SCI: Lipid Abnormalities (2007)

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

To present data on the natural history of changes in serum lipid levels and physical activity in 100 quadriplegic and paraplegic subjects during the first year following acute SCI.

Inclusion Criteria:

Males with acute spinal cord injury (SCI).

Exclusion Criteria:

None noted by author.

Description of Study Protocol:

Recruitment

  •  Subjects consisted of 100 consecutively admitted males with acute SCI. 
  • Controls were selected from the outpatient dental, eye, or orthopedic clinics.

Design

All subjects were evaluated with a detailed history, weight and height measurements, and a complete fasting lipid profile at baseline. 

Blinding used (if applicable)

N/A

Intervention (if applicable)

All SCI subjects underwent an 8-week standard physical rehabilitation program with daily muscle strengthening exercises, followed by standing in a frame and walking the parallel bars. 

Statistical Analysis

 Serum lipid levels were assessed against time by linear regression analysis.  Differences between groups at each time point were compared by an unpaired Student's t test.

Data Collection Summary:

Timing of Measurements

 Acute SCI patients were evaluated at baseline, 4, 16, 36, and 52 weeks after SCI for serum lipids, body weight, diet, medications, and rehabilitation activites. Lipids in control subjects were measured at a single time point.

Dependent Variables

  • Total Serum Cholesterol (TC)
  • Serum Triglyceride level (TG)
  • Serum HDL cholesterol (HDL)
  • Serum LDL level (LDL)
  • LDL/HDL ratio
  • Alcohol intake (drinks per day)
  • Cigarette smoking (packs per day)
  • Body weight
  • Height

Independent Variables

  • Paraplegia
  • Quadraplegia

Control Variables

 Not described.

Description of Actual Data Sample:

 

Initial N:

  • 100 males with acute SCI
  • 80 age-matched male ambulatory, non-SCI controls

Attrition (final N): 100 males with SCi and 80 controls

Age: mean age 45 years

Ethnicity:

Not described by author.

Other relevant demographics:

65 of the subjects were quadriplegics

35 of the subjects were paraplegics

Injury level ranged from C-1 to S-3

Anthropometrics:

All SCI subjects were stratified into categories according to level of physical activity.

  • Category 1: totally dependent in activites of daily living (ADL)
  • Category 2: used an electric or manual wheelchair and were in dependent for some ADLs
  • CAtegory 3: ambulated with or without assistance and were independent in all ADLs

In addition, all SCI subjects wre categorized into two groups based on changes in physical activity.

  • Group I  ; no change in physical activity after 52 weeks
  • Group II : increased physical activity from one category to another

Location:

Not described.

 

 

Summary of Results:

 Differences in serum lipid levels over time between groups

Variables

 

Quadriplegic

n=65

at 4 weeks

mean±SD

Paraplegic

n=35

at 4 weeks

mean±SD

Statistical Significance of Group Difference

At 4 weeks

P

Quadriplegic

n=65

at 52 weeks

mean±SD

Paraplegic

n=35

at 52 weeks

mean±SD

Statistical Significance of Group Difference

At 52 weeks

P

Controls

n=80

 

mean±SD

TC mg/dL

 163±3

178±5  <0.01 177±4  196±4  <0.01

 208±4

TG mg/dL

 113±3

 

 123.9±7  NS

 130±4

 136.7±7  NS

 148±7

LDL mg/dL

 112±2

 123±4  <0.05

 125±4

 130±5  NS

 138±5

HDL  28±1  34±1 <0.01   35±1  40±2  <0.05  42±4
LDL/HDL ratio  4.0±0.2  3.6±0.1  not described  3.5±0.1  3.2±0.1  not described  3.2±0.2

 

Other Findings

  • HDL cholesterol increased in 17%±3% in patients whose level of physical activity remained constant as compared with an increase of 30%±3% in patients whose physical activity increased.
  • Alcohol consumption in SCI patients decreased significantly during the first year after injury from 1.84±0.41 to 0.59±0.01 drinks per day (P<0.01).
  • Cigarette smoking decresed significantly from 1.15±0.46 to 0.13±0.05 packs per day (P<0.05). 
  • Body weight decreased nonsignificantly. 
Author Conclusion:

Serum HDL cholesterol is markedly depressed following acute SCI and gradually returns toward normal by one year. It is postulated that 44% of the increase in serum HDL is due to an increase in physical activity and 56% to the SCI itself.

Funding Source:
Government: VA Medical Center
University/Hospital: Brighman and Women's, Harvard Medical Center
Reviewer Comments:
  • Inclusion/exclusion criteria not clear
  • Health status for other chronic or acute diseases not described.
  • Groups may not have been comparable at baseline
  • Ethnicity not described
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? ???
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? ???
  2.3. Were health, demographics, and other characteristics of subjects described? ???
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
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
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? ???
  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? ???
  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")? Yes
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? ???
  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.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? ???
  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? ???
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? ???
  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? ???
  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? No
  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? ???
  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? No
  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? ???
  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)? ???
  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? No
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? No
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