EAL

SCI: Lipid Abnormalities (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine the ethnic differences on the serum lipid profile including the serum lipoprotein (a) [Lp(a)] in a population of patients with chronic spinal cord injury (SCI).

Inclusion Criteria:

Inclusion groups included the neurologic deficit groups of complete tetraplegia (complete spinal injury above C8), incomplete tetraplegia (incomplete spinal injury above C8), complete paraplegia (complete spinal injury below T1) and incomplete paraplegia (incomplete spinal injury below T1). No other inclusion criteria were identified.

Exclusion Criteria:

None noted by author.

Description of Study Protocol:

Recruitment

Subjects were recruited from the Spinal Cord Damage Research Center, Department of Medicine and Rehabilitation Medicine, Mount Sinai Medical Center, New York, the Spinal Cord Injury Service, Veterns Affairs Medical Center, Bronx, NY, the Rehabilitation Research Training Center on Aging with Spinal Cord Injury, and Regional Spinal Cord System of Southern California, Rancho Los Amigos, Medical Center, Downey, CA, from May 1994 to May 1996 on 600 consecutive patients being seen for routine annual physical examinations.

Design

Serum lipid profiles were performed during a 24-month period from May 1994-May 1996, on 600 consecutive patients being seen for routine annual physical examinations. Ethnicity was determined by the subject's resopnse to questioning.

Blinding used (if applicable)

N/A

Intervention (if applicable)

N/A

Statistical Analysis

The results were reported as mean±standard error of the mean (SEM).
Analysis of variance (ANOVA) was used to determine significant differences among the ethnic groups for age, duration of injury (DOI), body mass index (BMI), Lp(a), total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol.
Scheffe post hoc analysis was applied for pairwise comparisons.
Chi-squared analyses were performed to determine differences in percent distribution for the lipid parameters among the groups for the ethnicity and among the subgroups for neurologic deficit, as well as for serum HDL cholesterol, LDL cholesterol, and Lp(a) categorized by serum values startified by cardiovascular risk.
Linear regression analyses were used to determine the relationships between the lipid variables and age or BMI, and between serum Lp(a) and age or BMI.

Data Collection Summary:

Timing of Measurements

Serum lipid profiles were obtained after an overnight fast during the routine annual physical examination

Dependent Variables

Total Cholesterol (mg/dL)
Triglycerides (mg/dL)
LDL cholesterol (mg/dL)
HDL cholesterol (mg/dL)
Total Cholesterol.HDL Cholesterol ratio
Lp(a) (mg/dL)

Independent Variables

Ethnicity

Control Variables

None described

Description of Actual Data Sample:

Initial N: 600 patients

Attrition (final N): 600 patients

Age: 37.6 ± 0.4 years

Ethnicity: White (n=159), Latino (n=282), African American (N=159)

Other relevant demographics:

DOI (yrs) 12.4±0.4

BMI (kg.m²) 24.99± 0.22

Com Tetra (n=185)

Incom Tetra (n=112)

Com Para (n=197)

Incom Para (n=106)

Anthropometrics:

Subjects in the white group were significantly older and had longer DOI than the Latino and African American groups.
Subjects in the white group had a greater proportion of complete tetraplegia than either the Latino or African American groups.
Subjects in the Latino and African American groups had greater proportions of incomplete paraplegia than in the white group.

Location:

New York, New York and Downey, CA

Summary of Results:

Lipid Profile and Lp(a)

Variables	Total SCI (n=600) Mean±SEM	White (n=159) Mean±SEM	Latino (n=282) Mean±SEM	African American (N=159) Mean±SEM
TC (mg/dL0	190±2	190±3	190±2	191±3
TG (mg/dL)	122±4	121±6	137±6	96±6*
LDL (mg/dL)	124±2	125±3	124±2	125±3
HDL (mg/dL)	42±1	40±1	39±1	47±1*
Tc/HDL	5.10±0.10	5.18±0.17	5.40±0.14	4.46±0.15*
Lp(a) (mg/dL)	19±1	18±1	15±1	29±2*

*P<0.05

Other Findings

Age, duration of SCI, and level and completeness of lesion had no significant effect on serum Lp(a) level.

Author Conclusion:

Ethnicity was found to be a strong determinant of the serum Lp(a) values, with the African American gourp having elevated levels compared with other groups. The association between serum LDL cholesterol and serum Lp(a) concentrations may be expected because these lipid fractions have similar lipid composition. The African American group had the highest serum HDL cholesterol concentrations and the lowest serum total to HDL cholesterol ratios. In persons with SCI, ethnicity plays a major role with regard to serum lipids.

Funding Source:

Government:

NIDDR

Reviewer Comments:

Level of activity and other lifestyle components (diet, alcohol, smoking) were not reported among subjects.

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?	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?		No
	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.)	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
	3.6.	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%.)	Yes
	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?		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?		???
	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)?	No
	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