m) 1.85 (0.06) 1.82 (0.06) 0.362


Summary of Results:



  •  ACT showed a significantly higher value for HDL-C an ApoA1/ApoB, and a lower ration TV/HDL-C, compared with SED ( p </= 0.05).
  • No significant differences were found between groups for TC, LDL-C, LDL-C/HDL-C, TG, ApoA1, ApoB, and HDL-C/ApoA1
  • BMI was the only significant determinant of TC/HDL-C, LDL-C/HDL-C, and HDL-C/ApoA1, explaining 24%, 18%, and 19% of the variance, respectively.
  • No differences in TC/HDL-C between ACT and SED are found when results are adjusted for BMI.
  • Age was the most important determinant of TC, TG, ApoB, and ApoA1/ApoB.
  • Age is a more important determinant than sports activity for ApoA!/ApoB although a difference was found between ACT and SED.
  • Sport activity was the only significant determinant of HDL-C, explaining 17% of the variance, irrespective of the other independent variables (including BMI, age, and lesion level).
  • No significant relationships were found for lesion level, body mass, family history for CHD, VO2 peak, smoking behavior and alcohol consumption.
  • There was a more favorable lipid and (apo)lipoprotein profile in a group of active men and tetraplegia compared to sedentary men with tetraplegia.
  • Lower levels of HDL-C and ApoA1/ApoB and higher levels of TC/HDL-C as found in SED in this research are associated with a higher risk of CHD.
  • Active persons with tetraplegia are at lower risk of CHD.
  • Multiple regression analysis showed that age and BMI were the most important determinants of most of the lipid and (apo)lipoprotein parameters, including TC/HDL-C adn ApoA1/ApoB.
  • BMI and age are more important parameters than sports activity for predicting TC/HDL-C and ApoA1/ApoB.
  • Differences in BMI, age, and lesion level may have influenced the results of the research.
  • Sports activity was the only significant determinant of HDL-C and can decrease the risk of CHD in men with tetraplegia.
Author Conclusion:
  • The results of this study sugest a positive influence of sport activit on HDL-C in men with tetraplegia, which may reduce th risk of CHD. 
  • Based on the depressed levels of ApoA1 and an increased level of ApoB, in combination with a normal LDL-C, both active and sedentary men with tetraplegia are at increased risk of CHD.
Funding Source:
University/Hospital: Rehabilitation Center of Amsterdam
Foundation associated with industry:
Reviewer Comments:

Small sample size.  Longitudinal research is required to establish causal relationship between training and risk factors of CHD in subjects with tetraplegia.

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? 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? Yes
  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? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? No
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) ???
  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? Yes
  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.) Yes
  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? 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? 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? No
  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? No
  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? No
  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? No
  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? No
  6.6. Were extra or unplanned treatments described? No
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? ???
  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? Yes
  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? 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)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? 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
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