EAL

SCI: Role of the Registered Dietitian (2007)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

Previous data supports the role of dietary habits in risk for coronary heart disease, in the general population with an increased risk for in individuals with spinal cord injury. This study was designed to assess the relationship of the dietary habits of community-dwelling individuals with spinal cord injury and their serum lipid status.

Inclusion Criteria:

Subjects had to be at least 18 years of age with a traumatic spinal cord injury.

Exclusion Criteria:

No exclusion criteria were reported.

Description of Study Protocol:

Recruitment

The total sample consisted of 189 adults (44 women, 145 men)
115 of the subjects were included because of enrollment in a previous study (31 females, 84 males) as a result of s random selection of a sampling frame within 13 counties surrounding Galveston, TX
10 additional men were selected "because they had been injured a long time" (cumulative sample 125)
10 more were recruited because they were injured after the age of 35 years (cumulative sample 135)
25 who were recently injured were recruited (cumulative sample 150)
15 Hispanics were included, based on "an updated sampling frame" (cumulative sample 165)
34 more were recruited during initial rehabilitation hospitalization and followed two years post-discharge (cumulative sample 189)

Design

Cross-sectional

Blinding used (if applicable)

N/A

Intervention (if applicable)

N/A

Statistical Analysis

Descriptive statistics of the dietary intakes and serum lipids were prepared for the total sample as well as by gender and race/ethnicity. Individuals with abnormal lipid levels based on NCEP Guidelines (1991, 1993) were identified for the total sample as well as by gender and race/ethnicity.

Spearman's rho used to examine relationship of:

dietary and serum lipids with age and time since injury
dietary lipids and serum lipids

Stepwise multiple regression was used to predict serum lipids from demographic, dietary intake and injury-related variables. Predictors were retained at P<0.05 and removed at P>0.10.

Data Collection Summary:

Timing of Measurements

Serum lipids were measured after an overnight fast. Food records were collected on the consecutive days chosen by the participant.

Dependent Variables

Serum cholesterol, HDL, LDL and triglycerides were measured using "standard laboratory techniques" from blood collected in the home after an overnight fast.
Dietary cholesterol (mg), total fat (g), saturated fat (g) and percent of energy from total and saturated fat were assessed using three-day food records. Portion-size estimation booklets were provided to aid in serving size reporting. Most days (percent not reported) were weekdays conducted on the days following record-keeping instructions. Intakes were assessed using a program developed by the University of Texas School of Public Health. Values used in the analysis represent a three-day mean intake for each nutrient.

Independent Variables

N/A

Control Variables

None

Description of Actual Data Sample:

Initial N: 189 (145 males, 44 females))

Attrition (final N): none reported (not all subjects provided all data points)

Age: 43.1±13.3 SD (19.16-81.89 years)

Ethnicity: 112 Caucasian (59.3%), 42 African American (22.2%), 33 Hispanic American (17.5%) and 2 Other (1.1%)

Other relevant demographics:

Time since injury: 12.46±10.4 years (0.46-46.97 years)
Tetraplegia (A, B, C - 78, 41.3%), Paraplegia (A, B, C - 74, 39.2%), Tetraplegia or paraplegia (D - 37, 19.6%)

Anthropometrics: N/A

Location:

Rehabilitation Research and Training Center in Community Integration for Individuals with Spinal Cord Injury sponsored by the National Institute for Disability and Rehabilitation Research, Houston, Texas

Summary of Results:

Variables	Women	Men
Dietary Cholesterol	2459±163	282±152
Total Fat (g)	68.9±29.4	70.9±29.6
Total Fat (% of kcals)	36.7±7.6	36.7±7.0
Saturated Fat	23.4±10.7	24.2±11.1
Saturated Fat (% of kcals)	12.4±	12.5±
Serum Cholesterol	195.9±36.4	194±35
HDL	46.2±11.7	43.7±10.0
LDL	120±35	121±34
Triglycerides	148±100	149±102

Variables	Caucasian	African American	Hispanic American
Dietary Cholesterol	246±132	315±175	308±187
Total Fat (g)	68.9±27.4	68.6±33.8	68.0±30.0
Total Fat (% of kcals)	36.2±7.6	38.8±6.7	35.8±8.6
Saturated Fat	23.2±10.3	23.8±12.4	23.2±9.6
Saturated Fat (% of kcals)	12.11	13.4	12.4
Serum Cholesterol	195±31	191±38	203±47
HDL	45.9±12.4	47.5±10.3	45.7±11.6
LDL	117.9±32.3	122±35	123±42
Triglycerides	155±98	107±38	177±141

Other Findings

Significant negative correlations were found for saturated fat (g and percent of energy, R=-0.21 and R=-.020, respectively) with time of injury and a positive association of age with serum cholesterol (R=0.23) and triglycerides (R=0.24). Serum triglycerides were only associated with percent of energy derived from total fat (R=-0.17).

Gender was a significant predictor of dietary cholesterol (B=0.156) and HDL (B=-0.332), while time since injury was a significant predictor of saturated fat (g and percent of energy, B=-.201 and R=-0.188, respectively). Age (R=0.273) and grams of saturated fat intake (R=0.158) were significant predictors of serum cholesterol. Age (R=0.325), African American race/ethnicity (R=-0.238) and time since injury (R=-0.196)were significant predictors of serum triglycerides.

Author Conclusion:

Interventions and nutrition education are needed to reduce dietary fat intakes and serum lipids, especially in men, with spinal cord injury. Further studies are needed to examine the the effect of dietary fat reduction interventions on serum lipids in persons with SCI as well to assess the long-term relationship between dietary fat intakes and serum lipids.

Funding Source:

Reviewer Comments:

This is a generally sufficient design to answer the question; however, the effect of age and gender on serum lipids should have been controlled in the analyses. Furthermore, the recruitment was a convoluted and difficult to follow. Issues about weekday vs. weekend intakes may be less impacted in the disabled, but should be further investigated for the differences in weekday and weekend intakes.

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)	N/A
	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)	N/A

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?	N/A
	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?	N/A
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
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?		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?		N/A
	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?	N/A
	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?	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?	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?	???
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		N/A
	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?	No
	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?	No
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